After a couple weeks of false starts, equipment changes, troubleshooting and almost throwing several hundred dollars in vintage test equipment across the room I finally have, hopefully, a working combo of the three essentials to do this. A working trio of HP equipment: HP 8600 marker/HP 8601 sweeper generator and an HP oscilloscope rated at 100MHZ

If my friends who tried to help me with this before would like to hop back on board, maybe we can have a do over and try to see if I can follow discussions, theory and perform the hands on tasks resulting in finally…FINALLY seeing some alignment trace shapes on my scope. I’ll be working on the bench tomorrow after 1pm eastern daylight time setting some preliminary checks up. I appreciate all the input, time, knowledge and brainstorming provided in the previous thread. Thanks all!
Chris

So you have the working pair on hand? That is terrific.

Once the equipment is confirmed working and the interconnection cabling is in place, the use of the HP equipment will follow the published alignment documentation. The RCA split sound receiver alignments always begins with the sound IF and Sound discriminator alignment because the proper Video IF alignment is dependent upon the sound aligned first.

I confirmed frequency adjustments work but after moving on and trying the setup for the sweep characteristics setup, I'm getting nonsense on my scope. I think, the issue is my lack of knowledge on this HP 64600B oscilloscope. Most of my oscilloscope use is limited to hooking up a probe in a circuit, pressing "Auto" and comparing what my trace looks like as compared to what's in the service manual.

It must be in XY mode. You cannot use the "auto" button. This is where a cheap, basic analog scope is easier to use. You do not need high bandwidth at all.

I have it in XY mode. I can see the markers and move them but I’m not sure what this is supposed to look like. It’s a function confirmation protocol. Anyway, I think if I move straight to production of the sound discriminator wave and the 21.25 symmetrical trace for the sound IF, with help, I’ll probably learn more than I would going through all the tests. I’ve been in contact with the seller and after many email exchanges I’m confident in his statement the sweep generator works accurately.

Can you show some photos? of the Scope setting, the setting on the 8601a generator, the settings on the 8600a marker?

I am particularly curious what yiou have on the display to start so we may guide you in.

The cables and the sweep characteristics test are setup the way it is pictured in the manual on page 4-3. I put together the RF detector as you sketched out. There are two blanking inputs on the back of the marker generator so I plugged it into the one on the bottom...hey, I flipped a coin. They don't specify an RF frequency, only that the range selector be set as shown. At least the trace on the scope looks like a CRT! :banana::banana::banana: The tall, vertical line is the marker at approx. 106MHz on the counter but I don't think this sweep test is supposed to look like this, is it? My scope is set for XY input.

https://imagizer.imageshack.com/v2/1280x1024q70/924/J7X6oP.jpg

https://imagizer.imageshack.com/v2/1280x1024q70/922/GS9KQf.jpg

https://imagizer.imageshack.com/v2/1280x1024q70/923/wyCOtI.jpg

...and I assumed the ground hookups to the RF out and Y scope input on your RF detector schematic is the line on the bottom and the signal goes through the 1000pf cap and the diode etc?

The first thing I see is the sweep is set to full. That is the full bandwidth from 1.0MHz to 110MHz when the range is set to 110. To sweep across the center frequency indicated in the read out. Refer to page 3-2 in the manual.

Nest set the Sym Sweep with to 1.0MHz for aligning the sound IF and discriminator and fully clockwise to to the Video IF alignment.

Set the dial indicator to 21.25MHz to do the sound alignment and about 44MHz to do the Video IF alignment.

I generally use line truggering (lower left). On the 8600a the center button depressed for scope is correct for the sweep alignment. You press the CW when the generator is in CW to generate and measure the frequency of a fixed CW signal.

The scope I cannot see the settings but as Banderson indicated it must be in X-Y mode.

When it is working correctly, with the test detector, you should see a flat line. When you select a marker button, then rotate the control, you should see a bright marker dot move along the line. The marker display will indicate the exact frequency of the marker at that point. I typically set as you see from my CT-100 IF response, to have the 5 markers from left to right across the the response.

Are you inserting the detector circuit?

I switched on my 8601a, 8600a and the scope. I left the RF out to the scope Y input disconnected. The scope is in X-Y mode. The generator is set for a 3MHz sweep width across 50MHz. So it is sweeping from 48.5 MHz to 51.5MHz with 50.0MHz in the middle.

I set the markers across the band being swept with the center button of the marker selected and set to 49.99MHz. You will see it in the middle of the scope display as the brightest marker because the marker button is depressed.

You should see this BEFORE connected the RF.

Also a correction to my earlier instructions: Put the sweep trigger switch (lower left) to FREE. It eliminates the bright dot on the right which I believe is due to the sweep waiting for the next line trigger. Fee run is fine so long as the swwep speed when aligning is not set too high. (we can discuss that later when you get to that step).

Yes it’s in there. For the test of sweep characteristics. I’ll look at your instructions and work on it. It’s Bedtime for Bonzo right now. Talk with u tomorrow!!

I’m putting the HP manual aside and just following your instructions to the letter from now on! I’ll be able to do more on this tomorrow evening and most of the day Tuesday. I’ll be “working from home “ Tuesday!

Questions...

What is sitting on top of your counter? Is that something I need?

How are the cables connected between the sweep/generator and the counter? Forget the scope right now. I have everything disconnected to start from scratch.

So far, all I have hooked up is the cable to the aux out of the 8601

https://imagizer.imageshack.com/v2/1024x768q70/922/iLhZUS.jpg

On top of the marker are my wideband HP 403B AC Voltmeter and my HP 200D Generator. I used them for various testing. Most recently for audio distortion measurements in conjunctio with and HP 331A Distortion Meter. The 403B was locally $20, the 200D was free and the 331A was $40.

Attached is your photo with the connections.

Nope...have it all set the way you have it...all hooked up correctly and all levels set as pictured. I have a line with no markers and when the counter is on scope and I press the center marker button, I have a frequency readout that's jumping all over the place and no markers on the screen...just the straight horizontal line.

This is fu%$#ng hopeless. Just not gonna happen

Perhaps before throwing in any towels, or hitting it with a Sledgehammer, you could post pics of everything in detail, front and back, and how it's wired up and set and working (not-working), and perhaps someone who has the same type of set up can spot something that's being overlooked.

Thank you for the encouragement. Sometimes I need to walk away from these things for a few days and reboot my brain. Right now I can't even get this setup to put out a countable RF signal much less sweep and insert markers. I can't even reproduce what I posted a couple of days ago where at least, I saw markers albeit on a bizarre sweep trace that looked like a cone . Maybe my scope is messed up or something shorted in the sweeper or the counter. I don't know. Maybe this weekend, my mentors can walk me through this in real time from the most basic to where I can get a symmetrical swept trace with markers. Right now I'm pretty disgusted and a bit demoralized.

Please post picture of the front of your devices and the rear connections.

Regarding markers. Doesn't this use the z-axis on the scope for intensity modulation? Do you have that hooked up?

Please post picture of the front of your devices and the rear connections.

Regarding markers. Doesn't this use the z-axis on the scope for intensity modulation? Do you have that hooked up?

It does not use Z modulation. What it does is momentatily stops the sweep at the marker point to make it brighter. Notice the sweep inhibit connection.

Nope...have it all set the way you have it...all hooked up correctly and all levels set as pictured. I have a line with no markers and when the counter is on scope and I press the center marker button, I have a frequency readout that's jumping all over the place and no markers on the screen...just the straight horizontal line.

This is fu%$#ng hopeless. Just not gonna happen

You have to rotate the marker controls to se them. When they are within range, the selected markers when making the adjustment will cause the marker counter display to change. Try pushing in the buttons and rotating the marker controls.

Just be patient. It will work!

OK...I'll post pictures of everything

Aux out of the 8601 into counter on 8600

https://imagizer.imageshack.com/v2/1024x768q70/923/FofjCP.jpg

Blanking out of 8601 and into 8600

https://imagizer.imageshack.com/v2/1024x768q70/924/IoK12U.jpg
https://imagizer.imageshack.com/v2/1024x768q70/923/8Mdzez.jpg

Sweep Inhibit out of the 8601 into the 8600

https://imagizer.imageshack.com/v2/1024x768q70/923/7Mw1yh.jpg
https://imagizer.imageshack.com/v2/1024x768q70/922/YIk4N5.jpg

Sweep out of the 8601 and into the 8600

https://imagizer.imageshack.com/v2/1024x768q70/924/OIRBpK.jpg
https://imagizer.imageshack.com/v2/1024x768q70/924/88wFL8.jpg

Sweep out of the 8600 and into horizontal input on scope

https://imagizer.imageshack.com/v2/1024x768q70/924/MqCfrS.jpg
https://imagizer.imageshack.com/v2/1024x768q70/922/0xZGKP.jpg

8601 on and set for CW at 50MHz. 8600 showing frequency with the scope button pushed in.

https://imagizer.imageshack.com/v2/1024x768q70/923/BB0sIT.jpg
https://imagizer.imageshack.com/v2/1024x768q70/922/eIZndr.jpg

8601 set for a symmetrical 3MHz sweep around 50MHz at 0 dBm. Frequency displayed on 8600 shows a stable frequency read with the center button pushed in but actually the frequency display is almost unreadable as it flashes with jumbled frequencies all over the place. No markers on trace. No amount of turning the marker setting control to left and right extremes changes anything.

https://imagizer.imageshack.com/v2/1024x768q70/922/sjhNZv.jpg
https://imagizer.imageshack.com/v2/1024x768q70/922/V7UTf8.jpg
https://imagizer.imageshack.com/v2/1024x768q70/923/qmLHgZ.jpg
https://imagizer.imageshack.com/v2/1024x768q70/923/ehRgrE.jpg

I've tried all the other marker buttons with no change. Marker height adjustment on 8600 turned up almost full but there's no change no matter what I do. Scope is in X-Y mode.

He's using a digital scope, so I don't think sweep inhibit is going to work. It's not going to get brighter if the sweep pauses. I think he'll need to use the z-axis option.

Can you take a couple steps back so we can see how you have the cables connected?

I'd also go with a lower frequency than 50MHz. You goal is to align a set with 22MHz IF. The higher the frequency, the more strange effects pop up.

So, this is a case where a cheap analog oscilloscope from evil bay would help, but you can prob get the digital one to work!

He's using a digital scope, so I don't think sweep inhibit is going to work. It's not going to get brighter if the sweep pauses. I think he'll need to use the z-axis option.

Can you take a couple steps back so we can see how you have the cables connected?

I'd also go with a lower frequency than 50MHz. You goal is to align a set with 22MHz IF. The higher the frequency, the more strange effects pop up.

I posted photos of all the cable hookups. I do have a Textronix 60MHz analog scope but I don’t know how to set it to X-Y input

I posted photos of all the cable hookups. I do have a Textronix 60MHz analog scope but I don’t know how to set it to X-Y input

it should be quite easy, they all can do it!

My scope is too advanced for this? What the hell?

It's not too advanced. Digital operates in some fundamentally different ways than analog.
The longer the electron beam stays in one spot, the brighter it gets in an analog scope. Digitial does not work this way.

Thats a consequence of mixing gear from different eras.

It's hard to follow all the close up photos and read the descriptions.

It would be helpful is we could see your whole setup in one photos. See the whole cable from end-to-end. That way we can see how it is all hooked up.

What model Tek scope?

I hooked everything up the way Penthode documented in his photo. From sweeper to counter:
Aux out to counter
Inhibit to inhibit
Blanking to blanking
Sweep out to sweep in
Sweep out from 8600 to horizontal scope input

OK, well inhibit isn't going to work with your scope and you have nothing on the vertical so all you will see is a horizontal line. Meaning that, so far, it looks like it should.

I posted sequential photos of hooking up the cables one by one because these cables are 3 feet long and too jumbled up like a plate of noodles to follow from the 8601 to the 8600. But here you go as best I can

https://imagizer.imageshack.com/v2/800x600q70/923/iQf3hY.jpg
https://imagizer.imageshack.com/v2/800x600q70/922/BXK8Sz.jpg
https://imagizer.imageshack.com/v2/800x600q70/922/5QIGgG.jpg
https://imagizer.imageshack.com/v2/800x600q70/924/ONpyes.jpg
https://imagizer.imageshack.com/v2/800x600q70/923/OykxMm.jpg

OK, well inhibit isn't going to work with your scope and you have nothing on the vertical so all you will see is a horizontal line. Meaning that, so far, it looks like it should.

But I don't see markers...Penthode showed this setup without a vertical input and he had 5 markers on the horizontal trace. That's what I'm trying to reproduce but there are no markers.

Would a Textronix 465 make all of this easier if I can get my hands on a working one?

Would a Textronix 465 make all of this easier if I can get my hands on a working one?

you said you had an analog scope, what type is it?

In the latest picture but I haven’t used it in years and one of the beams is messed up

Just any plain old scope with a an X-Y display will work. Is something inhibiting the display? Make sure the scope is not set to trigger.

Without the RF connected you should see a horizintal line trace. The dots will appears when the marker controls are set mid position. Remember if the marker controls are set fully CW or CCW, you will not see the dots. (And CW in this case is Clock Wise!)

Let's look for the sweep line first. What is inhibiting the trace on the scope? If the sweep output of the generator is not reaching the x input of the scope, you should just see a dot in the center of the screen. It may be you have the scope set to deflect the trace off screen to the left or right.

Maybe to start, let us see the scope display with a dot in the center of the display with NOTHING connected. Then connect the sweep x input to the scope. You then need to raise the brightness and/or adjust the scope X channel centering control. Also make sure you start with the highest setting of the v/div control and it would be useful to begin with the X Channel set to AC input.

In the latest picture but I haven’t used it in years and one of the beams is messed up

I can't see any pics here @ work...

will have to wait till later.

But I don't see markers...Penthode showed this setup without a vertical input and he had 5 markers on the horizontal trace. That's what I'm trying to reproduce but there are no markers.

Correct. You will NOT see markers using the setup he outlined using a digital scope. You cannot reproduce it using the HP digital scope using the inhibit technique.

I suggest you try connecting the Z-axis output to the z-axis input on the digital scope. If that doesn't work, you will have to use an analog scope.

Yes, a 465 or 2213 will work. Rotate the timebase on the 2213 to XY

Just any plain old scope with a an X-Y display will work. Is something inhibiting the display? Make sure the scope is not set to trigger.

Without the RF connected you should see a horizintal line trace. The dots will appears when the marker controls are set mid position. Remember if the marker controls are set fully CW or CCW, you will not see the dots. (And CW in this case is Clock Wise!)

Let's look for the sweep line first. What is inhibiting the trace on the scope? If the sweep output of the generator is not reaching the x input of the scope, you should just see a dot in the center of the screen. It may be you have the scope set to deflect the trace off screen to the left or right.

Maybe to start, let us see the scope display with a dot in the center of the display with NOTHING connected. Then connect the sweep x input to the scope. You then need to raise the brightness and/or adjust the scope X channel centering control. Also make sure you start with the highest setting of the v/div control and it would be useful to begin with the X Channel set to AC input.

I have the 3MHz sweep line. What I don’t have are the markers. When I push in the button to select a marker I get a read on the marker Nikki tubes that’s very unstable and unreadable

Correct. You will NOT see markers using the setup he outlined using a digital scope. You cannot reproduce it using the HP digital scope using the inhibit technique.

I suggest you try connecting the Z-axis output to the z-axis input on the digital scope. If that doesn't work, you will have to use an analog scope.

Yes, a 465 or 2213 will work. Rotate the timebase on the 2213 to XY

Z axis input on the scope? Where is that? I have 3 BNC inputs on the scope…X Y and external trigger

external trigger is the z-axis input in XY mode

Here is a picture of the settings on my analog scope and the trace. Those blips on the line, I can't move them or put anymore on the line so I don't think they're markers nor do I know if I have this scope setup correctly other than having it in X-Y mode.

https://imagizer.imageshack.com/v2/800x600q70/924/jWFRWO.jpg
https://imagizer.imageshack.com/v2/800x600q70/922/52BE9Q.jpg

BTW I set the center frequency down to 22.25MHz

I see the x-y inputs to the scope and you have a trace. To confirm the trace sweep is from the HP8601a: the scope is in x-y mode? If you remove the cable to the Ch1 input the trace descends to a dot?

If so, the display you show looks very much like it includes a marker. What have you selected on the 8600a? The control with the button depressed, if you rotate it does the dot move?

Please confirm this before we move on.

I don't see anything hooked to the "Channel 2 or Y" input. (?)

I don't see anything hooked to the "Channel 2 or Y" input. (?)

We haven't gotten to that stage yet. We are first trying to establish we can see the x trace with adjustable markers.

The HP8600a/8601a combo displays markers by briefly interrupting the sweep to produce a bright spot. Chris's scope is displaying that but he doubts it is the marker spot. I would like to prove that it is.

The marker frequency is read from the display of the HP8600a. The whole idea was to be better than beating the a separate RF spot frequency marker with the RF sweep to create a marker blip on the trace. It is supposed to minimize distortion to the swept signal.

I see the x-y inputs to the scope and you have a trace. To confirm the trace sweep is from the HP8601a: the scope is in x-y mode? If you remove the cable to the Ch1 input the trace descends to a dot?

If so, the display you show looks very much like it includes a marker. What have you selected on the 8600a? The control with the button depressed, if you rotate it does the dot move?

Please confirm this before we move on.

correct, I have been playing with my monster analog scope a bit, and if you have it in the right mode, IF you unplug the line you have hooked to CH1, you should get a single non-moving dot on your scope, because ALL the sweep is from an external source, anything else, and it not in the right setting, and it wont work. but if it does show a dot, and then a line when hooked up, then... things a a bit more complicated. :tears:

I SEE IT!! I SEE IT!!

You have Trigger source set to line!
Try chan 1 int,
the way it is now nay be triggering from the line AC input and overriding the drive you are trying to give it.

Trigger is not used in XY mode.

Trigger is not used in XY mode.

You are prob right, but if so, then again, he should get no horizontal activity when the input to CH1 is disconnected.
No input = dot roughly in the center of the oscilloscope
CH1 connected = line sourced from alignment device

And changing the trig source switch (int/line/ext) should have no effect on the dot's movement at all, only input on CH1, if it's working the way it should.

info on scope here.
https://w140.com/tekwiki/images/1/1c/070-3827-00.pdf page 22

I see the x-y inputs to the scope and you have a trace. To confirm the trace sweep is from the HP8601a: the scope is in x-y mode? If you remove the cable to the Ch1 input the trace descends to a dot?

If so, the display you show looks very much like it includes a marker. What have you selected on the 8600a? The control with the button depressed, if you rotate it does the dot move?

Please confirm this before we move on.

Scope is in X-Y mode. Marker dots do not move regardless of what I do to any of the buttons.

correct, I have been playing with my monster analog scope a bit, and if you have it in the right mode, IF you unplug the line you have hooked to CH1, you should get a single non-moving dot on your scope, because ALL the sweep is from an external source, anything else, and it not in the right setting, and it wont work. but if it does show a dot, and then a line when hooked up, then... things a a bit more complicated. :tears:

When I disconnect the X input, I just get a dot. There's sweep and I can vary it with the sweep width adjustment on the 8601. I just don't have any markers.

OK,, this just got really confusing then. :scratch2:
If it's all hooked as shown it should be working.
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208600A%20Operating.pdf
page 11

Given that all cables are OK.
Perhaps the marker is set up in an odd way, Pentode may be able to help there, it's clear that the oscilloscope and the 8601A Generator/Sweeper seem to be set correctly.

I really think there is an issue with the Counter/Marker 8600. Hey, imagine that...I bought a piece of equipment that doesn't work right. How unusual for me.

I really think there is an issue with the Counter/Marker 8600. Hey, imagine that...I bought a piece of equipment that doesn't work right. How unusual for me.

Too soon to say that for sure, debug it with Pentode and others who know the unit and try and work out what the problem is, it may just be set wrong.

All I can say is that it looks as if you are nearly there.

You have ensured the seep is coming from the generator? And the dot you cannot move pressing each and every button? Normally when the button is pressed to select a specific marker, the dot is brighter. I don't think it has been selected from the look of your display. It may be work playing with and cleaning the push button marker switches.

All I can say is that it looks as if you are nearly there.

You have ensured the seep is coming from the generator? And the dot you cannot move pressing each and every button? Normally when the button is pressed to select a specific marker, the dot is brighter. I don't think it has been selected from the look of your display. It may be work playing with and cleaning the push button marker switches.

The thing that suggests to me something is wrong in marker selection is...

When I have the sweeper producing a 3MHz sweep around 50MHz symmetrically, I have the straight line on my scope but...on the display for a marker frequency on the 8600 after say I push the center button, the marker frequency that appears on the frequency display (our favorite Nikki tubes) is not stable. It jumps around very rapidly...too rapid to see so there is no way to select a marker frequency accurately. This is what gives me suspicions it is a hardware issue.

I wanted to do some basic function tests on the 8600. I've disconnected everything between the 8601 and 8600. I set the 8601 to put out a CW of 20MHz and I connected a cable from the 8601 RF out to the 8600 input jack on the front...at the extreme right. I believe this should make the 8600 a basic frequency counter. I get a real-time reading on the 8600 display that changes as I change the frequency on the 8601. This occurs when I have the scope button pushed in on the 8600. When I press the "CW Counter" button on the front of the 8600, I get a frozen readout of the RF frequency that does not change in real-time when I vary the frequency output of the 8601. If I go back to pressing the scope button, I get the real-time frequency read again.

Well if you are sure all is hooked up right, and lines are good, but the unit is at fault.


http://bee.mif.pg.gda.pl/ciasteczkowypotwor/HP/8600A.pdf

here is the BIG manual..

:D

there is a section for "performance tests" in the larger manual that did not seem to be in the smaller one, this may help, and point you in the direction of the fault, if it's not working right.

I wanted to do some basic function tests on the 8600. I've disconnected everything between the 8601 and 8600. I set the 8601 to put out a CW of 20MHz and I connected a cable from the 8601 RF out to the 8600 input jack on the front...at the extreme right. I believe this should make the 8600 a basic frequency counter. I get a real-time reading on the 8600 display that changes as I change the frequency on the 8601. This occurs when I have the scope button pushed in on the 8600. When I press the "CW Counter" button on the front of the 8600, I get a frozen readout of the RF frequency that does not change in real-time when I vary the frequency output of the 8601. If I go back to pressing the scope button, I get the real-time frequency read again.
Unfortunately, the 8600a is not a normal counter. It will not work that way. For it to measure frequency you must reconnect the auxiliary output of the generator. It communicated frequency and the counter input is I believe only able to count lower frequencies.

Please remake the connections as per the diagram and answer the sweep question. We can then proceed from there step by step.

That's right...I forgot. It can only count frequencies to a maximum of 15MHz.

Unfortunately, the 8600a is not a normal counter. It will not work that way. For it to measure frequency you must reconnect the auxiliary output of the generator. It communicated frequency and the counter input is I believe only able to count lower frequencies.

Please remake the connections as per the diagram and answer the sweep question. We can then proceed from there step by step.

Been going over the big manual a bit, it's rather convoluted. :tears:
It looks like it is saying for it to display frequency, it has to plot a curve, with a marker at the top, but I could be reading it wrong.

but there is a lot of info for set up and testing it in there that has to be followed step by step to get it in the right mode it seems.

Difficult to see but it is making markers on the horizontal sweep without the RF input!

https://imagizer.imageshack.com/v2/800x600q70/924/0O74Xp.jpg

The bad news is there was a hardware issue with the 8600. To be honest, after cleaning, switching, spraying etc I did a Shango and picked the front of the instrument up about an inch from the bench and let it bang on the base and viola! The markers appeared. It must be a bad solder joint on one of the boards or a board plug-in not making good contact. Not going to touch it until I get the alignment work setup and then I'll carefully reposition it where it's gonna live. Eventually I'll need to run the issue down.

That's what My High School Electronics Teacher called a "7th Level Adjustment" take id drop it from about 6-7 inches from the table, and SOMETIMES it works! :D

Yeah happy it’s working but I wish I knew how! I’m sure that despite very professional packaging something probably got loosened during shipping. Just spent some time rearranging the Enterprise bridge. I hope I don’t burn out the dilithium crystals!

It looks like I should be having more success than I have...

https://imagizer.imageshack.com/v2/800x600q70/923/RTuzUk.jpg

Excellent news.

I do not know if it is just the photograph but are the nixie elements which are supposed not to light up not being properly extinguished?

Well...they light up with the frequency when a marker button is pushed in. I may have something goin' on here!

https://imagizer.imageshack.com/v2/800x600q70/922/XQsPAF.jpg

That display looks good to me.

It looks as if you are set up now to do some serious aligning!

The thing to remember is that the RCA alignment notes are very complete and accurate. If you cannot get the results expected, it is important to stop and investigate why.

Also I always like to support the bell of the CRT with a small pile of books or a wooden frame I would knock together. Letting it dangle, I fear the CRT is always prone to getting damaged.

Not quite sure about that. I don’t think all is well just yet!
Like Bob, I have the 5” CRT that can be used in place of a 10BP4 installed in the chassis so we’re good there

I’m not so sure this setup in the photo is ready for prime time just yet. The trace on the old style analog scope is very diffuse almost like it’s out of focus. It’s nowhere close to being like the alignment trace you posted for your RCA early color TV in terms of quality and sharpness. One of the 2 channels was always a bit disappointing in the crispness of its display trace.

So maybe this weekend we can troubleshoot this and see if we can solve the display issues? I purchased a working TEKTRONIX 465B analog scope that has been refurbished and calibrated and guaranteed to work as advertised. If my current, old beat up worn analog is having issues as I suspect it is then we can do this on the newer scope when it arrives

IDK if this link will work because the item was purchased by me but it looks like a solid performer.

https://www.ebay.com/itm/176481822852

What volts/div are you using on the y-axis? Could be you are viewing a very low level signal and there is a lot of noise.

What volts/div are you using on the y-axis? Could be you are viewing a very low level signal and there is a lot of noise.

Not in front of it right now but I believe you are right as I needed to up the Y-axis signal quite a bit to get a trace with enough amplitude so I could see a discernible shape. I'm attempting to do the first audio adjustment requiring the sweeper and marker for the 9TC240 and get the discriminator waveform correct.

Did you try increasing the output level of the sweep gen?

Yes I did...no discernable improvement.

Input of a 21.25mc 0.1V (and up) RF signal swept symmetrically 1mc into the grid (Pin 1) of the 2nd sound IF and the scope Y input from the junction of C183 and R215. Generator sweep output to the horizontal scope input. Regardless of the fuzzy signal, I was not able to get the Fig. 15 symmetrical positive/negative trace with adjustment of T-113.

Changing the output level of the sweep gen has no effect on the height of the waveform on the scope? It should have a drastic effect.

Then either the sweep gen isn't working or you have something hooked up wrong.

Does the scope display change if you vary the center frequency? Can you see the markers?

Sorry Bob...I just zoomed in on the picture on my phone. That is at the highest output on the sweep gen. Anything lower and it begins to flatline quickly (if I'm remembering that correctly). I don't think I tried to vary the center frequency when it was hooked up to the TV

Markers are very visible

What cable are you using to inject? Is it the original for the sweep gen? You may need to terminate with 50 or 75 ohm resistor. Without proper termination the generator can't accurately track the output level.

Also, what are you using for the Y input on the scope? A X10 scope probe? Demodulator probe?

The noise could be due to the wideband scope. Does the scope have a lower bandwidth setting to limit below 10MHz? Try clipping a 1nF capacitor across the probe feeding the scope.

What cable are you using to inject? Is it the original for the sweep gen? You may need to terminate with 50 or 75 ohm resistor. Without proper termination the generator can't accurately track the output level.

Also, what are you using for the Y input on the scope? A X10 scope probe? Demodulator probe?

The sweep gen did not come with any cables. Just using a BNC cable hookup to the RF and injected into the IF circuit with signal and a ground alligator clips.

1X setting on scope probe out.

I have RF inject and demod out cables from the EICO that were aftermarket builds by an eBayer who builds probes for all kinds of vintage equipment and his stuff is highly rated as I bought probes for my Heathkit VTVM from him. The issue is the probes do not terminate in male BNC hookups. They are the old style with a central solder spot in the center of a phenolic with a screw in ground. I would need to cut them up and modify them to use them. Not opposed to that since the Eico didn't work well.

Maybe, but he shouldn't need to have RF out at 100% to see something should he?

The noise could be due to the wideband scope. Does the scope have a lower bandwidth setting to limit below 10MHz? Try clipping a 1nF capacitor across the probe feeding the scope.

I don't think so but what do I know about scopes? You're saying put a 102 cap on the scope out signal?

No, he's saying 102 cap from the scope input to ground. You should really have the end of your RF out terminated. Without it, the RF output level meter is meaningless.

Do not use a demod probe. Use a 10X scope probe. You will rarely if ever use a scope probe in anything but X10 mode. It loads down circuits in X1 mode.

Maybe, but he shouldn't need to have RF out at 100% to see something should he?

RF out is at 1 volt. The manual says 0.1V. At 0.1 I get a trace about 2 1/2 grid squares vertical on the scope

No, he's saying 102 cap from the scope input to ground. Oh use x10 scope probe. You don't need a demod probe

I'll try it

Cable type, probe type, lead tress, termination...all this stuff is essential when doing an alignment.

RF out at 1 volt on the meter or did you actually measure the output level on a scope?
1 volt is HUGE by the way. We're usually working in uV or mV volts at this level.

That really helped a lot. Cleared up about 75% of the "fuzziness". Image blanking of course with the camera.

https://imagizer.imageshack.com/v2/800x600q70/924/2I8iPR.jpg

This is clear enough that I can actually see something I can understand. The discriminator response is supposed to look like one cycle of a sine wave with 21.25mc exactly at the Y=0 origin. There's supposed to be 360 kc between the peak and trough of the wave or 180kc on either side of 21.25mc. Those marker points of 21.07mc and 21.43mc are exactly at the high and low peaks. The issue now is no matter what I do to T-113 to adjust, I can't get the curve to come back up to Y=0 after the 21.43mc marker to complete the wave symmetrically. It just sorta tails off.

Cable type, probe type, lead tress, termination...all this stuff is essential when doing an alignment.

RF out at 1 volt on the meter or did you actually measure the output level on a scope?
1 volt is HUGE by the way. We're usually working in uV or mV volts at this level.

Learning a lot here. Thank you for being so generous with your time and knowledge. :king:

I suggest you move on to the other stages of the sound IF and come back to this. If the other stages are off it would effect the discriminator response. I usually do this last or come back to it again for a final touch up.

I suggest you move on to the other stages of the sound IF and come back to this. If the other stages are off it would effect the discriminator response. I usually do this last or come back to it again for a final touch up.

OK I'll play around with it a bit. BTW, the sweep/gen was set for 300mV output and not 1.0 volts. Just trying how to figure out how to read and adjust this.

Just use a low enough level you get a decent waveform on the scope. The reason termination is important is because the sweep gen samples the output to maintain a constant amplitude as it sweeps across frequencies. It's expecting a certain load (usually 50 ohms) for this to work properly.

It would be useful what step in the alignment you are at. I believe it is a KCS28 chassis and the alignment should be the same at the 8T241.

Starting Sunday 9/1 I’m going right back to the start with the VTVM based adjustments on T-113. I’m going to post step by step. Hope it doesn’t get too tedious!

Where it says to inject a signal of 21.25mc at 100mV, can I use the sweep generator in CW mode and use the power meter to set the voltage or will it not do that? I do have another signal generator, one of those old Heathkit generators but I can’t get the signal strength to less than 300mV. This is for nulling out both sides of T-113 using the VTVM.

Where it says to inject a signal of 21.25mc at 100mV, can I use the sweep generator in CW mode and use the power meter to set the voltage or will it not do that? I do have another signal generator, one of those old Heathkit generators but I can’t get the signal strength to less than 300mV. This is for nulling out both sides of T-113 using the VTVM.

Yes the 8601a in CW mode is a fixed frequency signal generator. You use the 8600a to set frequecy and a VTVM or scope to adjust for a maximum or minimum voltage as required.

Let's g thru the alignment step by step. Again, the RCA alignment notes should be followed to the letter and if a result cannot be achieved at a given step, it is either the equipment set up of a fault in the receiver. In either case, it must be correct before you move to the next step.

This is for nulling out both sides of T-113 using the VTVM.

You are not following the instructions correctly. You are supposed to detune the secondary (bottom) then adjust the primary (top) for maximum. Then to proceed to adjust the bottom not for minimum but for zero. The VTVM needle will swing positive and negative. You must adjust for zero.

I do not understand why you want to null out both primary and secondary? That is not how a Foster-Seeley discriminator works.

Yes that’s what I thought. I didn’t have a chance to sit down with it today…family stuff and a 94 year old dad in a geriatric center. Life is pretty complicated these days! Thanks for clarifying what I’m supposed to do in this first step

I guess I don’t know what detune means. What am I looking for on the cram when the signal is injected as stated and I’m looking at DC voltage on the meter? Or am I just way off base?

Cram? VTVM stupid autocorrect

I guess I don’t know what detune means. What am I looking for on the cram when the signal is injected as stated and I’m looking at DC voltage on the meter? Or am I just way off base?

Yes you are looking for a maximum dc. The CW signal is just an unmodulated sinusoidal signal. The discriminator is rectifying it hence dc on the vtvm. It could be a positive maximum or negative maximum with respect to ground. So long as it is maximum.

The s curve will be a positive and negative wrt ground. It will be linear between the two peaks. That is because the discriminator is a frequency to voltage converter.

Yours is a split sound receiver. You must be aware of that because it tunes differently from a later intercarrier sets. When you adjust the fine tuning control, you tune for best sound. You will fine tune the FM sound signal across the s response: as you approach the correct tuning point, the sound will become stronger as you approach the slope of the S, next you will then hit total distortion at the peak or null of the S and then clearest sound when the fm signal is swinging between both peaks. If you tune further you will hit distortion again. So the proper point is between the two distortion points. When the set is properly aligned, the picture should be optimum when you tune for best sound.

Consider what I have said above. If it isn't clear you must question before proceeding with the alignment.

I don't know what it means to "Detune" the T-113 secondary. I know it's the adjustment on the bottom of the transformer can but I don't understand the term detune. Detune how? What am I looking for that indicates the secondary is "detuned"?

As for the next step with injection of the 21.25mc signal at 100mV into the second sound IF grid (V117 pin 1) when I get a DC voltage read I'm trying to peak, we're talking a maximum of around 30mV. Does that sound reasonable?

I'm taking the DC voltage at the intersection of R203 and R204 on T-113 (tab C)

Just turn the slug a few times. You don't need to look at any readings.

Just turn the slug a few times. You don't need to look at any readings.

Either way? So the idea is to take it out of it's previous setting like spinning the tuning pegs on a guitar string just to start the tuning process all over again?

Correct

The reason for detuning is so that you can clearly see the primary peak. Then you proceed to the discriminator zero adjustment. The "null" does not mean minimum. It means zero. The adjustment will swing plus and minus. You want zero. I normally set the vtvm to read zero mid scale so when I adjust the secondary adjustment I can clearly see it swing positive and negative.

Once the discriminator zero adjustment is made, you generally go back to the primary to slightly touch it up to make the discriminator peaks equal amplitude. Then again confirm the discriminator zero adjustment.

The reason for detuning is so that you can clearly see the primary peak. Then you proceed to the discriminator zero adjustment. The "null" does not mean minimum. It means zero. The adjustment will swing plus and minus. You want zero. I normally set the vtvm to read zero mid scale so when I adjust the secondary adjustment I can clearly see it swing positive and negative.

Once the discriminator zero adjustment is made, you generally go back to the primary to slightly touch it up to make the discriminator peaks equal amplitude. Then again confirm the discriminator zero adjustment.

OK the secondary has been detuned. I know multiple photos are annoying but here is what I have setup to go.

Here is my VTVM. To be honest, reading voltages and resistance is about all I have done with this. Peaking is something I haven't done often. The instructions say a 3 volt scale but all I have in that range is 1.5 volts and 5 volts. It's set for the 1.5 volt range. From your instructions, I'm not concerned with values, just with maximum movement on the needle? I have it zeroed to the bottom scale which is dBm.

https://imagizer.imageshack.com/v2/800x600q70/922/7oz0PC.jpg

Instructions say use a probe in series with a 1 meg resistor. My probe has this resistor built into the probe.
https://imagizer.imageshack.com/v2/800x600q70/924/XBPugP.jpg

The generator is set for 21.25mc at 100mv. The meter doesn't show this voltage but I confirmed it on my scope.

https://imagizer.imageshack.com/v2/800x600q70/923/1RU2Iw.jpg

https://imagizer.imageshack.com/v2/800x600q70/923/IwC5j0.jpg

Here are the input and output to VTVM points. Input is to pin #1 V117 and the DC probe is on the dual resistor (R203 and R204) on terminal C on the secondary.

https://imagizer.imageshack.com/v2/800x600q70/922/M7eQCP.jpg

https://imagizer.imageshack.com/v2/800x600q70/924/gD9xMa.jpg

So I guess I'm asking is does this setup look OK? My biggest concern is am I using the VTVM correctly, arbitrarily zeroed to the midpoint of the scale and tuning the primary for maximum deflection to...what, the left or does it not matter?

That looks okay. Signal level may be a little low. The important thing is to not be so low you cannot see the peak or too high where it will overload and result in a false reading and adjustment. I would recommend setting the vtvm to the correct range and then adjust the RF generator level until you get an adequate level to adjust on the meter.

FYI the zero discriminator adjustment is part 2 the first is to set the primary t113 (top) to maximum at 21.25MHz.

The 1.5v range may be too sensitive. I use on my Heath IM-18 the 5 volt range.

Ok will do

Does it matter if the maximum is to the right or left of center...on the VTVM?

No, and you should have your meter zeroed on the left. The only step you zero in the center is nulling the discriminator.
Just flip to + or - DC volts to get it to deflect to the right.

No, and you should have your meter zeroed on the left. The only step you zero in the center is nulling the discriminator.
Just flip to + or - DC volts to get it to deflect to the right.


OK I did that. Sweet spot looks like a 21.25mc input at 68mV and peaked on the 5V VTVM scale at this point. Any movement of the primary adjustment either way results in a lower reading.

https://imagizer.imageshack.com/v2/800x600q70/923/gSfrBR.jpg

Does this sound and look about right?

Ok so once I’m confident I have the primary of the transformer peaked, I then zero the VTVM in the center and take the reading from the new spot (not in front of it right now) adjusting the secondary from the bottom for zero volts. Then go back to the primary setup and maximize it again…then to the bottom again and so forth until everything is stable with no additional adjustments?

Ok so once I’m confident I have the primary of the transformer peaked, I then zero the VTVM in the center and take the reading from the new spot (not in front of it right now) adjusting the secondary from the bottom for zero volts. Then go back to the primary setup and maximize it again…then to the bottom again and so forth until everything is stable with no additional adjustments?

Yes. Typically just go back once and confirm. Then move on the the sound IF amplifier.

But not yet right? I need to do the 1mc sweep around 21.25 (symmetrical) and make sure the response is linear between 21.17 and 21.32 with 21.25 right in the middle correct? I do have that right now on the scope as per alignment instructions. Figure 13

But not yet right? I need to do the 1mc sweep around 21.25 (symmetrical) and make sure the response is linear between 21.17 and 21.32 with 21.25 right in the middle correct? I do have that right now on the scope as per alignment instructions. Figure 13

Yes that is correct! yes you want to ensure it is symmetrical around 21.25MHz

Symmetrical it is but it does not look exactly like the trace in the service information. Don't want to mislead anyone. I don't have all of the signal trace in figure 13 but what's missing from it is the same from the positive end to the negative end. I don't get the first or last 20% of the trace but what I do get on the scope is centered and symmetrical. Putting 21.25mc on the origin (X=0, Y=0) and the appropriate markers on the sweep, they are all symmetrical with respect to zero and almost straight between 21.17 and 21.32 with 21.25mc at the midpoint. IDK if that makes any sense but I'm pretty sure this is OK given what you've said about the relative swings of voltage above and below the midpoint (21.25)

Not to keep pounding this but I figure the more I know the better I'll be able to do this properly. This is from an article by Stuart Seeley and Jack Avins in a 1947 RCA review publication titled "The Ratio Detector" This snip from the paper shows the 350kc sweep around the CW frequency. This is exactly the trace I have on the scope at 100mV.

https://imagizer.imageshack.com/v2/1024x768q70/923/SGHvkq.jpg

Symmetrical it is but it does not look exactly like the trace in the service information. Don't want to mislead anyone. I don't have all of the signal trace in figure 13 but what's missing from it is the same from the positive end to the negative end. I don't get the first or last 20% of the trace but what I do get on the scope is centered and symmetrical. Putting 21.25mc on the origin (X=0, Y=0) and the appropriate markers on the sweep, they are all symmetrical with respect to zero and almost straight between 21.17 and 21.32 with 21.25mc at the midpoint. IDK if that makes any sense but I'm pretty sure this is OK given what you've said about the relative swings of voltage above and below the midpoint (21.25)

Did you try increasing the sweep width on the 8601a generator? It appears that the sweep width is too narrow. Once you have the sweep width wide enough to see the s curve, you can use the adjustable markers to ensure you have the 350kHz between peaks. This is very important.

Not to keep pounding this but I figure the more I know the better I'll be able to do this properly. This is from an article by Stuart Seeley and Jack Avins in a 1947 RCA review publication titled "The Ratio Detector" This snip from the paper shows the 350kc sweep around the CW frequency. This is exactly the trace I have on the scope at 100mV.

https://imagizer.imageshack.com/v2/1024x768q70/923/SGHvkq.jpg

FYI: This is a discussion of the Ratio Detector. That is not what is used in the RCA receiver. The TV uses the Foster-Seeley Discriminator. It lacks the AM limiting function of the Ratio Detector.

You can tell the difference at a glance by looking at the diode polarities in the schematic. The Foster Seely are in the same direction and the Ratio Detector have the pair opposite facing.

Did you try increasing the sweep width on the 8601a generator? It appears that tghe sweep width is too narrow. Once you have the sweep width wide enpough to see the s curve, you can use the adjustible markers to ensure you have the 350kHz between peaks. This is very important.
Yes I did and I could see the reciprocal downturn and upturn of the curves with a broader sweep but this scope is so fuzzy, any wider on the sweep and the trace just trails off. I'm pretty confident in my assessment that the curve peaks are correct at 21.07mc and 21.43mc and equidistant from the 21.25mc frequency. The curve is pretty straight as it gets close to the carrier frequency on both the + and - sides. You know, this is the best assessment I'm capable of doing at this point on my learning curve. Other than having either you or Bob sitting with me and twirling the knobs and moving the slugs, this may have to do. On the practical side, looking at these adjustment screws on the top and bottom of T-113, I can tell they're pretty close to where they were for years looking at the oxidized surface of the screw outside the can and the shiny surface that's just popped through the "nut" part of the can. It's not a nut really. It's metal pressed on the screw threads from all sides. I know this step is very critical to the rest of the process and I will be certain to do more testing with the scope and sweep and research on this type of circuit to have more confidence in saying it's adjusted correctly.

Yes I see that now but it looked to me like this preliminary discussion about maximizing the primary voltage, setting the second voltage to zero and sweeping 350mc symmetrically across 21.25mc at 100mV was close to what the instructions said to do. When I looked up the FS discriminator, several folks pointed to this article as a good read to get a baseline understanding. Anyway, I'll keep at it. Thanks again and again!

I'm concerned about the trace on your scope being fuzzy.
What do you have your volt/div set at?

It should be very sharp and defined. I've never measured the level of the signal I'm putting into a set. I just use the lowest signal that gives me a clear trace.

Even on a super basic, old scope, you should get a clear trace.
https://live.staticflickr.com/8706/16941792327_95465c5927_z.jpg (https://flic.kr/p/rP67BH)

I'm concerned about the trace on your scope being fuzzy.
What do you have your volt/div set at?

It should be very sharp and defined. I've never measured the level of the signal I'm putting into a set. I just use the lowest signal that gives me a clear trace.

Even on a super basic, old scope, you should get a clear trace.
https://live.staticflickr.com/8706/16941792327_95465c5927_z.jpg (https://flic.kr/p/rP67BH)

A super old scope will provide a clearer trace on the basis of lower bandwidth. A lo pass filter feeding the scope should ameliorate the noise.

The other causes of noise are bad grounds, lack of proper shield and electromagnetic/ electrostatic noise in the environment. A test to determine the noise in the environment is to simply remove the scope probe see how much the hanging probe noise is. Then touch the probe hot lead with your finger.

With the probe disconnected and the sensitivity set to 0.1v/div anda x10 probe, I see a 3vp-p sinusoid when I touch the hot lead. when nothing is connected to the probe at the same vertical sensitivity of 0.1/div, I see a straight line.

A super old scope will provide a clearer trace on the basis of lower bandwidth. A lo pass filter feeding the scope should ameliorate the noise.

The other causes of noise are bad grounds, lack of proper shield and electromagnetic/ electrostatic noise in the environment. A test to determine the noise in the environment is to simply remove the scope probe see how much the hanging probe noise is. Then touch the probe hot lead with your finger.

With the probe disconnected and the sensitivity set to 0.1v/div anda x10 probe, I see a 3vp-p sinusoid when I touch the hot lead. when nothing is connected to the probe at the same vertical sensitivity of 0.1/div, I see a straight line.

OK guys...thank you so much. I'm off to teach tonight so I won't be back on this until tomorrow. I think we're getting close.

200mV input of 21.25mc signal. This is swept symmetrically through 1.0mc as the alignment instructions say. The shape of the right side of the curve curve doesn't look like Fig. 13 in the service data but it is sorta symmetrical and the 3 markers are where they are supposed to be I think. The trace should begin ascending back up after the third marker (21.43mc) but it isn't and I don't know if that's important or not. I have the scope probe grounded through a 1000pF capacitor. The fuzzy smearing doesn't appear to be an issue anymore. In person, the line is tighter than it appears in the photo.

https://imagizer.imageshack.com/v2/800x600q70/924/13gYky.jpg

The scope probe must be grounded directly to the chassis. You have it going through a cap?

No, he's saying 102 cap from the scope input to ground. You should really have the end of your RF out terminated. Without it, the RF output level meter is meaningless.

Do not use a demod probe. Use a 10X scope probe. You will rarely if ever use a scope probe in anything but X10 mode. It loads down circuits in X1 mode.

No I do not have the capacitor between the scope probe and the place where I'm supposed to get the scope output. I wouldn't get a signal if I did that right? I grounded the scope input by attaching the scope input to the same point. Is this correct? See below.

https://imagizer.imageshack.com/v2/800x600q70/922/fPsQYH.jpg

The scope probe lead is grounded to the chassis as well

Yes, you absolutely would get a signal if you bet a cap between the scope probe and the circuit you are probing. That's the same as putting your scope in AC coupling mode.

"I grounded the scope input by attaching the scope input to the same point."
I don't understand that statement. You should not be grounding the scope input. I think be are mixing up terms here.

The scope PROBE should always be grounded. That's the black clip. It goes to the chassis. The scope probe tip goes to the test point.

You don't need a 1,000 pF cap anywhere for anything.

You wrote "I have the scope probe grounded through a 1000pF capacitor". That would mean the black clip on the scope probe would be connect to one end of a cap and the other end of the cap would be going to the chassis.

That is not what you show in the picture.

The scope trace should look better than that. Unless it's your camera making it look faint and smeared.

Here's an "S" curve from a similar chassis on a 350MHz bandwidth analog scope with no bandwidth filtering.
https://live.staticflickr.com/65535/53970959506_197c63bf72_o.jpg (https://flic.kr/p/2qeegWA)

Dear god...so embarrassing. I thought we had talked previously talked about using a 1nF cap in this manner. My bad. Yes the probe is grounded through the scope clip to the chassis and the probe is connected to the test point. I'll get rid of the capacitor. I don't know what I'm doing wrong. 10 pages of instruction, mentoring, buying equipment, suggestions, fixes, double checks and triple checks and still crap on the scope. Maybe I'll change the 6AL5 and see if that does anything. The instruction says connect the scope probe to the junction of C183 and R203. Isn't that pin 5 on the 6AL5 or do I have this wrong too?

Assuming that this is not hot chassis, and / or things are isolated, you could try a secondary ground wire to the chassis to the o-scope, don't rely on the probe ground alone, I have to do this at work often, and I have never seen a scope that did not have alt ground points on it that could be used for such things.

Tried that...no change. Maybe the feed into the second sound IF is wrong? Pin 1 of V117? That input from the sweep gen has a ground clip I have attached to the chassis

You do not have crap on your scope. What volts/div is your scope set to? I think it may simply be you need to feed a stronger signal into the scope.
You should also terminate the end of the RF out cable. I assume with 50 ohms. The original RF out cable likely had a termination pod with little alligator clips.

Or maybe there's something wrong with the scope. Does it produce a sharp bright line when there is no signal?

Out of XY mode I have 2 sharp lines for both channels 1 and 2. I cant tell what V/Div I'm using on the horizontal because the scale wheel is broken off of that adjustment. When you say RF termination and 50 ohms, do you mean put a 50ohm resistor between the RF clip lead and pin 1 of V117

Volts/div vertical. RF clip lead and ground.

Volts/div vertical. RF clip lead and ground.

RF clip lead and the RF ground lead? Talk about needing to be led by the hand...RF clip lead and ground...so connect a 50ohm resistor between the RF signal clip lead and the RF ground clip lead?

Yes. Think about it this was. Your RF out is like a radio transmitter. Without a load at the end, the RF is going all over the place including being reflected back into the generator.
Every work on a ham transmitter or hear of a dummy load? You're probably too young to remember token ring computer networks or you'd be all too familiar with termination.

I just solder a 47 ohm resistor between the test clips

Here are some ancient ones.
https://live.staticflickr.com/277/18312494044_c0520ba17e_z.jpg (https://flic.kr/p/tUdjtW)

https://live.staticflickr.com/5164/5233289867_01b1edf9de_z.jpg (https://flic.kr/p/8YrYKD)

Thanks Bob...Patience of Job

The broken scale wheel is an annoyance but by no means a stop, you should be able to work out what the sets are using the other channel, since it's a dual scope, every scope has a calibrate output for the probe, set everything to the calibrated point, and with both channels showing, set the non broken one to any arbitrary input level 5,10, 2v what ever, hook that input to the calibrate probe output, note how many steps it shows on the screen (scale), change to the broken side, switch around till it matches, you have found that setting that the non broken one is set to, mark it with some kind of permanent marker, you now have a known start point to where you can count to the other settings.

I think you have an EICO 369? It has one built into the output lead as shown in this diagram.

Now let's be clear - you will still get RF output without this resistor. You can still do an alignment without this resistor.
However, the get the best results (and keep your generator happy) you should use one. It will also mean your output level meter should be accurate,

Notice there is also a resistor and 1,000 pF capacitor inside the demodulator probe.
That's what Pentode was talking about adding. It's a low pass filter and will help remove noise if you have a fuzzy trace.
I'm not sure based you your scope screenshots if that's really what your trouble is.


https://live.staticflickr.com/65535/53971246931_cb111157c3_z.jpg (https://flic.kr/p/2qefKoc)

I think you have an EICO 369? It has one built into the output lead as shown in this diagram.

Now let's be clear - you will still get RF output without this resistor. You can still do an alignment without this resistor.
However, the get the best results (and keep your generator happy) you should use one. It will also mean your output level meter should be accurate,

Notice there is also a resistor and 1,000 pF capacitor inside the demodulator probe.
That's what Pentode was talking about adding. It's a low pass filter and will help remove noise if you have a fuzzy trace.
I'm not sure based you your scope screenshots if that's really what your trouble is.


https://live.staticflickr.com/65535/53971246931_cb111157c3_z.jpg (https://flic.kr/p/2qefKoc)

I had just pulled out both those probes from the 369! Unfortunately, they have the funky male connector on the end and not the male BNC. I'll have to Amazon some overnight and get them swapped out. New Tektronix 465 coming tomorrow as well so maybe a reboot...(another thread???) would be a good thing to do.

Bob
On the old WO33A you show, is the probe you are using a WG-349A probe?
No demod in it, but is it a form of 10-1 modern day scope probe?

I had just pulled out both those probes from the 369! Unfortunately, they have the funky male connector on the end and not the male BNC. I'll have to Amazon some overnight and get them swapped out. New Tektronix 465 coming tomorrow as well so maybe a reboot...(another thread???) would be a good thing to do.

http://www.smbaker.com/wordpress/wp-content/uploads/2015/12/eico369-unmodified.jpg


Seen them before, not sure what you call those old type RF jacks :O

Bob
On the old WO33A you show, is the probe you are using a WG-349A probe?
No demod in it, but is it a form of 10-1 modern day scope probe?

It's whatever it came with it. I got the scope NiB




Seen them before, not sure what you call those old type RF jacks :O

Amphenol mic jacks is one term

Let's get back to the discriminator response. The results you are getting are poor. The noise with lack of the S- curve means something is wrong.

It is difficult to diagnose via this forum. However the noise and the lack of an S- curve suggests the 6AL5 may not be conducting. Check to see if the tube is lit.

A common fault with this chassis is the 5.1ohm series filament resistor which goes open. Can you check this first?

OK. I'm a bit confused here. I have been following this closely, as I also have sets that can do with alignment. But will NEVER have the money to throw at stuff like the HP 8600 marker/HP 8601 combo mentioned. However, I saw mentioned later in the thread a EICO Model 369 which is a bit confusing, cause I had thought the HP setup was being used :O.

These are also a bit pricey and hard to find, HOWEVER, I do see some EICO Model 368s out there that ARE in my price range that can be updated to a Model 369 w/o too much effort, so, can this be used for alignment of my sets?

There is something fundamentally wrong here because the alignment process should be pretty straight forward. It is however extremely important to try and understand what is happening here.

The HP equipment was not expensive. As I said I shopped around and the total price for the pair I bought was well under $100. As for sets not needing alignment after more than 70 years? Let's put it this way: a proper alignment transforms the quality of the picture and sound. These RCA sets featured full Luma bandwidth. My sets after proper alignment can resolve the resolution wedge of the Indian head test pattern right to the center. Not many sets can do that.

So let's not disparage the process and find out what is wrong. As I said, the discriminator alignment is not working. The noise and the odd response suggests the 6AL5 is not conducting. Can you check the 5.1 ohm resistor to the 6AL5 filament and check the tube is actually lit?

Thanks everyone. I will take all suggestions and report back. Tuesdays and Wednesdays I teach in the evenings so I can’t be in front of the bench. Wish I was. Public school system is producing freshman college students who cannot write or speak!

As i said I ave been looking and to get the same HP combo it would take $400-$500 or more, on evil bay. NOT gonna happen! but can an EICO Model 368 do the job?

As i said I ave been looking and to get the same HP combo it would take $400-$500 or more, on evil bay. NOT gonna happen! but can an EICO Model 368 do the job?

I saw the same on eBay. All I can suggest is be patient. I waited. Both my units were from eBay.

Eico 368 does not do post parker injection and only supports one marker. It's also an entry level device and will require TLC to use. Meaning routine calibration and good understanding how it works and how it should be used.

Eico 368 does not do post parker injection and only supports one marker. It's also an entry level device and will require TLC to use. Meaning routine calibration and good understanding how it works and how it should be used.

but I was referring to this

https://bama.edebris.com/download/eico/368/Electronic-Technician-1969-04-OCR-Page-ALL-combined.pdf

the upgrade 368 - > 369 .

Will the 369 do? or is it also limited?

but I was referring to this

https://bama.edebris.com/download/eico/368/Electronic-Technician-1969-04-OCR-Page-ALL-combined.pdf

the upgrade 368 - > 369 .

Will the 369 do? or is it also limited?

It will work. But the job becomes more complicated because it does not have an accurate marker. You would need some means of calibrating the marker or use a separate marker generator.

The Eico is okay for later cheaper intercarrier sets which only have a couple of traps. The late 40's RCA receivers are as complicated to align as you can get with 6 video if traps and the split sound tuning constraints which means absolute marker accuracy is necessary if you wish to have decent results. The RCA and Dumont were the best and most expensive sets available due to their design.

I did everything I could to get my Eico 369 working correctly including having custom RF out and demod in made and I couldn’t get it to work right but, then again, I can’t get this setup to work right so maybe I’m not the best judge. I’m going to convert the Eico leads to terminate in male BNC connectors so I can use them for this ongoing project. The RF probe has a built in 47ohm resistor.

Aw don't do that. It's only original once. I doubt it's the source of your problem anyway.

Don't use the 1,000pF cap and turn up the RF out. Forget about what level the alignment says to use. I've also asked several times what volts/div you have the vertical at?

What I'm trying to determine is do you have a very weak signal and it's getting swamped by noise. Or are you just not feeding a strong enough signal into the set

Well, I have an offer to get an EICO Model 368 at a rather good price, which will need to be rebuilt anyway, so if I do jump on it, might as well do the 369 update to it at the same time, there is calibration instructions for it as well.
I have till this weekend to decide, (offer expires) :O

They aren't original probes for the unit. There's a seller on eBay who makes custom probes for all kinds of old equipment since for many of them, the accessories have long since separated and have been lost. He made custom DC voltage and resistance probes for my Heathkit VTVM. I think there must be something of a demand for the Eico 369 probes since he offers them as part of his standard "for sale" stock.

Aw don't do that. It's only original once. I doubt it's the source of your problem anyway.

Don't use the 1,000pF cap and turn up the RF out. Forget about what level the alignment says to use. I've also asked several times what volts/div you have the vertical at?

What I'm trying to determine is do you have a very weak signal and it's getting swamped by noise. Or are you just not feeding a strong enough signal into the set

Again, I'm not sitting with the unit at the moment so I'm not 100% sure but deleting the cap, 10X on the scope probe and 250mV of signal strength I still have these results. When I get my new old stock Tektronix setup tonight, I'll get you a spot on read for the vertical V/Div. Previously, I had blasted a 1.0V RF into the TV and was instructed that was a huge signal strength so I started using the reduced recommended voltage.

I did swap out the 6AL5 for 2 other replacement tubes with no change. If it is a filament voltage issue, that wouldn't make a difference so I need to check that out as well and check the filament resistor as Penthode recommended.

.

Have you checked if the 6AL5 is lit?

Have you checked if the 6AL5 is lit?
No not yet. I'll do that this evening

6AL5 is fine. New scope in and working. Got the trace...BUT IT'S BACKWARDS!

https://imagizer.imageshack.com/v2/800x600q70/923/qs2ZI7.jpg

So the other scope was sick?

To ensure we are on the same page, please define backwards. Do you mean the x axis is scanning right to left? If so that suggests a polarity inversion on the x channel input.

And why is part of the trace darker? is the photo accurate to what you see or is there a shutter speed issue? If it a shutter issue, perhaps reducing slightly the scan trace speed will help.

So the other scope was sick?

To ensure we are on the same page, please define backwards. Do you mean the x axis is scanning right to left? If so that suggests a polarity inversion on the x channel input.

And why is part of the trace darker? is the photo accurate to what you see or is there a shutter speed issue? If it a shutter issue, perhaps reducing slightly the scan trace speed will help.

Yes I believe the other scope was sick. This one gave me bright, clean and sharp traces.

By backwards I mean it's like a mirror image left to right like the trace rotated 180 degrees around the Y axis.

The picture being darker on one side is a shutter issue. It's a great trace, crisp, clear and of equal brightness intensity throughout.

BUT...the markers are in the right places so maybe the rotation is with reaspect to the X axis

On a symmetrical trace like this, how do yoiu know if it's the horizontal or vertical that's reversed?

On a symmetrical trace like this, how do yoiu know if it's the horizontal or vertical that's reversed?

By the frequency of the markers. It's rotated 180 degrees around the X axis...my mistake earlier

The 8601a is a ramp waveform sweep to the x axis input. If the trace is backwards, there must be a phase inversion switch on the x channel input at the scope.

Is that an invert button beneath the volts/div control?

And can you reduce the sweep speed slightly on the generator (little knob on the lower right from panel) so that the photos show a bright clear display for us?

And I should add that on late 40's RCA TVs, almost all have the 5.1 ohm series filament resistor to the 6AL5 discriminator. I have restored about a half dozen of these sets and four of the resistors were bad or became bad shortly after coming back to life. So be prepared if you loose sound to first look to see if the 5.1 ohm is bad.

Is that an invert button beneath the volts/div control?

It says waveform off

And can you reduce the sweep speed slightly on the generator (little knob on the lower right from panel) so that the photos show a bright clear display for us?

And I should add that on late 40's RCA TVs, almost all have the 5.1 ohm series filament resistor to the 6AL5 discriminator. I have restored about a half dozen of these sets and four of the resistors were bad or became bad shortly after coming back to life. So be prepared if you loose sound to first look to see if the 5.1 ohm is bad.

I will check the resistor. I tried changing the sweep rate on the 8601 and took a series of photos...they were worse

About as good as I can get

https://imagizer.imageshack.com/v2/800x600q70/922/MaG3qq.jpg

Manipulated the photo a bit

https://imagizer.imageshack.com/v2/800x600q70/924/RTfTnW.jpg

Try increasing now the x gain to fill more horizontally the screen.

Congratulations. That looks much better now.

To invert the x channel so the sweep is correct from left to right, select the Vertical menu and select INV.

Not only is the scope new but I’m using a high quality and new TEKTRONIX probe. That could account for the difference in quality. Are we fairly certain this reversal is a scope setting issue or could the discriminator somehow be tuned to produce this? Does it make sense to replace all the resistors and ceramic caps in this area of the chassis? I know these stone caps rarely fail but you never know. I can’t find anything yet on the scope that suggests the horizontal polarity is being rotated out of phase to this degree.

I did invert it and the trace looks like it’s supposed to but the frequency scale is reversed. They increase right to left

I did invert it and the trace looks like it’s supposed to but the frequency scale is reversed. They increase right to left

I am then confused. If the frequency increase was originally from left to right, then the y axis must be inverted. Try reversing the inversion on the x axis and apply it to the y axis.

The detector in the receiver is often going to invert. It won't make any difference to the operation so long as it is a symetrical S and the slope in the center of the S is linear. It is only the way we are viewing it.

When I restore a set, I replace only what is necessary: electrolytics that fail to restore, paper capacitors that have a high DC potential across where leakage will cause a problem. I leave the resistors until I fire the set up and the analyse the performance. Eg narrow width could be the dropping resistor feeding the horizontal oscillator. I have lots of new old stock carbon composition resistors I replace the originals with.

And I try to wire it as if no one has been there since manufacture. (The only difference is the capacitor appearce between the old paper and newer metal film. Resistors look the same except for the added or improved tolerance band). Even if the resistor is slightly out of tolerance, so long as it does not affect performance, I will leave it.

I know others disagree with my approach, but if the electroytics have not been abused eg powering up the set after decades of in activity, I try to retain the original electrolytics. Of the five pre-1950 RCA televisions in my possession, I have had to replace only two electrolytic cans. The rest survived. I do give the set an extended bench test to confirm all is well and if there is any doubt, I would replace it.

My 1947 RCA 721TS I restored four years ago is used regularly and retains all of it's original electrolytics. I bought the set in around 2015 and the previous owner said the set was retired in about 1960 to his parents attic and had not been powered in 55 years. I carefully and slowly reformed each electrolytic capacitor and replaced only the paper capacitors I deemed necessary before powering up. I don't use series light bulbs or variacs. When the the time comes "wham" on goes the power. I check, recheck and check again everything before the first power and I have never had a set in the last 40 years explode in my face. (I first worked on your chassis in 1969).

Is that an invert button beneath the volts/div control?

Channel invert is accessible through the menu selection button.

https://w140.com/tekwiki/wiki/TAS465
jr

Thanks guys…be back on it tomorrow night! Glad I’m working with more reliable equipment!

Channel invert is accessible through the menu selection button.

jr

Found it in the menu. Trouble was the x channels did not require inversion but the y channel did in order to match the service notes picture.

I know others disagree with my approach, but if the electroytics have not been abused eg powering up the set after decades of in activity, I try to retain the original electrolytics. Of the five pre-1950 RCA televisions in my possession, I have had to replace only two electrolytic cans. The rest survived. I do give the set an extended bench test to confirm all is well and if there is any doubt, I would replace it.

My 1947 RCA 721TS I restored four years ago is used regularly and retains all of it's original electrolytics. I bought the set in around 2015 and the previous owner said the set was retired in about 1960 to his parents attic and had not been powered in 55 years. I carefully and slowly reformed each electrolytic capacitor and replaced only the paper capacitors I deemed necessary before powering up. I don't use series light bulbs or variacs. When the the time comes "wham" on goes the power. I check, recheck and check again everything before the first power and I have never had a set in the last 40 years explode in my face. (I first worked on your chassis in 1969).

I have a 721TS that I restored about 3 years ago that had an original stand. I was owned by one family as well and I bought it from a couple who were retiring and downsizing. One of them told me she remembered the day her father brought the TV home and although it stopped working in the late 1970s, it had remained a fixture in their living room until she inherited it. They cared for it as lovingly as her dad did and I was lucky to get it for around $135! I restored it, not with respect for original parts but with new components. It hasn't been turned on in a couple of years. I'll get back to it one of these days.

I have a 721TS that I restored about 3 years ago that had an original stand. I was owned by one family as well and I bought it from a couple who were retiring and downsizing. One of them told me she remembered the day her father brought the TV home and although it stopped working in the late 1970s, it had remained a fixture in their living room until she inherited it. They cared for it as lovingly as her dad did and I was lucky to get it for around $135! I restored it, not with respect for original parts but with new components. It hasn't been turned on in a couple of years. I'll get back to it one of these days.

That was a great deal for something lovingly preserved! I am very happy with the 721TS as it is relatively compact and is a a good although somewhat archaric performer with split sound and no AGC.

Photo as best as possible but the trace is equally bright all the way through. I did invert the vertical. What do you all think? Is it time to move to the next step?

https://imagizer.imageshack.com/v2/800x600q70/922/Rw5cpn.jpg

Doesn't get better than this...in the shop watching the Eagles' season opener on my Admiral Bakelite Baby!

https://imagizer.imageshack.com/v2/1024x768q70/924/N5Zrpx.jpg

Photo as best as possible but the trace is equally bright all the way through. I did invert the vertical. What do you all think? Is it time to move to the next step?

https://imagizer.imageshack.com/v2/800x600q70/922/Rw5cpn.jpg
Yes looking good. Although you could on the 8601a increase the sweep width a bit (there is a vernier adjustment), then increase the x gain on the scope to get a more complete display.

Then adjust T113 top until you get a symmetrical S curve. Then let's move on!

If we do move on to the adjustment of T-112, I'll need help! I'm confused by the instructions to input a signal and the sweep separately.

I got it...just a change in signal input to V116 pin 1

Can we finish T113 first? You still do not have the display right.

Almost impossible to photograph these. Maybe I'll have to turn the overhead lights off. Anyway, good symmetrical trace adjusting T-112 with 21.25 at the peak. Very low signal input.

https://imagizer.imageshack.com/v2/1024x768q70/924/9x7XEX.jpg

Can we finish T113 first? You still do not have the display right.

What's wrong with it?

Your sweep was too narrow and you could not see the baseline to achieve symmetry.

The x gain is too low and your sweep too narrow on T113 and your latest display.

Just a bit more width so we can see the response skirts.

Better????

https://imagizer.imageshack.com/v2/1024x768q70/923/L4Vc3A.jpg

Now go to the 8601a and increase the sweep width

You may have to go to the next click position and then reduce using the vernier. We want to see more of the waveform skirts left and right.

https://imagizer.imageshack.com/v2/1024x768q70/922/J864g3.jpg

That's better! I wanted to see the left right of the S to see the baseline and symmetry..

However could you ensure the 21.25 marker is set? It now says 21.06.

That's better! I wanted to see the left right of the S to see the baseline and symmetry..

So good to move on to alignment of the sound IF, T-112?

However could you ensure the 21.25 marker is set? It now says 21.06.

Yes it is set right on frequency and the bright dot in the center is the marker. The frequency on the counter is one of the curve apex markers

Yes it is set right on frequency and the bright dot in the center is the marker. The frequency on the counter is one of the curve apex markers
I saw you replied the dot is the apex. So the center dot is 21.25?

Here you go.

https://imagizer.imageshack.com/v2/1024x768q70/922/X85YLA.jpg

I was going to take your word for it. The secondary needs a slight touch up. But thanks! Let's move on...

Oh I so appreciate your adherence to detail in this. Certainty when It concerns what I'm doing remotely and with poor photography requires lots of diligence not to mention my inexperience.

Here's what I have to start the sound IF adjustments. Peak is slightly off, sweep is 3mc.

https://imagizer.imageshack.com/v2/1024x768q70/923/KZsDPQ.jpg

Looks good. Try also keep the x gain up to see more detail.

Looks good. Try also keep the x gain up to see more detail.

Slight touch up on the primary got everything aligned and symmetrical

https://imagizer.imageshack.com/v2/1024x768q70/922/NpDX1F.jpg

Had the horizontal inverted. Corrected it. No change to the trace but now the markers are on the right sides of the center.

Looks good!

You mean...I'm moving on to the Picture IF Trap adjustment???:worried::worried::worried::worried:: worried::worried::worried:

I think that's enough success for one night! Thank you so much my friend for helping me get this far. More to come!

No problem.

However, before proceeding later, I may make a recommendation to safeguard the generator.

I always worry in the event the output of the 8601a if the clip comes loose should accidentally touch the B plus supply in the set, the 200 plus volts may blow up the output hybrid amplifier of the 8601a. To safeguard the generator, I would suggest inserting in series with the generator a 1500pf or thereabouts capacitor. I made up my own lead with the capacitor permanently in series with heat shrink over the capacitor and connection with a croc clip on the other capacitor lead. Just as a safeguard. There is some protection on the output but not to protect you from a 250volt application.

Just a suggestion.

So a 1500pF capacitor on the RF signal out line between the generator and the clip that gets attached to the test signal input in the TV correct? This is to block accidental clip contact with a b+ voltage source in the set from feeding back up the RF out line into the 8601. Have I got that right? Just put the cap in series between the end of the signal wire and the alligator clip that attaches to the tv circuit.

Yes that's it.

Question that has nothing to do with alignment. When I first started this project, I had concerns about voltages and total amp draw of the TV (1.75A vs the >2.0A commonly seen). I got lots of great advice and basically stopped worrying about it as the consensus was running the TV with all new caps would make it work more efficiently hence the lower amp draw.

Not sure why I was inspired to do this but I was wondering if the filament voltage had anything to do with this and a less than optimally bright picture on the CRT. The filament voltage is 5.7V AC and not the standard 6.3V. I understand this is an isolated secondary winding of the power transformer with no other draws loading it down. I took the voltage read on the filaments of the audio output tube. This is a shot in the dark from someone who has no idea if this could be an issue but the only paper caps I haven't replaced yet are the safety caps on the AC line. They are baked, oil smeared domino type caps and I have always had plans to replace them but could they have anything to do with AC voltages in the power transformer?

You don't mind me asking. But what are you using for a voltmeter? If it is the Heath IM-18, when was it last calibrated?

No I’m using a new digital unit from Klein Tools

Something does not seem right. Where and how did you measure the filament voltage? What is the Mains supply voltage?

I pulled the audio output tube and put the meter probes in holes 2 and 7. I’m running it on 117 volts AC through a Sencore isolation transformer

I was working on it from the top of the chassis and not under so I did a quick voltage check

The CRT is dim but has strong emissions on testing. The set only makes a passable picture when the brightness is turned up about half way. Any further up it goes dark and it seems to get bigger before it fades to no light

Ion trap is adjusted to best brightness

All this is with the original 10BP4 but it was behaving the same way with the 5” test CRT

Why are you using an isolation transformer? And did you measure the supply AC with it switched on? As it is on the bench, I'd like to see the supply voltage when on, the rectifier DC to ground, the negative rail (from the transformer center tap) and the filament voltage.

Yes I’ve measured the output before but not during this project. I’ve just always been told that while you work on these old TVs you should use an isolation transformer setup. You’ve probably seen it in some of the photos. It’s the Sencore unit most of these guys use. Are you saying it’s ok to run it on straight 120V line voltage?

It is a transformer set. When working on hot chassis sets, I always use an isolation transformer. On these set? No need.

What you do is replace the AC filter capacitors. The ones from the AC supply in to chassis. Use only 1000v dc capacitors or ones rated for 600v ac. Once replaced use an ohmmeter from each prong to chassis to confirm no problems. The is no resistive leakage here so the reading will be more than 50 Megohms so off the scale of most of your meters. And thats it.

So no on this and other full transformer sets like this, no isolation transformer is needed.

I suspect your isolation transformer is dropping the supply to 95 volts ac.

But put it this way: if th supply is 120vac, I would expect the filaments to be about 6.5v ac. Because it is only copper wire and a fixed transformer ratio, it is impossible to have the low filament voltage you cited unless there is a resistive drop someplace (which will dissipate a lot of heat) or the losses in the isolation transformer are causing the supply to the set droop when on.

Ok that’s great information to have! I have the XY safety caps rated for 600V AC. The caps in the tv are 0.01uF. I have safety caps with a variety of capacitance values. Should I replace the old ones with the same value capacitors?

Also be aware the PR57 output voltage meter is not very accurate. I put mine about 5 volts about 117 to get 117 out with a set drawing a couple amps.

You should be able to go all the way up on the brightness. I wonder if your HV rectifier tube is weak?

Absolutely right on the isolation transformer drop. With no load and the AC output set to 117 volts I turned on the tv. I’ve had it set to the amp scale and not the voltage scale. When the TV came on full power, the transformer output voltage dropped just short of 10 volts

Also be aware the PR57 output voltage meter is not very accurate. I put mine about 5 volts about 117 to get 117 out with a set drawing a couple amps.

You should be able to go all the way up on the brightness. I wonder if your HV rectifier tube is weak?

I had put a NOS 1B3 in it but I can try another. NOS doesn’t mean much when it comes to 70 year old vacuum tubes

It was the transformer. I put it on straight line voltage at 121V AC and the CRT is bright and I've got decent resolution on the multiburst bar sweep

I wish I knew what to do with this stupid iPhone camera to take these images without blanking but I'm happy with the image on the CRT

https://imagizer.imageshack.com/v2/1024x768q70/924/mnjzZz.jpg

That is great.
As far as the camera is concerned, my cell phone camera I have to photograph closer to the CRT to fo the shutter to slow sufficiently to obtain a picture field without the black bar.

Have you finished the sound alignment?

If step 4 aligning T-112 is the last step in the sound alignment, then yes it's complete. The next step, Picture IF and Trap alignment first step is, for me, a "Say What" moment! A potentiometer between pins 5 and 6 of the V107 socket...after removing the tube? Yeah, I need help!

Yeah removing the tube and adding the pot is standard process for this chassis. You just attach the pot where indicated and use it to set the proper bias to the IF amplifiers while doing alignment.
The trap alignment is easy with the HP combo set up. You select CW on the 8601a generator and the 8600a marker. Then as instructed set the frequency on 8601a and the adjust the traps ( and there a lot of them in this set) for a null or minimum on the VTVM.

What kind of potentiometer? A variable resistance pot? In what range? How do you use it in a way that makes connecting it in the sockets secure while you adjust it? Do I need to build some sort of rig/tube base with a pinout?

Also be aware the PR57 output voltage meter is not very accurate. I put mine about 5 volts about 117 to get 117 out with a set drawing a couple amps.

You should be able to go all the way up on the brightness. I wonder if your HV rectifier tube is weak?

So when I set the PR57 to 117v and turn on a tv, yes the voltage drops. It never occurred to me that wouldn’t happen with straight line voltage. So if I’m monitoring voltage, after the tv is on and up to full power I should readjust the voltage back up to 117V?

Yes but also I wouldn't trust the built in meter. Mine is off by about five volts

What kind of potentiometer? A variable resistance pot? In what range? How do you use it in a way that makes connecting it in the sockets secure while you adjust it? Do I need to build some sort of rig/tube base with a pinout?

It is effectively a rheostat or variable resistance. Just wire two leads to the pot wiper and element end and attach it to the pins five and six. I typically take a longish cheap croc clip lead, cut it in two, solder it to a pot and then clip the leads to pins five and six.

It says what it is in the manual doesn't it? 250k or something like that? (I don't have the manual in front of me at the moment).

It is effectively a rheostat or variable resistance. Just wire two leads to the pot wiper and element end and attach it to the pins five and six. I typically take a longish cheap croc clip lead, cut it in two, solder it to a pot and then clip the leads to pins five and six.

I’ll have to look closer for the resistance value. I don’t have any pots that go that high so I’ll need to check the Riders before I order one. The clip lead idea sounds doable. I was thinking of getting fancy and getting a test adapter for the socket wiring the pot to that.