Well I finally got one! The TV I have always wanted. The CTC-5. Traveled all the way to Massachusetts and back home to Florida. By car. It was a 19 HOUR drive! It was well worth it in my opinion. Got the set for $500 with a good rebuilt 21axp22a that tests like new on all three guns. Not to mention the cabinet is in great shape! I have already started work on this set and I have stable HV and great vertical and horizontal sync. I have recapped all boards but the chroma board which is up next. The set is already showing great potential.
I will post new work as it is done.
Here is a photo album with more pictures (will be updated as work continues) http://imgur.com/gallery/9a4Fa/new

Nice, I always liked that model. It reminds me of the CTC-7 Anderson console I had a few years ago, Ed now has it up in Buffalo.

It does look similar to the Anderson!

Sweet! This is the first antique TV I ever saw. I stumbled across Doug Harland's CTC-5 Westcott on Youtube many years ago, and I've wanted one ever since. I'm looking forward to seeing your progress on it!

The hue control won't bring me near the correct colors. Just recapped the chroma board. I remember adjusting a coil in my ctc-7 to adjust the range of color the hue control had. Is this likely the same adjustment for this set?

Cool ! I like the ctc-5 cabinet among the best of old tvs...... Nice small footprint.
Good Luck, mine is still in my storage closet..... Someday..... One winter I'm
going to have all my crap in a row and have time scheduled to work on some
of these sets.....

.

That's looking really good so far! A good buy for the price!

Finished recapping the chroma board. The picture has severe purity issues. Will address that then do a preliminary convergence and get a decent b&w picture first. Then for the color. More to come later.

I can get a decent color picture but after 15 minutes I lose most of my blue screen. I know the blue gun tests awesome. Intermittent connection maybe?

Soon to have that famous Early Roundie "Glorious Lollipop Color".... (grin)

Nice tv set! I also am restoring my CTC5 Westcott, coming soon...

I can get a decent color picture but after 15 minutes I lose most of my blue screen. I know the blue gun tests awesome. Intermittent connection maybe?

Monitor the blue G2 and G1 (color blue color video injection point) voltages before and during the loss of blue. The one that changes is your offender.

Here is what I have now. The picture seems like it could be a lot more brilliant. I cant turn up the color too high or I will not be able to get correct colors. Please excuse the purity issues. Could this picture be improved? It looks a bit better in person.

The luma signal (i.e., the black & white or 'video') component is absent. Only the chroma signal is being displayed.

Could the delay line be causing that?

The most frequent causes of loss of luma are 1. Dirty Service Switch (but I don't believe CTC-5 has a Service Switch) and 2. Heater-cathode short in the CRT.
Try tapping gently on the CRT neck with something like a screwdriver handle. That'll usually show up a H-K short.
Other things can cause loss of luma too, including open delay line.

Looks like I had it in my first picture of the set without the color...

I also suspect the chroma takeoff and 4.5 mc coil may have something to do with it. The crt checks fine with the H-K so I dont think it can be that.

If you have a test pattern generator with a strong variable level video output I'd use it the try injecting video to various points in the monochrome signal chain (use a cap in series with the video lead to prevent DC from damaging the unit unless you know the generator has one built in). Start at the monochrome video output (if injecting at the grid gives you video work towards the detector till you loose it otherwise work towards the CRT till you get video). If you have an audio/RF signal generator you may be able to use that in place of the video generator by finding a frequency that is a multiple of the vertical and or horizontal scan rate...I did that in a pinch once, and it worked well....So well that I ended up playing with different frequencies to see what kinds of patterns I could make. :D

If you have an oscilloscope you can trace the video forward from the detector till you loose it. Best to use a vertical bar gray-scale test pattern for the scope method since it will give you a nice easily recognizable stair stepped pattern between the sync pulses.

Will do

In your screen shot it looks like the chroma level, color sync etc. are good. So turn the color control completely all the way down. Forget about color for now. It's a completely separate system from the luma (B&W video) chain. With the color off, the set should show a normal B&W picture.
The luma chain is what you need to work on.
-----
On a related note, remember that in a tube type color set, luma goes into the CRT via the cathodes; color goes into the CRT via the (G1) grids.

Bad Delay line or last video amplifier. Check the delay line and the connections to it.

The luma signal (i.e., the black & white or 'video') component is absent. Only the chroma signal is being displayed.

He is right ! check the schematic, follow where the video amp is and look
anywhere along the line, don't get stuck on some single part just cause you
know it's name, troubleshoot it along the way.... Contrast control, tube, check
tubes & tube voltages, lose parts, tube sockets, hit stuff and boards with a
nude stick see if it's intermittent, etc. etc....

.

OK the 4.5mc coil was badly out of alignment so I readjusted that with my scope. I think I now have a pretty good picture for a CTC-5 super. Aside from the purity issues it looks pretty good in person. I will do edge purity and a bit of convergence since the convergence already looks good. Then I will take a look at the HOT cathode current and adjust that if needed. Also going to add a fan to the HV cage to keep the fly cool. And then I may be already done with this restoration!

Much improved! Still looks a bit washed out, though. On the video I mentioned earlier, the Westcott had a sharp, rich picture.

I did some reading up on the A version of the 21axp22. The red dag coating was used to prevent internal arcing in the neck of the tube. Does this imply that the original 21ax had arcing issues inside the neck? We're the phosphors on the A version improved over the original?

There are at least 3 flavors of 21AXP22 that I'm aware of:

The earliest ones had the same phosphors as a 15GP22 giving a greenish look to the screen and had normal grey dag on the inside, the chassis they were used with always had series anode resistance to protect the flyback in case of an arc in the CRT. Part number would be 21AXP22.

Next is the same tube, just with improved brightness from different phosphors. This one was used in most of the CTC-4's you see out there unless a replacement was installed, and it's easy to tell because the screen appears white instead of greenish. Part number is still 21AXP22, still all grey dag.

Last version to come out before the glass tubes was the 21AXP22A. This is the one with a white screen and red resistive dag on the inside, which eliminated the need for series anode resistance for arc protection from the previous model. All CTC-5's used this tube and it's compatible with earlier chassis.

The same is NOT true of putting a 21AXP22 (non-A) into a set having a CTC-5 chassis, which has no built in series anode resistance. While it's true it will 'work', the caution there is that without any series anode resistance you run the risk of shorting all HV anode current to ground in the event of a CRT failure. The whole point of series anode resistance is the protect the chassis, without it you blow up more parts when the CRT goes. So if you have a CTC-5 and your CRT has all grey dag, either install some resistance in the anode lead or prepare to replace the flyback if the tube dies.

The red dag doesn't prevent arcing, it merely saves other parts from death should an arc occur.

Checked the delay line. There were two leads coming out of one end and just one lead coming out of the other end. One of the two leads read .1 ohms and the other lead read 830 ohms. The side reading 830 ohms sounds like it could be causing the complete absence of luma. What do you folks think?

Checked the delay line. There were two leads coming out of one end and just one lead coming out of the other end. One of the two leads read .1 ohms and the other lead read 830 ohms. The side reading 830 ohms sounds like it could be causing the complete absence of luma. What do you folks think?

Your latest picture does not show complete absence of luma, although it does look like the brightness control is way too high, washing out the blacks. Do you have the service manual that gives the CRT bias setup procedure?

Regarding your delay line resistance readings, are you measuring in-circuit or out? And exactly where are you connecting the ohmmeter?

The service manual I am reading is the one from the ETF website. I am reading the early set manual. I dont see anything that specifically says CRT bias setup. And I tested the delay line in circuit. I was measuring everything from the end with only one lead on the delay line.

See the setup procedure attached.

Regarding the resistance readings of the delay line in circuit, it is very complicated to tell what they should be because you are measuring everything connected to it. The only way to be sure is to have readings from a good set to compare to.

The alternative is to disconnect the line and see what readings you get of the line by itself. There should be conduction from the input to the output and no conduction from either the input or output to ground.

I'm not sure what the normal resistance is between input and output, but I suspect it will be low, as theoretically the line is supposed to work by a combination of distributed inductance (the coil) and distributed capacitance (the coil is wound on a thin insulator over a ground foil).

Possibly a reasonable test would be to simply by-pass the delay line and observe if contrast is greatly improved? : :scratch2:

Of course the picture would be a little strange looking, as the luminance signal would be slightly ahead of the color signal, but it should give you an indication of the operation of the delay line.

jr

How would I replace the delay line if it might be bad? The setup procedures did not seem to do anything. Maybe something in the contrast circuit could be bad?

Starting to think that the delay line is not the issue here. I can get an OK crisp picture but only with the contrast, color,and brightness turned down pretty far. Only watchable in a dark room. I checked two of the pins on the 12BY7A video output tube (plate and screen grid) and found that both voltages on the pins are off. This must be an issue with a resistor in the 12BY7A portion of the board. I must note I wired in parallel two 1 uf film caps to create a 2uf cap to replace the electrolytic that was there. The schematic calls for a 2 uf cap but the one I removed was an 8 uf. I never found any production changes stating that a 8 uf should be used instead of a 2 uf. Maybe I should try an 8 uf?

If it's any consolation, I have never been satisfied with the luma drive level on my CTC-5. It seems the chroma sections have much more capability. It's on my "some day" list to revisit this issue, but now that it's been brought up, maybe someone else here can comment.

One thought: check the AGC and make sure you have the proper video level at the video detector. Also try substituting video output tubes. In the Magnavox set I had, I found that the output tubes varied quite a bit and you could get more gain out of some than others. I think the luma channel is really pushing to get enough gain out of the final tube.

perhaps a contrast mod would be wise?

perhaps a contrast mod would be wise?

I think it couldn't hurt. Just be careful and don't get the control reversed like I did. It works OK if you do, but max contrast is counterclockwise.

I think it couldn't hurt. Just be careful and don't get the control reversed like I did. It works OK if you do, but max contrast is counterclockwise.
Did you wire the pot up like in a ctc7 or ctc9 or perhaps a different type of mod? Add another video stage, perhaps? :scratch2:

jr

Here's the mod. I posted it in 2008, but it looks like it has disappeared.

Thanks for posting! I guess it looks more like the early ctc7 circuit versions, with the 3900pf cap. The text appears to be correct, but the schematic appears to not show the ground connection for the cold end of the pot/- of the cap/1k resistor.

jr

Installed the contrast mod. I went with a 3300 pf cap instead of a 3900 because it gives a crisper picture. Picture looks PERFECT. I didn't know a super chassis could create such a pretty picture! Almost done here. Need to do edge purity, convergence, and measure the cathode current on the 6CB5A and adjust it if necessary. How does the picture look to all of you? Good color?

Did some work with the convergence. This set is a real pain in the ass to converge but I do like that all the adjustments are on the front panel. Have a blooming issue now. Comes and goes. Not too noticeable but does get annoying.

Looking good. Remember convergence only needs to look good at 10 feet, so don't drive yourself insane if you have one corner that's not as good as the others.

Screenshot looks good now, just don't drive yourself batty with the convergence like Wayne said. It's never perfect, just get it close an enjoy!

Well then I will do an edge purity and check HOT cathode current and install a flyback fan. Will finish up this weekend.

Noticed that the chroma tint drifts while the set is warming up. Maybe I should do a AFC color alignment?

Went ahead and did some color AFC alignment. Tint shifting has become a lot less noticeable and I rarely have to adjust anything now. This picture is looking as good as the CTC-7!

Should I still check the HOT current even though I installed a 120mm fan on a fabricated metal cover I made? The fly gets warm to the touch but not too hot after being on for 45mins to an hour.

Should I still check the HOT current even though I installed a 120mm fan on a fabricated metal cover I made? The fly gets warm to the touch but not too hot after being on for 45mins to an hour.

Does not matter (even if the set does not need the current checked) it should ALWAYS be checked when you get a set and the linearity/efficiency coil adjusted for minimum current.

What current level is considered safe for a CTC-5?

There's no hard and fast number for any set, you adjust for minimum reading on the meter.

What current level is considered safe for a CTC-5?

As miniman said you want min current in operation, BUT there is usually a safe(ish) max that is published in the sam's for most sets (usually in the horizontal adjustment procedure). If over max after warm up assume something is wrong.

As miniman said you want min current in operation, BUT there is usually a safe(ish) max that is published in the sam's for most sets (usually in the horizontal adjustment procedure). If over max after warm up assume something is wrong.

From where do I measure the current? Manual says the h out tube fuse holder is where the current can be measured I hooked up my 27fm and I am not getting anything....

Be sure the probes are connected properly to the meter to measure current. Also remove the H out fuse and put the probes on the fuse connections. You want the lowest current, but it should never go above 210ma. If it is over 200ma I would look for other problems. HO current should always be the first thing you check.

When the HV just comes up I get about 179 ma after about 4 seconds it starts jumping around I go from 400ma to 900ma and it just keeps jumping around... What is going on?

Your meter sucks. This is why I always just read milivolts across a 1 ohm resistor inserted from the cathode pin to ground or wherever, takes the guesswork out. Most of my sets have one permanently installed, in a spot where I don't have to remove the chassis to get at it.

Holding at 230ma. Went to adjust it and the slug is frozen in the coil. How do I free it up without removing the chassis from the cabinet?

If 230 ma. is a correct reading it's gonna cook the H.out tube in short order.:eek: It ain't too easy on the flyback either.

You free the slug by trying to turn it while heating the coil with a heat gun or hair dryer, or if the lin coil wires are reasonably thick and your adventurous you could hook a "D" cell battery across the lin coil and let the battery heat it like I did successfully on my CTC-4. Wax melt is likely what is holding it.

The lowest I can get it is 220ma which is OK according to the service manual. What do you guys think?

I think you can get it lower, but I also think it doesn't matter much on a 5. The flyback primary just doesn't have a low enough DC resistance to make much power (or heat), which is also the same reason it will never draw enough current to make decent HV at the secondary. Run it for a good half hour, then power down and check flyback temp with your hand after HV discharge. My guess, it won't even be warm to the touch. I did everything I could to mine trying to push more out of it: installed a drive control and cranked it to max, installed a HV pot and cranked it to max, put in the strongest testing 5U4 and 3A3 rectifiers I could find, nothing helped at all. Since you can't change the primary resistance in the flyback, the only other thing likely to help is increasing voltage to the circuit. You might try using silicon rectifiers in place of the 5U4's, but I still don't think it would make much difference. The 5 just is what it is, and we have to deal with it.

I think you can get it lower, but I also think it doesn't matter much on a 5. The flyback primary just doesn't have a low enough DC resistance to make much power (or heat), which is also the same reason it will never draw enough current to make decent HV at the secondary. Run it for a good half hour, then power down and check flyback temp with your hand after HV discharge. My guess, it won't even be warm to the touch. I did everything I could to mine trying to push more out of it: installed a drive control and cranked it to max, installed a HV pot and cranked it to max, put in the strongest testing 5U4 and 3A3 rectifiers I could find, nothing helped at all. Since you can't change the primary resistance in the flyback, the only other thing likely to help is increasing voltage to the circuit. You might try using silicon rectifiers in place of the 5U4's, but I still don't think it would make much difference. The 5 just is what it is, and we have to deal with it.
Got it down to 200ma by decreasing the line voltage by 2 volts to 113 or so. Still pushing about 21.45 Kv nice and bright. I think it is ready for service.

Here is the finished product. My camera makes the picture look a bit washed out in some photos. It is perfect in person though. And there is a picture of me with the TV after we just picked it up.

here is the finished product. My camera makes the picture look a bit washed out in some photos. It is perfect in person though. And there is a picture of me with the tv after we just picked it up.

nice!

That's looking pretty good.

Enjoy!

Phil Nelson
Phil's Old Radios
http://antiqqueradio.org/index.html

Looks good ! That's the way I got mine home too !

.

Not quite satisfied with the color temperature. While trying to do a proper temperature setup I ran into some difficulties. The manual says to turn the green and blue background controls 30% up from being at counter clockwise. And to turn the contrast control to the halfway position. I know what all this means but how could I tell where 30% is on the screen controls and where halfway on the contrast control is?

That looks great! It's inspired me to start my ctc9 very soon!

Not quite satisfied with the color temperature. While trying to do a proper temperature setup I ran into some difficulties. The manual says to turn the green and blue background controls 30% up from being at counter clockwise. And to turn the contrast control to the halfway position. I know what all this means but how could I tell where 30% is on the screen controls and where halfway on the contrast control is?

They are asking to set mechanically at a certain fraction of full travel (which should be somewhat less than a full circle max). So, just try the full mechanical range to see how far the control can turn and then set it an estimated halfway or 30% of the way as instructed. These are just starting points to get you somewhere with visible light on the screen.

When our shop entered the color market with the CTC-15, we went to 'RCA School' put on by the distributor, where we learned setup procedure from factory reps. They
had us do the whole procedure with both the blue and green Drives at max . Then as a final touchup, back either one (or both) down a bit to get desired 'temp'. The reps may have been "off the book" regarding the Drives, but that's the way we leart it and always did it.

Or, book procedures on earlier chassies may have been different.

In those screen shots of you CTC-5 running, it looks like the contrast is a mite low.

Did what you suggested old coot. Picture looks a lot better. Only problem is that the chroma hue drifts while the set warms up for 10 minutes then goes away but still very very slowly drifts. The contrast is no longer an issue here. The camera caused the bit of washed outness if you will.

Alright THIS is the finished product. I promise this time. :D

crank that color down its way over saturated.
I think it should be more like this

http://videokarma.org/showpost.php?p=3061728&postcount=224

Alright THIS is the finished product. I promise this time. :D

Tube color TVs are never "finished", as long as they can be powered on there is ALWAYS SOMETHING that you could say needs to be done if you look close enough...

That said Dave likes them a bit too pale, swizzy likes them a bit too saturated, and red is up a bit too high relative to the other primaries.

Dave's is the correct saturation, the picture is just too blue.

But to all of you with these old TVs, let me admonish you,

PLEASE!! PLEASE!!!

One word!

Doilies!!!

Dave's is the correct saturation, the picture is just too blue.

But to all of you with these old TVs, let me admonish you,

PLEASE!! PLEASE!!!

One word!

Doilies!!!

:lmao: Doilies are for old ladies! If you want to protect the finish of the cabinet top get a piece of glass cut to match the size and shape of the top and glue some small thin felt pads to the side of the glass that will be resting on the cabinet (one at each corner)....It is much better at preventing scratches and water marks, was used on fine furniture of the period, and looks 300% cooler.

I have noticed that the hue of the colors shift over time while I am watching the set. I find myself having to adjust the hue control pretty often. I thought I heard somewhere that this was a problem with the CTC-5 even back in the 50's. Is this true? What causes this?

Try tapping the burst amplifier tube with something like a screwdriver handle, while watching the display in a mirror.

BTW, a restored vintage TV is never 'finished'. It will always be a "work in progress". :)

Pentode section on the 6an8 burst amp tested borderline. Swapped it out for a better testing one. Helped a bit. Slowed down the rate of change of the hue. Still having to readjust the hue control a bit. What would cause this? I need to get this sorted out before the Super Bowl airs.

When you say "hue", do flesh tones tones drift toward green or purple? Or does the tint of the overall raster drift?

Flesh tones are considered the standard for setting the mid point of the hue control (sometimes called tint control).

Hue (Tint) drift can be due to one of the many cost cutting experiments in the CTC-5 Super chassis. They used burst injection to lock the local oscillator, rather than a phase-locked loop (PLL) with a phase detector and reactance tube. A PLL (as used in the Deluxe chassis and all subsequent chassis) can drive the static phase offset near to zero if it has sufficient loop gain, but the injection locked oscillator is more at the mercy of the oscillator drift with temperature, depending on the "Q" of the circuit and the injection level. So, increasing the burst injection level may improve things.

Years later, Norm Parker at Motorola analyzed the requirements for an injection lock circuit to perform as well as a PLL, and it was successfully used in some Motorola designs.

AGC was not set properly. Turned that up to max and the picture looks BEAUTIFUL. No more tint/hue drift. Looks almost like my CTC-7! :banana:

The 3.58 MHz circuit on the CTC-5 looks a lot like the one in the GE Portacolor and some of the full sized GE color sets.

Increasing the AGC would most likely increase the burst which would help stabilize the 3.58 MHz oscillator.

I noticed that on red colored objects there is a slight magenta glow on the border of the object not too noticeable but still a bit irritating. How do I adjust the flesh tones and get rid of that magenta glow that borders red objects?

I noticed that on red colored objects there is a slight magenta glow on the border of the object not too noticeable but still a bit irritating. How do I adjust the flesh tones and get rid of that magenta glow that borders red objects?

If you look closely you will probably see a slight greenish border on the opposite edge of the red objects. This is caused by phase distortion in the color signal and can be affected by IF alignment (especially the sound trap) and/or chroma bandpass alignment. Unless it is really bad, it may not be worth trying to redo the alignment, as you likely will find it's as good as possible already.

Here is a video of the set. https://www.youtube.com/watch?v=9W3kZNQPxbY
It looks a lot better in person since my camera isnt the best for recording. Cant seem to get decent lighting in the room either.

Nice work dude. Glad you changed your avatar. The old one was frankly a bit off-putting and could make a person less inclined to wanna participate in the thread.

I just watched the video on YouTube, that looks great, good job!

And a BIG thanks to all for the help they provided in helping me get this beautiful set running! :yes: Glad I was able to do more by myself with this restoration unlike my CTC-7 restoration. I'm starting to get the hang of this stuff.

Hey now, that is looking good!

Very impressive. All you need now is a TV lamp facing the back walls, then you can turn the room lights off and enjoy that great picture. But it looks pretty darn good even in that bright room lighting. :thmbsp:

Your TV looks great! Excellent picture for a set that was made sixty years ago (the CTC5 Westcott was made the year I was born).

I don't see a converter box or a VCR/DVD anywhere near the TV. Is that Bonanza episode off the air or cable? :scratch2:

Keep up the good work. These old TVs deserve much better than to be sent to a landfill, and this one obviously won't be.

Thanks a bunch everyone! To reply to jeffhs question, the set is receiving a wired signal from a BT modulator. I can get all the stations provided by my cable company. The modulator is hooked up to my cable box. To be honest, my CTC-5 is producing a better picture than my CTC-7! :D

I figured as much, that you might have been using an RF modulator fed by a cable box. Do you have an in-house type of system similar to the one Kamakiri (Tim) in Buffalo uses for his antique TVs? Since Orlando only has three VHF network TV stations (not counting PBS, Fox, et al.), you wouldn't need that many modulators to build a good local distribution system. I think Tim only uses one and changes the input signal at the modulator, depending on what channel he wants to watch. The modulator's output is on channel 9 in his installation, but since Orlando has a local channel 9 any modulator you use would have to output to some other VHF channel.

Yes I do have a home broadcasting system. With plenty of power to reach the whole house. I had it wired temporarily but now I get everything off the rabbit ears! I use only one modulator to do the job.

Found the original house where this TV came from. Interestingly enough, the house was finished in 1956, the same year this set was manufactured. The set belonged to Mr. Vahram Bagian. Mr. Bagian passed in 1995. He must have been a pretty wealthy man to own this set back in 1956! http://www.realtor.com/realestateandhomes-detail/54-Dartmouth-Rd_Cranston_RI_02920_M48576-54870

I have noticed that when I am watching the set and a picture with a lot of white light comes on the whole screen has a shade of green to it, once the white light goes away the green tint goes away. I remember reading that the 21AXP22's phosphors gave everything a greenish tint. Is this the same with the A version? Or is this occurrence circuit related?

Sounds like the green screen is up too high, or you need to turn down the brightness.

This effect has to be electrical, not the phosphors.
I have never heard of the phosphors giving everything a greenish tint.

However, the usual white balance for sets for decades was on the cyan side ("9300K + 27 MPCD") due to the dimness of the red phosphor and a desire not to overdrive the red gun too much. (This was not true of the very earliest sets such as the CT-100, as they were supposed to be set to illuminant C [daylight white] even though this meant pushing the red gun extremely hard compared to the green and blue.)

By the way, I suspect that CT-100 as used in the home varied greatly, as servicemen had no instruments to tell them when they had achieved the correct white balance. Grayscale tracking (whites and grays being the same color) is much easier to judge by eye than the actual color of those whites and grays.

Your greenish tint is definitely electrical in nature. That said, the earliest 21AXP22s, when not in use, do have an ever so slight green tint, just like a 15GP22, 15HP22, or 19VP22. Perhaps it was discussion of the appearance of the tubes when not in use that SwizzyMan was reading?

There are at least 3 flavors of 21AXP22 that I'm aware of:

The earliest ones had the same phosphors as a 15GP22 giving a greenish look to the screen and had normal grey dag on the inside, the chassis they were used with always had series anode resistance to protect the flyback in case of an arc in the CRT. Part number would be 21AXP22.

Next is the same tube, just with improved brightness from different phosphors. This one was used in most of the CTC-4's you see out there unless a replacement was installed, and it's easy to tell because the screen appears white instead of greenish. Part number is still 21AXP22, still all grey dag.

Last version to come out before the glass tubes was the 21AXP22A. This is the one with a white screen and red resistive dag on the inside, which eliminated the need for series anode resistance for arc protection from the previous model. All CTC-5's used this tube and it's compatible with earlier chassis.

The same is NOT true of putting a 21AXP22 (non-A) into a set having a CTC-5 chassis, which has no built in series anode resistance. While it's true it will 'work', the caution there is that without any series anode resistance you run the risk of shorting all HV anode current to ground in the event of a CRT failure. The whole point of series anode resistance is the protect the chassis, without it you blow up more parts when the CRT goes. So if you have a CTC-5 and your CRT has all grey dag, either install some resistance in the anode lead or prepare to replace the flyback if the tube dies.

The red dag doesn't prevent arcing, it merely saves other parts from death should an arc occur.
My bad, I interpreted this post wrong. I thought the greenish tint was a picture related effect. Not just the color of the phosphors. Also I know know that the A version of the 21ax didn't even have that same phosphor.

I am currently solving a horizontal issue with this set. I have since fixed this but it seems the tuner and IF circuits have gone out of whack. Ive tried all adjustments and tubes. What I would like to do since this TV will soon be in a cabin in Minnesota where over the air and cable is hard to find is to see if it is simple to inject a composite signal into the video and sound amp to bypass the tuner and IF. Is this possible by just connecting a direct video source or will I have to build a preamp for this set too?

I have the same problem with my CTC5. The emission on the 21AXP22A is okay. Advancing the brightness affects grey scale. At lower brightness the greyscale is not bad.

The root problem may be the design of the final luma stage. Compared with the CTC7 upward, the anode current at the quiescent point of the CTC5 appears too high at cart cutoff. I earlier was investigating means reducing anode current quiescent point by shifting the CRT cutoff point.

I looked at this a couple of years ago and put it aside. Now that I know the problem isn't unique to my CTC5, I am going to revisit this. I would be curious if any of you have thoughts on this. I haven't substituted the 21AXP22A and am wondering despite the emission being okay that perhaps the guns aren't tracking properly?

I recommend modifying the CTC-5 video output stage to the CTC-7 configuration.

http://www.videokarma.org/showthread.php?t=256638&highlight=ctc-5+video+output+modification&page=2

I recommend modifying the CTC-5 video output stage to the CTC-7 configuration.

http://www.videokarma.org/showthread.php?t=256638&highlight=ctc-5+video+output+modification&page=2

I had already done this awhile back. And I do agree that it vastly improves gray scale and overall contrast and picture quality. I was able to inject a composite video source to G1 of the video amp and the picture is stellar now.

I recommend modifying the CTC-5 video output stage to the CTC-7 configuration.

http://www.videokarma.org/showthread.php?t=256638&highlight=ctc-5+video+output+modification&page=2

I remember the post. Boy the five years swiftly passed.

I ended up modifying the cathode circuit on the 12BY7 because of the blooming problem. But the green cast at high brightness remained.

I think there is more to do because to drive the CRT to conduct, the 12BY7 current remains too high. If I recall correctly, the 12BY7 control grid bias needs to increase (greater minus). Comparing the CTC5 to the CTC7 or CTC9 should reveal the difference.

After about 1 hour I lose horizontal sync... which I thought I fixed. After checking back on the horizontal board, I found I did not replace one cap (C606?). Tracing everything in front of it makes it seem like it is a very critical cap. Perhaps the cap drifts as it gets warmer considering its proximity to the 6CG7? Does this seem like a critical cap to you guys? By the way it is the only original component left on the board besides the waveform coil.

Yes, critical - determines horizontal frequency in combination with the coil (cut off at the top of your image). Replace with the same type / temperature coefficient.

Yes, critical - determines horizontal frequency in combination with the coil (cut off at the top of your image). Replace with the same type / temperature coefficient.

Thanks for the clarification. After I get that replaced I need to take some shots of the screen. Direct injecting a composite signal works pretty well with a 5.

Here are some obligatory Oz shots from the 5 before I lost sync. Not pleased with how the camera made these out, but it gives you an idea. Picture is not as bright, but a lot more crisp and clear than displayed on camera. This is taken with a composite video signal injected into the video amp. Not too shabby. :yes:

It looks like your camera didn't focus exactly on the screen. Other than that, the pictures are great. You've got better vertical linearity on yours than I have on mine.

Great, could be focused better.

Color level looks a bit high. When skin tones start to glow, look neon, look tan when their not I know to back down the color level a bit. Great picture aside from that.

Color level looks a bit high. When skin tones start to glow, look neon, look tan when their not I know to back down the color level a bit. Great picture aside from that.

Well... I do like my colors saturated :D I'll post some better pictures tonight once I fix the horizontal problem. I was in a rush to take the photos before the horizontal went off.

I remember a few customers back in the day who deliberately ran the color wide open. Their attitude was "I'm paying for a color set, so I want all the color it'll make." :headscrat

I used to roll the vertical hold till the customer told me which picture looked the best. LOL

Ok NOW the horizontal is fixed. I fooled with the camera setting a bit and was able to get a darker picture and cant get the camera to focus correctly, but still...the picture is so much better in person. Thanks to Phil Nelson for the A/V input box idea! This TV is ready to move up north.

There have been these faint vertical lines all across the screen and I have been trying to just ignore it but it is driving me nuts. It goes away when the chroma is turned off so it has to be chroma related interference. Anyone know what these are and how I get rid of them?

There have been these faint vertical lines all across the screen and I have been trying to just ignore it but it is driving me nuts. It goes away when the chroma is turned off so it has to be chroma related interference. Anyone know what these are and how I get rid of them?

I presume they are stationary? Do they vary in intensity with the color control setting? Can you see them when you have a picture on? Do they move left and right with the picture (or move differently than the picture) when you turn the H hold control a bit?

I presume they are stationary? Do they vary in intensity with the color control setting? Can you see them when you have a picture on? Do they move left and right with the picture (or move differently than the picture) when you turn the H hold control a bit?

Completely static. More visible when brightness is turned up. They dont move and they only go away when color is turned off. They also go away when there is no signal being injected. I have hooked it up to a cable box and a dvd player and both had the lines. Also move with the horizontal hold.

Well, 'tis a puzzlement to me. The only thing I see near the switch (which opens B+ to the bandpass amp) is a 6800 ohm and 0.1 uF bypass. It's a wild guess, but you might check those. Also make sure the grounds on the chroma board are solid.

Everything else in the chroma section is running with chroma on or off, so it's hard to see how it could be there.

Well, 'tis a puzzlement to me. The only thing I see near the switch (which opens B+ to the bandpass amp) is a 6800 ohm and 0.1 uF bypass. It's a wild guess, but you might check those. Also make sure the grounds on the chroma board are solid.

Everything else in the chroma section is running with chroma on or off, so it's hard to see how it could be there.

Hmm. I will investigate further...

I was wrong...

Well, 'tis a puzzlement to me. The only thing I see near the switch (which opens B+ to the bandpass amp) is a 6800 ohm and 0.1 uF bypass. It's a wild guess, but you might check those. Also make sure the grounds on the chroma board are solid.

Everything else in the chroma section is running with chroma on or off, so it's hard to see how it could be there.Resistor and capacitor check fine and the grounds are all solid. I am at a loss.

Trying to figure out what could couple something at that frequency to the CRT.

Some straws to grasp at:
Does it change when you adjust the color killer control?
Maybe check the caps (especially .01 or larger) and other stuff in the color killer section?

Killer control has no effect. All caps on the chroma board have been replaced so I dont think it is that..

Well, I'm stumped. I don't mean to be insulting, but have you double checked the values of the bypass capacitors? Other than that, it's time to put a scope on the CRT leads, and if you can see it, trace it back to the source.

Well, I'm stumped. I don't mean to be insulting, but have you double checked the values of the bypass capacitors? Other than that, it's time to put a scope on the CRT leads, and if you can see it, trace it back to the source.

I will try that. Oh and the values are all correct. I may just try and deal with it as it won't be used all that much. I wonder if it is a problem with the fact that I am injecting a composite video source? This never showed up until I modified the set to accept composite inputs.

Of course, any modification is suspect, but how in the world would it come and go with the color switch?

Of course, any modification is suspect, but how in the world would it come and go with the color switch?

I really have no idea. At first I thought it was shielding related on the coax cable, but I have since got a properly shielded and grounded cable so It cant be that. I think I might just cut my losses and live with it. :scratch2: