Last fall I posted a whole bunch of pictures from a local antique shop packed with vintage TVs and radios. I stumbled across TheNixer's classified ad for a bakelite Admiral 24A12 about the same time and hooked them up. He got the itch for another set, looked through my pictures, and this time picked up a 1950 Motorola 19K1 AKA 'The Van Dyke'.

Here's an original ad on tvhistory.tv (http://www.tvhistory.tv/1950-Motorola-Brochure.JPG)

Since it's only a couple miles from me and I've never had the chance to work on a set like this before, I volunteered my services to get it running again.
http://farm3.static.flickr.com/2540/3799643964_4662037575_b.jpg

The cabinet is in rough shape like every set at that shop. Someone there really liked to stack heavy crap on the set and gouge into them. The doors and sides are in much better shape. The door pulls are missing though. Does anyone out there have the same set or know what pulls are appropriate ? I'm only going to be working on the chassis. I hope someone else can do a nice job on that cabinet.
http://farm5.static.flickr.com/4024/4710276260_4d29c26f1d_b.jpg

http://farm5.static.flickr.com/4056/4710271424_4ff0462dda_b.jpg

The insides are in much better condition. I was a little concerned about the 19AP4 when I saw the damaged base, but it tests very strong. It's a factory rebuilt CRT with an 'S' stamped on the neck. I've never work with such a large CRT so am being extra careful. I plan on using a little 5AXP4 during the restoration.

Only a fragment of the back remains.
http://farm5.static.flickr.com/4009/4710271174_cf4d8cc8c6_b.jpg

Dual speakers and integral antenna
http://farm5.static.flickr.com/4021/4710274870_0f0f8342fa_b.jpg

Only two screws were left holding the chassis in :eek: That's why I always remove chassis and picture tubes for transportation if possible.
http://farm5.static.flickr.com/4012/4710272566_37ca66ab45_b.jpg

http://farm5.static.flickr.com/4012/4710276746_9098933e2f_b.jpg

I kinda liked that Moto set when I saw it in those tv shop pictures-the knobs are pretty neat, plus you get to work on that cool giant crt. Just avoid temptation and DO NOT give that metal crt a big hug while it is powered on, okay?

I've had it hope for a couple days now. Here are some more details.

First off I was concerned about the damaged CRT base, but it turns out the tube is just fine. That's really good, I've heard these are few and far between.

The widowmaker. I'm not sure what they mean by "insulating coating". Seems like just glass to me :scratch2:
http://farm5.static.flickr.com/4027/4710277678_59be0b8e86_b.jpg

http://farm2.static.flickr.com/1302/4709886351_a1dfc494ce_b.jpg

The base reads 'factory rebuilt'. Anyone know what the "S" on the neck means ?
http://farm5.static.flickr.com/4009/4709886525_b080bf6dd2_b.jpg

It's good :banana:
http://farm5.static.flickr.com/4057/4709886889_7e433ed1eb_b.jpg

A little size comparison. 5AXP4, 19AP4 and 10BP4. I've never work with such a large CRT before!
http://farm5.static.flickr.com/4048/4709887247_0e8fbf4b6d_b.jpg

Here's the chassis. It appears to be all original.
http://farm5.static.flickr.com/4035/4711026942_5b1d8eb13b_b.jpg

The tuner is quite a piece of work
http://farm5.static.flickr.com/4070/4711027234_e735ebc679_b.jpg

There's a crazy mix of tube brands and about 40% are weak or bad. I bet this set saw a lot of use.
http://farm5.static.flickr.com/4013/4710388511_6895bbe1f5_b.jpg

I can't wait to see those orange knobs light up again :)
http://farm5.static.flickr.com/4067/4712374081_7ae0eec945_b.jpg

I kinda liked that Moto set when I saw it in those tv shop pictures-the knobs are pretty neat, plus you get to work on that cool giant crt. Just avoid temptation and DO NOT give that metal crt a big hug while it is powered on, okay?

Roger that - don't hug the jug :yikes: http://www.jawaspot.com/smilies/shocking.gif http://www.jawaspot.com/smilies/spooky/tombstone.gif

The tuner is quite a piece of work

Can't really see how it works . . . wafers?

Phil

Can't really see how it works . . . wafers?

Phil

Yes, it appears so. What I'm not sure about is the hole in the chassis for each channel. There's an arm with a hole in it sticking out the the selector shaft. The hole lines up over the selected channel. Perhaps it's just an aid for aligning the coil ?

I was finally able to get back to my e-mail this weekend and found two e-mails from Tom. Wow is he a nice guy! He really helped me out with the details of this set. Here are the photos he provided. I can't tell if it's spelled VanDyke or VanDyck. Either way, it's one great looking set.

Bob, thank you for all the photos and attention you've already given the set. It's all much appreciated, thank you.

what is the game plan on that CRT socket? leave and use as is, replace it, or try to build it up somehow? I assume no hurry on what to do until the set is closer to working.

Some manufacturers coated that glass portion of the CRT with some sort of insulating paint, beyond me as to why. I didn't think glass could be inproved upon as an insulator. The pic is of a 16GP4 that was coated.

what is the game plan on that CRT socket? leave and use as is, replace it, or try to build it up somehow? I assume no hurry on what to do until the set is closer to working.

Initially, I was going to remove the remains of the existing socket and replace it. Possibly with a donor from a dud tube.

Now that I've inspected it closer, I think I'll try to build it up with something like 2-part epoxy. All 5 pins and the center key are in good shape. So is the entire circumference of the end of the base.

Reading all the warnings on that CRT are making me a little nervous of messing around with it.

I fired up a more accurate tester and went through all the tubes. I was amazed to find 13/22 tubes are bad. Either failing on transconductance, gas or grid leak! Even both the 6AL5s are really dead - almost no emission. Typically, I find one or two bad and a few weak tubes.

http://farm5.static.flickr.com/4058/4716144067_8f6f7828b5_b.jpg

All the crucial tubes are good though - some relatively new. Like the 6CD6 HOT, both paralleled 5U4s, 6W4 damper and 1B3 HV rectifier. I wonder if that was enough to produce some sort of image or sound and the owner kept running it into the ground ?

In a few radios, I have found tubes that looked pretty dead on a tester but still performed surprisingly well. You can think of various scenarios where someone might play a TV to death as long it made sound. Older person with poor vision, can't see the picture anyway. Uncle Joe listens to ballgames while working in the shop. Family gets new TV, but lets the kids have this in the basement to watch cartoons . . . .

Phil

I was finally able to get back to my e-mail this weekend and found two e-mails from Tom. Wow is he a nice guy! He really helped me out with the details of this set. Here are the photos he provided. I can't tell if it's spelled VanDyke or VanDyck. Either way, it's one great looking set.

Bob, thank you for all the photos and attention you've already given the set. It's all much appreciated, thank you.

Excellent! Tom is responsible for pointing me to this forum a while back :)


"...2 control knobs on front panel are all that are needed for normal operation..."

Ha! Pull off those two 'simple' controls and you'll find all the other adjustments lurking ;)
http://farm2.static.flickr.com/1249/4723212050_9410834dc1_b.jpg

Cool that the tuner has UHF capabilities. I counted 15 positions when I rotated it. If we're really lucky, it has the right parts to pick up some of the few remaining analog UHF broadcasts in our area.
I really hope I won't have any need to go poking around in there.
(click for hi-res version)
http://farm2.static.flickr.com/1358/4722561649_f90998c38f.jpg (http://farm2.static.flickr.com/1358/4722561649_9f489327f1_o.jpg)

That's a nice looking set. I have faith in your refinishing skills, I bet it turns out great!

Some manufacturers coated that glass portion of the CRT with some sort of insulating paint, beyond me as to why. I didn't think glass could be inproved upon as an insulator. The pic is of a 16GP4 that was coated.

Interesting. That portion on this CRT seems to have maybe a hint of old coating. Otherwise, just glass. Maybe they removed it during the rebuild process ?

I haven't run into anything like this before. It appears to be a huge non-polarized capacitor, but the rating is strange. 3VNP 1.0 ohm 60 Hz. Would that be 3 volts non-polarized with an impedance of 1 ohm @ 60 Hz ?

I plugged 60 Hz and 1 ohm impedance into this site (http://www.cvs1.uklinux.net/cgi-bin/calculators/cap_imp.cgi) and came up with 2.65258 mF (about 2,650 uF) :headscrat:

Any thoughts on what to use for a replacement ?

Mouser has some 2,200uF non-polarized caps (http://www.mouser.com/Passive-Components/Capacitors/Aluminum-Electrolytic-Capacitors/Aluminum-Electrolytic-Capacitors-Leaded/_/N-75hqw?P=1z0yoh9Z1z0wqut). Maybe that's close enough ?

It's C4 in the schematic.
http://www.bobandersen.com/images/motorola%2019K1/19K1%20cap-01.jpg

http://www.bobandersen.com/images/motorola%2019K1/19K1%20cap-02.jpg

http://www.bobandersen.com/images/motorola%2019K1/19K1%20cap-03.jpg

That's certainly what it seems to be. I'd think the 2.2 mF caps would be close enough. Probably well within the tolerance specs.

John

This is a situation where a cheap cap checker would come in handy. You can test for unknown values simply by checking where the eye tube closes on the dial scale. All that aside, that has to be the most bizarre method of labeling a cap I have ever seen.

This is a situation where a cheap cap checker would come in handy. You can test for unknown values simply by checking where the eye tube closes on the dial scale. All that aside, that has to be the most bizarre method of labeling a cap I have ever seen.

I do have a couple vintage RC bridges and will try them out. The ranges don't go anywhere near 2,600 uF though.

The parts from Mouser and a bunch of NOS tubes have arrived. Now the fun can begin :D

http://farm5.static.flickr.com/4118/4749502707_4181dd7aef_b.jpg

OK, finally back to the 19K1.

First up, a little cleaning. Luckily, the dust and dirt comes off easily with a soft brush. I followed that up with a rag and a little mineral spirits.
http://farm5.static.flickr.com/4080/4874053465_263d780469_z.jpg

http://farm5.static.flickr.com/4116/4874053703_4d2a721ea6_z.jpg

That's better. I really like that copper plating - not a speck of rust to deal with.
http://farm5.static.flickr.com/4115/4874054017_4fc0ba3b39_b.jpg

The flyback looks to be in excellent condition :thmbsp:
http://farm5.static.flickr.com/4082/4874663006_c07a885f09_z.jpg

Only a couple issues so far. One, a crude electrolytic repair. A wire to the right was cut, the ends stripped and the capacitor lead spliced in. I think I'll replace the whole wire and restuff the electrolytic can.
http://farm5.static.flickr.com/4136/4874147415_7e7927be03.jpg

Two, the yoke & focus coil plug and socket are damaged. I posted in the classified section for a replacement. Plan B is to replace it with a more conventional octal plug & socket.
http://farm5.static.flickr.com/4114/4874663438_5a5a8e0368_z.jpg

Otherwise, just loads of capacitors to replace. The wire-wound sand power resistors are in miserable condition too.

Dah-Yum, I'd be tempted to leave it outta its case...Dat's PURTY !!!

I have those octal plugs if you need one. They're actually battery plugs, using a pilot hole instead of a key--they were used in AB battery packs.

I found some more damage and crude repairs around the horizontal output tube. The replacement resistor fell off when I touched it due to some very poor soldering. The socket is in bad shape too. Pin 8 is broken off and I need to solder a capacitor to it. It might be best to replace it and all the surrounding components :scratch2:
http://farm5.static.flickr.com/4115/4877168522_2e4c4b6187_z.jpg

http://farm5.static.flickr.com/4140/4876559033_e7911262b0_z.jpg

I also noticed that the Sams for this chassis shows two doorknob capacitors with a resistor between (PI filter). I've only got one. Maybe another crappy repair job ?
http://farm5.static.flickr.com/4082/4874663006_c07a885f09_z.jpg

Dah-Yum, I'd be tempted to leave it outta its case...Dat's PURTY !!!

Yeah, but someone would probably get a real charge out of the 19AP4!

John

Dah-Yum, I'd be tempted to leave it outta its case...Dat's PURTY !!!

The cabinet is actually still back in the antique shop waiting for Nixer to pick it up. He's over your way in Tennessee. I'm only going to restore the chassis and somehow get it over to him.

I've seen you mention some folks that restore cabinets in other posts. Maybe they could fix up this one :scratch2:

I have those octal plugs if you need one. They're actually battery plugs, using a pilot hole instead of a key--they were used in AB battery packs.

Oh yeah, they do look like battery plugs. PM Sent.

Yeah, but someone would probably get a real charge out of the 19AP4!

John

Ouch - for sure. Here's the itty-bitty little 5AXP4 I'm using while restoring it.
http://farm5.static.flickr.com/4080/4867511469_e0b1b767b8_z.jpg

Will the 5AXP4 handle the HV of a 19" tube?
Does that set use a doubler circuit for the HV?

I tried one in a 21" rectangular set and it arced inside from too much juice, the rectangular test tube (8YP4?) worked OK though.

Good question. Nope, no doubler.

According to this handy website (http://www.bunkerofdoom.com/tubes/syl59/htmls/crt.htm) we have the following.

CRT, Typical, Max
19AP4, 14 kV, 16 kV
5AXP4, 14 kV, 19 kV
8YP4, 16 kV, 22 kV

I'm a little surprised. I though the 19AP4 would be a little higher than that. I need to rig up an anode cap, but otherwise should be OK.

I'll find out for sure soon I hope :D

I've been making steady progress in between other projects.

First off, I found where that second doorknob capacitor should be. I think I can dig up another good one from another set. Meanwhile, I'll just stick with this one.
http://farm5.static.flickr.com/4141/4889826668_1497cd5da4_z.jpg

I've replaced the power resistors and electrolytics and most of the paper caps.
http://farm5.static.flickr.com/4134/4889274509_180c546f51_b.jpg

Time to do a little power up test with no tubes. No smoke and the transformer voltages look good.
http://farm5.static.flickr.com/4139/4889827216_673d434632_z.jpg

One of the control lights lit up, but I think the other is burned out.
http://farm5.static.flickr.com/4118/4889231997_02b8f95c12_z.jpg

Next, I popped in a few tubes including one of the paralleled 5U4 rectifiers and slowly cranked up the variac.
http://farm5.static.flickr.com/4093/4889827860_596440b285_z.jpg

All the voltages looked good, but I detected a nasty smell after a few minutes. A little sniffing located this fried capacitor. Time for a little more recaping :yes: All told, things are looking very good for a first power up.
http://farm5.static.flickr.com/4076/4889828170_616fddfeb4_z.jpg

Very nice progress on that set!

Thanks. I hate the first power up after some major work. I'm always bracing for a cap to pop in my face. So far it's never happened though - just some occasional smoke :D

I've finished all the recapping and resistor checking except for the HOT area.
http://farm5.static.flickr.com/4136/4896664593_5b2c59b15f_b.jpg

These old sand power resistors were especially crappy.
http://farm5.static.flickr.com/4121/4896664785_5fcd07ea24_z.jpg

That leaves this corner to deal with. I've cleaned out most of the debris and smoky residue. I was able to replace the damaged pin #8 fairly easily so no need to replace the whole socket. I found no less than 4 cut wires associated with the HOT circuit so there's no way this set had a picture.
http://farm5.static.flickr.com/4095/4896664949_aab6844f84_b.jpg

http://farm5.static.flickr.com/4134/4898830755_2cf63cd573_z.jpg

Even the fuse holder is broken :no:
http://farm5.static.flickr.com/4135/4899423488_4b90be3065_z.jpg

Perhaps someone gave up on the repairs. I was expecting to find an open coil, but so far so good.

I also just received replacements for the damaged yoke & focus coil plug from some helpful forum members.
http://farm5.static.flickr.com/4100/4899422888_1098cfdc96_z.jpg




I won't be long before I can try a full power up.

Mine (I've got the console!) is on my bench - the horizontal section's giving me fits and it syncs like crap :( hopefully i'll get it sorted out this fall.

The knob on the lever is the fine tuning adujstment, for when the cover's off. It's a weird set, that's for sure...

(And yes, a 25L6 with a step up auto XFMR for the vert output. Like I said, it's a weird set...)

Yeah, it's a weird one alright. I'm in the process of rebuild the whole horizontal output circuit. I hope to fire it up again in a day or two.

Luckily, the oddball valued 400pF mica cap is still good. Every other component needed to be replaced.
http://farm5.static.flickr.com/4074/4904137918_20956ed3e6_z.jpg

Here's that burnt up corner all rebuilt. I used a flameproof metal oxide resistor so hopefully no more fires.
http://farm5.static.flickr.com/4116/4903548279_ed611d6f8a_b.jpg

Speaking of fires, looks like the yoke connector got cooked pretty good too.
http://farm5.static.flickr.com/4134/4903548605_fdacee06bc_z.jpg

The focus coil leads were deteriorating so I reinforced them with heatshrink tubing.
http://farm5.static.flickr.com/4073/4907156280_a0ebccd71f_z.jpg

http://farm5.static.flickr.com/4095/4907156456_2c4eba4e22_z.jpg

The horizontal yoke leads were even worse. Basically everything to do with the horizontal on this set has been mutilated :tears: So I threaded some new cloth covered wires up into the yoke. I also found that the two 560 ohm resistors were 760 and 810 and replaced them.
http://farm5.static.flickr.com/4116/4907156578_8b2ce2b764_z.jpg

http://farm5.static.flickr.com/4081/4906568437_fba1c00d9b_z.jpg

Now, I could finally rebuild that plug. I was able to polish off most of the gunk from the metal shroud.
http://farm5.static.flickr.com/4080/4906568657_0252f5290d_z.jpg

http://farm5.static.flickr.com/4137/4907157278_c99ac16665_b.jpg

I'm going to try another power up tonight.

The Flyback looks a little cooked on the one side, or is it just black from static attracted dust? Hopefully it wasn't the cause of the meltdown.

It is darker on one side. I think the culprit was the missing doorknob capacitor though. It would have been right next to the darkened area. I'll find out soon enough.

Nuts. There's still something burning up in that corner even with the HO tube pulled.

None of the components are getting hot though. I think it's either the tube socket or the wiring.

I'm tempted to leave it on until I can definitely see some smoke to pinpoint it, but am afraid of burning out something.

Perhaps the terminal strip is charred/arcing?:scratch2:
jr

Perhaps the terminal strip is charred/arcing?:scratch2:
jr

That's a great idea!

I unlaced the wiring harness and separated the wiring, but that didn't make any difference. I don't think it's the tube socket either. That leaves the terminal strip or the stuff on the top of the chassis (horizontal width coil and flyback).

It turns out I was looking in the wrong area. With the chassis on it's side the stink was rising from further below and collecting in the corner. At times like this I wish I had one of those heat sensitive cameras.
Here's one of the culprits. It's a 470 ohm cathode resistor on the 25L6 vertical output tube. I really hope the vertical output transformer is OK.
I still haven't replaced the weird 1 ohm @ 60Hz vertical output capacitor either so it's a possibility too.
http://farm5.static.flickr.com/4076/4909587174_2e76c8f8ff_z.jpg

With that fried open, I let the set run a little longer and saw signs of life inside the HV cage. The 1B3 filament was glowing nicely.
I figure that's a good sign that the hor. tube and flyback are doing something useful.
http://farm5.static.flickr.com/4082/4908990469_2f8596c7e0_z.jpg

Finally, I found this 1K resistor getting toasty. It should have about 30 volts across it, but I'm measuring 100 ! Time for more checking.
http://farm5.static.flickr.com/4123/4908990649_095edd6629_z.jpg

I think I'm getting close. The 470 ohm resistor was getting cooked due to a really bad 6SN7.
Those short indicators are lit up like a Christmas tree!
http://farm5.static.flickr.com/4139/4910530279_5fe23e7ffd_z.jpg

It seems that the other resistor is cooking because one of the new electrolytics has failed. Time to dig up a replacement.

I'm really glad I didn't glue the cans back on :yes:

Hmmm. Now that I think about it, it's the same cap that was crudely repaired long ago. I'd better double check that wiring.
http://farm5.static.flickr.com/4136/4874147415_7e7927be03.jpg

Wow Bob, this one's a real adventure!

The suspense is killing me,
Keep the updates coming. :yes:

You got it!

I was wrong about which capacitor was hot. It was actually the cathode bypass across the 470 ohm resistor that burnt up previously. I've replaced that and have had the set running for about 15 minutes with no signs of any smoke or overheating. The main supply voltages look good too. I checked all the resistances using the Sams reference. They're all good. Now that the set seems stable, I'll check all the other voltages too.

No picture. I'm getting about 9kV at the CRT. It should be more like 14kV. I tweaked the hor. drive, size, linearity etc. but no change.

Also, no sound at all :( I need to take a break and go pick up a new toy. More later.

I've finally got some signs of life out of this beast. I had hooked up one end of this coupling capacitor wrong. That was preventing the final video amp stage, sync circuits and audio amp from getting a signal.
http://farm5.static.flickr.com/4102/4916911985_d087b2f06f_z.jpg

Here's the output from the 6AS5 cathode follower final video amp stage.
http://farm5.static.flickr.com/4073/4916912451_8ea39e9acf_z.jpg

Output from 6V6 audio amp.
http://farm5.static.flickr.com/4093/4917514154_f7995f8c4a_z.jpg

The horizontal drive signal at the 6CD6G HOT looks OK. Still no picture though and the HV is a bit low. I'm going to check the damper tube, flyback and doorknob capacitor.
http://farm5.static.flickr.com/4094/4917513254_c52aa0de98_z.jpg

The vertical oscilliator is running at 84 Hz and the amplitude is half of what it should be. I need to so some more checking there too.
http://farm5.static.flickr.com/4100/4916914007_1b447b0334_z.jpg

Since your HV is low you might try it with a 10 or 12" tube and see what happens.

Is that voltage taken without the CRT installed or with? Perhaps the metal cone is leaking to ground somewhere.

I'm getting about 9KV with the little 5AXP4. I figure I should be getting some sort of image. I'll check the voltages on the CRT cathode and grids.

Doh! I thought you were using the 19" tube for some reason.

I have another dumb suggestion, is the heater lit on the test tube?

I've chased my tail a few times looking for something else only to find i had a dirty CRT socket.

Could the doorknob cap be leaking HV, shunting it to ground? I once had a tv with low HV, it turns out the chassis was leaking HV to a metal rail that was part of the table it was sitting on! I measured about 9kv on the lead, and the table rail read about 1 kv.

Another possibility to explore-is that the proper flyback in the set? With all the hacked repairs someone was doing on the hv section, they may have been trying to put in a different flyback (hence the single doorknob cap-like they were trying to emulate the circuit the replacement fly came from?)

Doh! I thought you were using the 19" tube for some reason.

I have another dumb suggestion, is the heater lit on the test tube?

I've chased my tail a few times looking for something else only to find i had a dirty CRT socket.

Yeah, it is - I wish it was that simple :D

Could the doorknob cap be leaking HV, shunting it to ground? I once had a tv with low HV, it turns out the chassis was leaking HV to a metal rail that was part of the table it was sitting on! I measured about 9kv on the lead, and the table rail read about 1 kv.

Another possibility to explore-is that the proper flyback in the set? With all the hacked repairs someone was doing on the hv section, they may have been trying to put in a different flyback (hence the single doorknob cap-like they were trying to emulate the circuit the replacement fly came from?)

Good call. I hadn't checked that before. It's a Thordarson FLY-40 which is actually the correct replacement for the original Motorola #24C792691.

I'll fire up my EICO 944 flyback & yoke tester and check it out. Might as well check the yoke too while I'm at it.
http://farm5.static.flickr.com/4135/4918697418_16ae9bd923_z.jpg

Here's another look at the darkened area Eric noticed earlier. It looks like there may have been some arcing in the past.
http://farm5.static.flickr.com/4097/4918697862_54b7b09f68_z.jpg

I think I can pull some doorknob caps out of my Admiral 19A15S. Someone replaced the old 6KV paper caps with several of them :rolleyes: I've been meaning to replace them with some nice ASC plastic HV caps. Might as well do it now.
http://farm5.static.flickr.com/4120/4918727400_f6ce2f3d2f_z.jpg

Well, I tested the flyback, yoke plus all the coils and transformers. They all check out OK, except for one tap on the flyback. It should be about 0.8 ohms and I'm getting around 12 which seems odd. I'd expect a bad winding to be either open or have a lower reading if there are any shorts. The EICO indicates that the fly is good though. Maybe the FLY-40 is a little different than the original Motorola ?

I also swapped out the doorknob cap. I fired the set back up and still only had 9 kv. I gave the horizontal lock a few clockwise turns and was able to get it up to 12 kv, but horrible high pitched squeals were coming from the flyback so I backed off. Still no image at all. I checked the voltages at the CRT pins - they're fine.

Before I called it a night I swapped out the 5AXP4 for an 8XP4 just for the heck of it. At last, a faint glimmer of life :thmbsp:
http://farm5.static.flickr.com/4075/4918827351_6a24d75874_z.jpg

I had to crank the focus control all the way which got me thinking maybe the focus coil could be having a bigger effect than I expected. These little test CRTs are auto-focus so don't need one anyway. I physically moved the focus coil around and got a much brighter trace!
http://farm5.static.flickr.com/4137/4919425682_f30f8be1db_z.jpg

Just to make sure the 5AXP4 is OK, I put it back in. I never figured a focus coil position could have that much of an effect! (Yeah, I know that's not the safest HV anode lead :o)
http://farm5.static.flickr.com/4093/4919425810_76f95578a7_z.jpg

Which leaves me with a nice bright trace with no horizontal at all. The width control barely has any effect.
So how is it possible for the flyback to put out HV when there's no horizontal deflection :scratch2: There is a mica cap inside on the horizontal winding inside the yoke. I'll check that tomorrow.

I finally found the problem - a bad horizontal yoke connection. :banana: The HV is up to about 14 kv now.

Here are the first images I got using the rectangular 8XP4. First, using a B&K 1077B which is in need of an overhaul. Next, a low power analog broadcast picked up with rabbit ears.
http://farm5.static.flickr.com/4140/4921692264_747d5047e4.jpg http://farm5.static.flickr.com/4075/4921096267_ded3ffc4d8.jpg

I'm getting some weird clipping so I switched back to the round 5AXP4 and did some tweaking.
http://farm5.static.flickr.com/4137/4921096591_4c2b60cefb.jpg

Almost every control is crammed into one corner. It's convenient, but a little tough when you have big hands.
http://farm5.static.flickr.com/4093/4921869734_f695d6df80_z.jpg

Next, I fired up a Leader test pattern generator. The RF output on it is too weak to produce a decent picture so I fed it into a BT modulator. It's not just his set - the Leader RF is just too weak for any set I've tried it on.

Here are the alignment, convergence and multi-burst patterns. I'll hold off on making an more adjustments until the 19AP4 has been installed.
http://farm5.static.flickr.com/4141/4921096897_0e4b9ab7a2.jpg http://farm5.static.flickr.com/4098/4921693596_edea096b06.jpg http://farm5.static.flickr.com/4074/4921694050_6cffeaa71f.jpg

Finally, I hooked up a DTV convertor box. No sound, but I was expecting that. I have a couple of these Access HD DTA1010 boxes and get very weak or no sound on most of my vintage sets. One solution I've used is to feed the composite output from the converter into a BT modulator.
http://farm5.static.flickr.com/4081/4921694528_9eef454596_z.jpg

I'm going to clean up some temporary repairs and clear off the workbench before remounting that 19AP4.

Its alive..... ITS ALLIIIIIIIIiiiive!!! :D

Holy short circuit Batman, it's working!!! :yes:

Great job Bob! This one looked like a real challenge that turned out to be totally worth the effort:yes: I can't wait to see it back in the cabinet and done!

Its alive..... ITS ALLIIIIIIIIiiiive!!! :D
Muwahahahaha....

Holy short circuit Batman, it's working!!! :yes:
Short circuit indeed between the horizontal winding and focus coil.

Great job Bob! This one looked like a real challenge that turned out to be totally worth the effort:yes: I can't wait to see it back in the cabinet and done!

Thansk! Me too. I'm still not sure how that's going to happen though. I think the cabinet is still somewhere in Illinois. I just have the chassis and picture tube. Somehow they need to be brought together and reassembled at the sets owner's (Nixer) place in Tennessee :scratch2:

As I recall the cabinet was pretty beat up, is it being repaired too?

As I recall the cabinet was pretty beat up, is it being repaired too?

Yes, last I heard.
"I’ve actually talked to Sandy about Jim Obermeyer before and I’ll definitely be taking the cabinet there."

I'm really curious to see what a pro can do with it. I'm guessing the top needs to be re-veneered ? Just about everything in that darn antique shop it came from had some cabinet damage.

That was pretty fast detective work!

I have an Access also and it produces weak sound and awful picture via RF even on modern sets. Works great with a BT though.

That horizontal something coil looks like a real pain to adjust.

I'm anxiously awaiting to hear how the professional refinishing goes.

John

That's the "Horizontal Size" control and is very much a pain to get at. Once this chassis is back in the cabinet, all the adjustments will be even tougher to get at. If you look back at the start of this thread, there's an original ad where they promote the idea that only two controls are needed. We'll see about that.

Mine (I've got the console!) is on my bench - the horizontal section's giving me fits and it syncs like crap :( hopefully i'll get it sorted out this fall.

The knob on the lever is the fine tuning adujstment, for when the cover's off. It's a weird set, that's for sure...

(And yes, a 25L6 with a step up auto XFMR for the vert output. Like I said, it's a weird set...)

Adjusting the hor. lock really helps with the sync on this set.

I took a closer look at the channel selector and still don't get the fine tuning. It looks to me like the only adjustment is the tuning slug for each channel. That level with a hole in it just acts as a guide for an adjustment tool. Is that what the service manual means by a fine tuning control :dunno:
http://farm5.static.flickr.com/4119/4925778318_399b9ca1af_z.jpg

I added a second HV cap and a carbon comp 470K resistor to form a PI filter like the schematic shows. I used rounded solder blobs and it seems to work OK. No arcing so far. I was able to get most of the dark crud off the flyback too. That red splattered stuff is high voltage insulating "paint" applied during some repair long ago.
http://farm5.static.flickr.com/4139/4924175221_d7690801f3_z.jpg

This seemed to produce a brighter, crisper picture, but two dark lines appeared on the left. I cranked the hor. drive all the way down (clockwise). That mostly got rid of them but the brightness suffered. I tried a couple different 6W4s, but that didn't make much difference. Also, the horizontal width coil is warm - not sure if that's normal. Perhaps I should remove that second HV cap after all :scratch2:
http://www.bobandersen.com/images/motorola%2019K1/screen02-01.jpg http://www.bobandersen.com/images/motorola%2019K1/screen02-02.jpg

http://www.bobandersen.com/images/motorola%2019K1/screen02-03.jpg http://www.bobandersen.com/images/motorola%2019K1/screen02-04.jpg

I decided to try out the 19AP4.
http://farm5.static.flickr.com/4095/4926998727_fa33a99c2f.jpg http://farm5.static.flickr.com/4116/4927595960_f5959c9516.jpg

That's a little disappointing - just a faint smudge. I guess 12kv won't cut it. The Sams doesn't mention the HV value, but I found a schematic in a Wallace Telaide that shows 17 kv.
http://farm5.static.flickr.com/4100/4927596234_9d00ac4199.jpg

I've contacted Moyers to see if they have a Motorola 24C792691 or Merit HVO-6 replacement. I'll do some more checking in the meantime.

In your last post you said the picture tube was a 19KP4. I can't find a data sheet for that number, yet earlier pictures show a 19AP4A which is a standard tube. If it's really a 19AP4A that your testing, did you forget the ion trap? That's an easy thing to overlook.

Ralph S

Nice catch! I meant 19AP4. And, yes, I completely forgot about the trap magnet :stupid: You get spoiled using the little test CRTs which don't need them.

After adding the ion trap magnet and a whole lot of tweaking to it, the centering magnets, focus coil, etc. I got these images. The brightness is cranked all the way up and the hor. drive adjusted for the least noticeable dark bar on the left. Too bad Sams doesn't include any directions for adjusting the controls.

It's a little disconcerting feeling all my arm hairs tingle when I reach for a control :yikes:
http://farm5.static.flickr.com/4116/4927887672_2696cee0f8.jpg http://farm5.static.flickr.com/4121/4927888102_851b71ca6b.jpg http://farm5.static.flickr.com/4094/4927292517_d450233d87.jpg

Hmmm. Looks like it works!

Yep - just needs more HV and a few bits need to be repaired like a broken fuse holder and loose lamp socket. Another batch of parts arrives Friday.

Hey, that's looking really good! Seeing that big CRT from the side, it really dwarfs the chassis in comparison. Kinda scary! :para:

What do you suppose is causing those dark vertical lines?

Thanks. It sure is scary. I'm used to working with CRTs half that size not to mention that most of the outer surface is at 12,000 volts!

I have those dark lines to some extent on a few of my sets. They can be caused by a bad damper tube or too much horizontal drive from what I've read. I imagine there are several other components that could be off or miss-adjusted that cause them.

Looks promising. Be careful around that thing!

Re the lines on the left side, if all else fails, read up on Barkhausen oscillations. I actually had that problem once. Even if it's not the cause, just reading about the topic makes you feel smarter :)

Phil Nelson

Looks promising. Be careful around that thing!

Re the lines on the left side, if all else fails, read up on Barkhausen oscillations. I actually had that problem once. Even if it's not the cause, just reading about the topic makes you feel smarter :)

Phil Nelson

I'll be removing that big CRT while I tinker with the set some more. I wanted to make sure it was really good and see if the problems I saw on the little CRT would persist.

I saw that trick on your site with the magnet in the HV cage. I waved a magnet around this 6CD6 tube, but it had no effect. Oh well, there are still plenty of other components to tinker with in the horizontal circuitry.

Sure, I'd check obvious things first. For what it's worth, the lines in my Halli T-67 were cured by substituting horizontal output tubes. One of my books also mentions trying a circular magnet (such as an old ion trap magnet) around that tube.

Phil

It test really good in my Hickok, but I've seen plenty of comments that the only way to really test it is to try it in a set. I don't have any other 6CD6s on hand so I picked up a couple on eBay.

Shoot, I have a bunch of those all you need to do is ask! 6DQ5's too.

Shoot, I have a bunch of those all you need to do is ask! 6DQ5's too.

Oh well. I'll keep you in mind for the future. I got two of them plus a 19BG6 for $0.99.

I've tried everything I can think of and the HV just won't get up above 12kv. The voltages and waveforms on the 6CD6 seem reasonable.


swapping out the 6CD6 with a couple other 6CD6s
swapping out the 6W4 with other 6W4s, 6AX4s and 6AU4s
double checking all the associated components
swapping out the doorknob capacitor


On the positive side, the picture remained unchanged after any of those swaps. I even put some of the tubes that were originally in this set that tested weak or bad and it kept playing just fine. This must be one well designed set.

That leaves me with the flyback. It's tests OK with my EICO 944 and I've had the set playing for a couple hours so I think it is good, but maybe the Thordarson FLY-40 isn't a good substitute for this particular set ?

Here's a portion of the schematic with the resistance values and what I'm actually measuring. That 10.2 vs. 0.6 is the one that's got me concerned. Now that I think about it, that could explain why the horizontal size coil is getting hot. A larger resistance on the tap would mean a higher potential I would think. So that coil would have too much voltage across it.
http://www.bobandersen.com/images/motorola%2019K1/flyback.jpg


Unfortunately, I don't have any replacements for it and struck out with Moyers. Does anyone have any of these flybacks ? Even if someone can just measure the resistance on a FLY-40 it would be helpful.

Motorola 24C792691
Thordarson FLY-40
Merit HVO-6

I do have these flys on hand. Maybe one of them is close enough to try :scratch2:
FLY-49
FLY-51
FLY-55
FLY-58
FLY-59
FLY-81

A Stancor A-8130 "universal" flyback is on the way. While skimming a Wallace Telaide for Zenith 1947-1953, I came across this section on Barkhausen oscillation. I think I'll try suggestion 5 if the new flyback doesn't work any better.

This oscillation usually appears on the picture tube screen as one or several dark vertical lines and is most prevalent under weak signal conditions. One of the following suggestions can be used to correct the condition:

1. Turn the Horizontal Drive Control to a point where the lines disappear. The Width Control should then be adjusted to obtain proper width.

2. Replace the 6BG6G horizontal output tube. It must be noted that a tube which produces a Barkhausen oscillation in one receiver may be entirely satisfactory in another.

3. Mount and adjust a small magnet on the 6BG6G tube until the oscillation is removed.

4. In some early receivers, the 6BG6G cathode was by-passed with a 40 Mid electrolytic capacitor. Remove the cathode lead from this capacitor and connect it to the 20 Mid unused capacitor which is directly adjacent to the 40 Mid unit.

5. Try a different value by-pass capacitor in the screen circuit of the 6BG6G horizontal output tube. A value of .001 or .002 Mid usually will be found satisfactory.

I'm still plugging away at my HV issues, but figured I'd button up everything else.

That 2200 uF bi-polar capacitor does indeed work great in place of the old 1ohm @ 60Hz one. Since it was easy to unmount I decided to restuff it by uncrimping the can.

I used a small knife and flat bladed screwdriver to open up the crimp.
http://farm5.static.flickr.com/4111/4983823262_ab51eaa283_z.jpg

I used a heat gun to soften up all that old tar. Then I drilled a couple small holes and feed through the capacitor leads.
http://farm5.static.flickr.com/4144/4983823542_dcde7843ee_z.jpg

I used a small hammer and slowly, carefully worked my way around the base to fold the aluminum lip back over. I've heard that a hose clamp can help maintain the round shape while crimping too.
http://farm5.static.flickr.com/4133/4983225813_562a18b381_z.jpg

Here it is installed back in the set. Definitely tedious, but it does look nice I think.
http://farm5.static.flickr.com/4152/4983824606_ef1254b8f8_z.jpg

Very cool that a modern Ohmite resistor is nearly identical to the old one.
http://farm5.static.flickr.com/4124/4983224665_6a0807c57c_z.jpg

I watched your youtube on how you done that capacitor. nice job.

Thanks!

It's been suggested that I go over the glass/metal seams on the 19AP4 with something called VacuSeal. Can anyone fill me in on the benefits of this product and where to get it ?

It's a high vacuum leak sealant. You can find it at www.2spi.com

It's quite expensive.

John

Yes, that sounds like the stuff. I was told it would be expensive. I just wonder if it's worth it.

A little googling brought my to Phil's excellent CT-100 restoration (http://www.antiqueradio.org/RCACT-100Television.htm) in which he used it on a 15GP22.

Assuming that a 0.5 oz bottle is enough, I'll have to run the $36 + shipping costs by the set's owner.

I have a Thordarson cross-reference book that would tell you what alternate flys you can use. Since you already have the universal fly on the way, you sound like you are okay. Let me know and I'll dig it up for you. BTW, it does not just cover Thordarson, but all of the common parts suppliers of the time (RAM, Merit, etc.)

I have the universal replacement, but haven't tried it yet. It doesn't fit well on the chassis and the leads to the tube caps are a bit short.
It's also used and a little undersized compared to the existing one.
http://farm5.static.flickr.com/4125/4990123655_d77343f1bd_z.jpg

I have the Thordarson guide from 1978, but it doesn't list other brands. Please check your guide when you get a chance. Thanks!

A little googling brought my to Phil's excellent CT-100 restoration (http://www.antiqueradio.org/RCACT-100Television.htm) in which he used it on a 15GP22.

Assuming that a 0.5 oz bottle is enough, I'll have to run the $36 + shipping costs by the set's owner.
I applied Vacseal generously to the seams around two 15GP22s, which used up perhaps 1/6 of the 3-oz bottle. A little goes a long way! I have no idea what sort of seams a 19AP4 has, though.

Phil Nelson

I could only find Fly-40 as a replacement. I have another Merit only book, and it seems to skip right over the parts for this model entirely. Looking over the schematics for the Merit flys, I could not find one that was even close. Motorola part # is #24C792691

OK, thanks. The Sams mentions a Merit HVO-6 as a replacement, but I haven't been able to track one down.

There's a few HVO-7's out there, maybe they would be close enough?

http://cgi.ebay.com/12-Emerson-TV-part-HVO7-HV07-/300468172634?pt=Vintage_Electronics_R2&hash=item45f54c775a

Not affiliated

Hmmm. Hard to say without a datasheet, but I looked at the other HVO-7 he has listed and this is in the description:

"Merit HV0O-7 Horiz. Output Approx 14K.V. Output with AFC replaces HVO-6 for tues up to 24 inch. "

That sounds promising! Thanks for the link.

Yes, last I heard.
"I’ve actually talked to Sandy about Jim Obermeyer before and I’ll definitely be taking the cabinet there."

I'm really curious to see what a pro can do with it. I'm guessing the top needs to be re-veneered ? Just about everything in that darn antique shop it came from had some cabinet damage.

The logistics of having the set picked up have been comical at times. If I'd had the opportunity to go get the cabinet myself I certainly would have. Two tiny kids and a dad driving off to Chicago for the weekend would make for a stir crazy wife. I have to put my family first.

Luckily my Mom was willing to get the cabinet but forgot all about it her first trip back to Chicago. She's now closing on her house there and figured this was my last chance to get the cabinet apart from making the trek myself. On her way up the Jeep died on her and a friend she took with her. A day late and having to deal with movers and fixing things around the house made me tell her to "forget it".

Gold Coast (the antique store that's been nice enough to hold the cabinet for, well, months) isn't even open today. I had to pay someone to come in on their day off just to open the door and hand the cabinet off. Luckily this story has a happy ending as Mom pulled through by finding another relative that I've hardly met to go up and get the cabinet for me! It's currently on it's way back to her house were the movers will pack it and bring it to Tennessee. I'll get to see the cabinet by the weekend.

I owe a lot of big THANK YOU's to a lot of people. My family and especially Bob for picking up the set, putting other stuff aside he was excited about working on, and for restoring the set for me. Another big thanks for all of you that helped him with your posts. :thmbsp:

As soon as this comes together I'll absolutely post plenty of pictures.

I have another bit of good news. I scored a NOS Merit HVO-6 this morning on eBay. Hopefully, that will will do the trick and I can call this project done :)

I finally received the Merit HVO-6 and managed to hook it up. It's not the greatest fit, but good enough to try out.
http://farm5.static.flickr.com/4130/5040413415_4d11bbe72c_z.jpg

Nuts! The dark lines are less pronounced, but still there :(
http://farm5.static.flickr.com/4091/5041035548_342ca15896_z.jpg

However, I discovered that the capacitor hanging off the flyback has a big effect on those lines.
I was able to pretty much eliminate them by tweaking the value :D I think I'll button this set up and call it done!
http://farm5.static.flickr.com/4089/5041035440_e84e999d05_z.jpg

Hey! I have those dark lines too :( I'll have to try the cap trick, though I noticed I have a bad (or suspect!) vert lin coil, too...

I had the same veritcal lines in my Sylvania after replacing the yoke until I replaced the balancing capacitor in the yoke with the correct value.

John