Yeah! Another Admiral restoration project :drool:

This time it's the console on the left with a 21B1 chassis run #2.

http://farm7.staticflickr.com/6012/5966132630_3a4a94ff83_z.jpg (http://www.flickr.com/photos/70039806@N00/5966132630/)

It's a bit more primitive than the run #14 chassis I just restored. For example it lacks the couplates and gated AGC you'll find in the later runs. Also, it's not copper plated, but luckily, it's not rusty - just very dirty. It also has the original metal back.

http://farm7.staticflickr.com/6143/5965577739_52f6624af0_z.jpg (http://www.flickr.com/photos/70039806@N00/5965577739/)

Someone added crappy casters at some point. I'll be removing those.
http://farm7.staticflickr.com/6133/5966133940_764c3fce3d_z.jpg (http://www.flickr.com/photos/70039806@N00/5966133940/)

Here it is up on the workbench.
http://farm8.staticflickr.com/7161/6474837963_99b4363917_z.jpg (http://www.flickr.com/photos/70039806@N00/6474837963/) http://farm8.staticflickr.com/7029/6474839325_e6d9621075_z.jpg (http://www.flickr.com/photos/70039806@N00/6474839325/)

Original owner ?
http://farm8.staticflickr.com/7030/6474839991_4455c234ef_z.jpg (http://www.flickr.com/photos/70039806@N00/6474839991/)


I found evidence of many old repairs under the chassis.
http://farm8.staticflickr.com/7020/6474841349_7f9307a69e_b.jpg (http://www.flickr.com/photos/70039806@N00/6474841349/)

First, I popped out the 5U4 rectifier and power it up. All the tubes lit up and I get what I expected on the secondary.

The flyback and yoke resistances check out OK too.
http://farm8.staticflickr.com/7143/6474840667_2cc0e30056_z.jpg (http://www.flickr.com/photos/70039806@N00/6474840667/) http://farm8.staticflickr.com/7168/6508418135_739d87cce1_z.jpg (http://www.flickr.com/photos/70039806@N00/6508418135/)

Uh-oh! Bad vertical output autotransformer :tears:
I was hoping I could find a break near the output lead and repair it. Nope.
http://farm8.staticflickr.com/7175/6474837153_c06b51fbd4_z.jpg (http://www.flickr.com/photos/70039806@N00/6474837153/) http://farm8.staticflickr.com/7151/6474837497_699982eb2f_z.jpg (http://www.flickr.com/photos/70039806@N00/6474837497/)

Uh-oh! Bad vertical blocking oscillator transformer :tears:
http://farm8.staticflickr.com/7018/6474836763_8befe8f6ed_z.jpg (http://www.flickr.com/photos/70039806@N00/6474836763/)

Not to worry. Videokarma member kvflyer (AKA Don) to the rescue :banana:
The new transformers on the right just arrived in the mail and measure good.
http://farm8.staticflickr.com/7012/6508419299_73bfba1d6d_z.jpg (http://www.flickr.com/photos/70039806@N00/6508419299/)

I'm almost done recapping and replacing many out of spec resistors. So many in fact, there won't be many original parts left in this set!

There are also many ugly old repair attempts. The horizontal oscillator and output circuit is a good example. Several resistors have been replaced with ones of very different values. A couple capacitors have been tacked in that aren't even on the schematic. Worst of all, the HOT cathode has been shorted directly to ground bypassing the 47 ohm resistor and filter cap.
http://farm8.staticflickr.com/7010/6514575617_9a6f2727e0_z.jpg (http://www.flickr.com/photos/70039806@N00/6514575617/)

Here it is cleaned up.
http://farm8.staticflickr.com/7172/6514576089_fc09fb59de_z.jpg (http://www.flickr.com/photos/70039806@N00/6514576089/)

I've been testing all the mica caps with a Simpson 383A Capacohmeter. So far, they're all still good.
http://farm8.staticflickr.com/7002/6514575837_701813718f_z.jpg (http://www.flickr.com/photos/70039806@N00/6514575837/)

The big 3K candohm power resistor is burned out.
I wonder if this 15W aluminum housed resistor will do if mounted properly ?

http://farm8.staticflickr.com/7156/6514630713_70295b04ff_z.jpg (http://www.flickr.com/photos/70039806@N00/6514630713/)

Bob,

I am very fortunate that my 26R12 was not hacked up like yours. Actually, when I bought it working from a guy about 20 miles from here, he told me it worked. He had quite an assortment of what I would call "Desirable" sets. Anyway, it did work so it was just a matter of replace caps, test, replace caps, test etc. I was lucky that all coils and transformers were good.

Just FYI, it worked fine for about 2 hours and then I heard a "POP" and the vertical collapsed to about half. I was not able to make it bigger with the height control (clue #1) but the vertical linearity did work. Voltages did not change whilst rotating the height control (more confirming clue #2). I tried lots of stuff and was unsuccessful so I put it down.

One of the guys, I think Dennis, at ARF suggested "tin whiskers" on the height control. Removing, cleaning the outside and the problem was gone. Lesson learned by me, remove controls, clean the outside a well as the carbon track and reinstall.

I have an NOS RCA 16TP4 in mine. Not aluminized so it isn't super bright. And I think I found out why it was NOS in the box for so many years. There are about three spots on the face where the phosphorus is missing. Factory defect. But you really have to look for them so, "No Worries Mate!".

Sorry if I hijacked your thread. It is nice to follow this thread...

Not at all - comments are most welcome. This CRT is not aluminized either so I expect it will be quite dim compared to the Silverama CRT in the last set I restored.

Wow, that set sure had a lot of "issues." With all those hack repairs, maybe that's why they put casters on it :D

Fabulous work as usual, Bob.

-Clark

Great thread so far Bob :yes: - Lucky about getting some replacement vertical transformers, in all my TV adventures over the years I've only come across one that had an open circuit vertical blocking osc transformer. By the way I keep noticing that speaker on its front at the back of your bench, just curious as to why it just sits there? Is it one of those things that you keep meaning to move and forget about :D I have things like that on my workbenches..:yes:

Wow, that set sure had a lot of "issues." With all those hack repairs, maybe that's why they put casters on it :D

Fabulous work as usual, Bob.

-Clark

LOL - could be :) I confirmed that the sets current owner has tile floors so I'll be putting felt pads on the bottom. I just hope the holes drilled for those casters didn't crack the bakelite.

This set sure has been rather interesting to work on. I'd say the oddest "repair" so far was the addition of an extra 470 pF mica cap into the horizontal oscillator circuit where none belonged.
It the one turned around so no color dots are showing. I assumed that one of the originals must be bad, but, nope, they're all good.

http://farm8.staticflickr.com/7011/6521863213_0aa0cab9aa_z.jpg (http://www.flickr.com/photos/70039806@N00/6521863213/)



I got around to checking all the tubes last night and was surprised to find there all quite good except for one. The 6AC7 video output tube shows a short on the plate so I'll replace it.

...By the way I keep noticing that speaker on its front at the back of your bench, just curious as to why it just sits there? Is it one of those things that you keep meaning to move and forget about :D I have things like that on my workbenches..:yes:

Ah, that's a field coil speaker for an Admiral 20X1 chassis. I've been working on 3 of them in between these 21B1 Admiral chassis so I just left it up there for convenience. I really should put it somewhere safer though. I'd hate to tear the cone :sigh:

...
Ah, that's a field coil speaker for an Admiral 20X1 chassis. I've been working on 3 of them in between these 21B1 Admiral chassis so I just left it up there for convenience. I really should put it somewhere safer though. I'd hate to tear the cone :sigh:

When I have a speaker, now the first thing I do is to tape a piece of heavy corrugated cardboard cut to the exact size to the speaker over the front. Of course, it is easy to drop those needle nose pliers or screwdrivers just at the wrong time. They always seem to find the backside of the speaker. :D

kvflyer wrote: the first thing I do is to tape a piece of heavy corrugated cardboard cut to the exact size to the speaker
So do I, to avoid the great sorrow experienced more than once! :cry:

kvflyer wrote: the first thing I do is to tape a piece of heavy corrugated cardboard cut to the exact size to the speaker
So do I, to avoid the great sorrow experienced more than once! :cry:

Yes, we (unfortunately) learn from experience don't we? :tears:

OK, the speaker is safely stored away ;)

I restuffed the electrolytics, finished recapping and installed the replacement vertical transformers.
http://farm8.staticflickr.com/7148/6523966605_4eb47b4636_b.jpg (http://www.flickr.com/photos/70039806@N00/6523966605/)


http://farm8.staticflickr.com/7142/6523966907_8c3108ffff_b.jpg (http://www.flickr.com/photos/70039806@N00/6523966907/)

The tubes have been installed and it's ready for a 1st test. The tubes wit green tape test OK, but just into the good range.
http://farm8.staticflickr.com/7158/6523991235_75e13f53cc_b.jpg (http://www.flickr.com/photos/70039806@N00/6523991235/)

What kind of a tool do you use to peel open the bottom lip of those electrolytic can caps? I've tried a couple different things and always end up botching things up. That and I usually slip and I poke myself with whatever tool and get real angry. :D

Yea, what kevin said. I'm just as sick a' skewering myself as him....Also you do a neater job than me and I'd like to do as neat of a job as possible especially considering that I'm going to be getting a CTC-4 soon...

I too have a few scars on my left hand from various tools slipping. Here's what I'm currently using. I start off with the pocket knife.
If that can pry up a little section, I move on to the small screwdriver. If not, I use the pliers. Note they do not have serrations so they don't chew up the aluminum all that much.
http://farm8.staticflickr.com/7147/6524615555_f57c91779f_z.jpg (http://www.flickr.com/photos/70039806@N00/6524615555/)lickr

I powered the set up slowly and all seemed OK so I went for full power. I was really surprised to see a distorted image. A little control tweaking and I got a stable image :banana: Those relacement vertical transformers are working just fine :yes:

Barely any sound though :scratch2:
http://farm8.staticflickr.com/7027/6524391473_bf9bb6946e_z.jpg (http://www.flickr.com/photos/70039806@N00/6524391473/)

After a little investigation, I discovered a broken antenna lead. Fixing that helped a little.
http://farm8.staticflickr.com/7161/6524616055_f0aa790c91_z.jpg (http://www.flickr.com/photos/70039806@N00/6524616055/)


Then, I tried rocking each tube in it's socket and, bingo!, a 6AL5 wasn't making good contact. Plenty of sound now :music:
http://farm8.staticflickr.com/7015/6524615811_d51ddd1da6_z.jpg (http://www.flickr.com/photos/70039806@N00/6524615811/)

Next, I hooked up a better signal source. The picture is pretty good, but rather dim. Not surprising really for an original CRT.
http://farm8.staticflickr.com/7173/6524616361_99d397a0f1_z.jpg (http://www.flickr.com/photos/70039806@N00/6524616361/)

I switched to a dead channel and I have vertical bars similar to the last set I restored with the same chassis. This time there's one pronounced stripe and several faint bars.
I'll do some troubleshooting over the weekend. All in all, a very successful first power up :)
http://farm8.staticflickr.com/7172/6524616767_81b2edfdbf_z.jpg (http://www.flickr.com/photos/70039806@N00/6524616767/)

43-08 54th st
I wonder if this is where it originally resided?

http://maps.google.com/maps?q=43-08+East+54th+Street+new+york&hl=en&ll=40.743412,-73.910812&spn=0.006381,0.013937&sll=41.796409,-87.627046&sspn=0.006279,0.013937&vpsrc=0&hnear=43-08+54th+St,+Woodside,+Queens,+New+York+11377&t=h&z=17&iwloc=A&layer=c&cbll=40.743415,-73.910814&panoid=FaS9EpHKi6ZF221u1oUwxg&cbp=12,270.12,,0,0.05

43-08 54th st
I wonder if this is where it originally resided?

http://maps.google.com/maps?q=43-08+East+54th+Street+new+york&hl=en&ll=40.743412,-73.910812&spn=0.006381,0.013937&sll=41.796409,-87.627046&sspn=0.006279,0.013937&vpsrc=0&hnear=43-08+54th+St,+Woodside,+Queens,+New+York+11377&t=h&z=17&iwloc=A&layer=c&cbll=40.743415,-73.910814&panoid=FaS9EpHKi6ZF221u1oUwxg&cbp=12,270.12,,0,0.05

Could be Kenosha, Wi.:scratch2:

Could be Kenosha, Wi.:scratch2:

Kenosha?

N.Y. was the only one I found with a 43-08 in the address but then this is sixty years later.

I switched to a dead channel and I have vertical bars similar to the last set I restored with the same chassis. This time there's one pronounced stripe and several faint bars.
I'll do some troubleshooting over the weekend. All in all, a very successful first power up :)
http://farm8.staticflickr.com/7172/6524616767_81b2edfdbf_z.jpg (http://www.flickr.com/photos/70039806@N00/6524616767/)

In case you haven't seen this yet over on ARF... mbear2k posted a link to a scan of his Admiral notes from Rider. Take a look at page 4. Still no value for the RF choke, but maybe it's the same as L405 used eleswhere in the circuit? It does identify the three componets being available as a combined filter(part #A34596).

http://www.oldtubes.net/library/free_manuals/Admiral_TV_Trouble_Cures-hirez.pdf

I guess he posted it here too. Great stuff.

http://www.oldtubes.net/library/free_manuals/Admiral_TV_Trouble_Cures.pdf

Thanks for the link. Adjusting the drive got rid of the line but I still have the faint bars.

In case you haven't seen this yet over on ARF... mbear2k posted a link to a scan of his Admiral notes from Rider. Take a look at page 4. Still no value for the RF choke, but maybe it's the same as L405 used eleswhere in the circuit? It does identify the three componets being available as a combined filter(part #A34596).


Hmm. I don't see L405 in the parts list for the 21B1 chassis.

It says the RF choke is part # 73B8-3. I checked in my Thordarson cross reference, but it's not listed.

Does anyone have a cross reference guide for other suppliers like Merit or Stancor they can check ?

Using the notes mbear2k posted, I was able to completely eliminate the retrace lines :)
http://farm8.staticflickr.com/7161/6530362365_bd5390347c.jpg (http://www.flickr.com/photos/70039806@N00/6530362365/) http://farm8.staticflickr.com/7011/6530362645_c484e3580d.jpg (http://www.flickr.com/photos/70039806@N00/6530362645/)

I also put a scope on the horizontal output tube's grid and saw this.
There's some ringing in the waveform that most likely accounts for the vertical bars on the left.
http://farm8.staticflickr.com/7015/6530363003_2d948c0bea.jpg (http://www.flickr.com/photos/70039806@N00/6530363003/)

The signal at the preceding stage (horizontal oscillator) looks correct so I'm not sure where it's coming from.
http://farm8.staticflickr.com/7028/6530363265_a902c24f2f.jpg (http://www.flickr.com/photos/70039806@N00/6530363265/)

Otherwise, the set is playing fine, just a little dim and washed out. I may try rejuvinating the picture tube :scratch2:
http://farm8.staticflickr.com/7171/6530363743_cde55feb3a.jpg (http://www.flickr.com/photos/70039806@N00/6530363743/)

A little web searching pulled up this thread describing exactly the same problem and some solutions: http://www.antiqueradios.com/forums/viewtopic.php?f=3&t=108670

I put my scope probe near the yoke and found really pronounced ringing.
http://farm8.staticflickr.com/7175/6533421975_7972fd7810.jpg (http://www.flickr.com/photos/70039806@N00/6533421975/)

I flipped though some 21B1 schematics and found the last revisions which did include that filter as part of normal production. No values given though so I'll have to experiment.

A little web searching pulled up this thread describing exactly the same problem and some solutions: http://www.antiqueradios.com/forums/viewtopic.php?f=3&t=108670


Thanks for posting the ARF link. I hadn't read that one before, that was some very informative reading. Now if I could only remember all this stuff I read for more than a couple days, I could be like smarter :screwy:

Yeah, lots of good info in that thread. I took a closer look at my scope snapshot and estimate the ringing frequency at roughly 180kHz just like Tom noted. I see what chokes I have on hand and try to cobble together something with that resonant frequency.

I used the capture mode on my scope to analyze that ringing more closely and it's definitely around 180 kHz.

http://farm8.staticflickr.com/7168/6551331855_5d9cf709f0.jpg (http://www.flickr.com/photos/70039806@N00/6551331855/)

Here's a schematic of a later production run showing the damper filter and unknown inductor L406.
That mystery value might be revealed in Riders Vol #13, but those pages are missing from my copy :tears:
http://farm8.staticflickr.com/7155/6551331945_2621531ded.jpg (http://www.flickr.com/photos/70039806@N00/6551331945/)

Knowing that it's a 0.0068uF cap and 180kHz I pulled them into a resonance formula and got about 115uH. I rounded up to the next standard value - 120uH and ordered a few.

I hope it does the trick.
http://farm8.staticflickr.com/7157/6551331913_0fc7337fe9.jpg (http://www.whatcircuits.com/lc-resonance-frequency-calculator/)

Something else I'm working on is the washed out picture. At first I thought it might just be a worn out CRT, then I got a scope on the 6AC7 video output tube.
It turns out the signal on the grid is about 33% low and so is the output going to the pix tube. Now, I'm going through the IF stages hoping to boost the gain.

As with every Admiral I've worked on lately, most of the resistors are way off value. This 1K resistor is measuring almost double that.

http://farm8.staticflickr.com/7148/6552006213_9f7bbea553.jpg (http://www.flickr.com/photos/70039806@N00/6552006213/)

You too huh? I seem to be having a run of high resistors lately...Maybe they're conspiring against us? :naughty:

Something else I'm working on is the washed out picture. At first I thought it might just be a worn out CRT, then I got a scope on the 6AC7 video output tube.
It turns out the signal on the grid is about 33% low and so is the output going to the pix tube. Now, I'm going through the IF stages hoping to boost the gain.

As with every Admiral I've worked on lately, most of the resistors are way off value. This 1K resistor is measuring almost double that.

http://farm8.staticflickr.com/7148/6552006213_9f7bbea553.jpg (http://www.flickr.com/photos/70039806@N00/6552006213/)

You too huh? I seem to be having a run of high resistors lately...Maybe they're conspiring against us? :naughty:

And so the resistance movement has begun!!!!!!:smshot::jawdrop::pistols::uzi:

LOL.

I'll get those resistors in line! :whip:

As for the IF alignment, I tried two different sweep generators and what I'm seeing just doesn't make sense. The gain is lousy and the response curve is nothing like it should be. I'm starting to think I might have a bad coil or cap in there somewhere. I still have the set I just restored with the same chassis so next I'll compare them side-by-side.

I also cleaned out the HV cage. Pretty nasty in there.
http://farm8.staticflickr.com/7175/6557420171_5a575eaa88.jpg (http://www.flickr.com/photos/70039806@N00/6557420171/) http://farm8.staticflickr.com/7150/6557420493_732b37e069.jpg (http://www.flickr.com/photos/70039806@N00/6557420493/)


Terrible idea to put the AC power plug so close to the fylback :no:
Amazingly, the fuse is actually the correct 1/4 Amp. I usually find one more like 10 Amps :rolleyes:
http://farm8.staticflickr.com/7007/6557420789_58c28a908a.jpg (http://www.flickr.com/photos/70039806@N00/6557420789/)

...

Terrible idea to put the AC power plug so close to the fylback :no:
Amazingly, the fuse is actually the correct 1/4 Amp. I usually find one more like 10 Amps :rolleyes:
http://farm8.staticflickr.com/7007/6557420789_58c28a908a.jpg (http://www.flickr.com/photos/70039806@N00/6557420789/)

The porthole Zenith that I have (still in queue) had exactly that! A 10 amp fuse in the Horizontal circuit. Needless to say, the flyback looked like a burned pork chop. I was lucky to find an NOS Merit thanks to one of the guys on ARF.

I remember reading one of the production changes in the chassis series was including that fuse to satisfy U/L requirements.

Wow!

I would imagine, from the factory, that the wires were dressed a little better than that! At least I hope so. Does the other duplicate chassis look the same in that area?

Anyway, I zoomed in via flicker. The outer flyback coating looks like it is completely "punched through!" Are you sure the outer windings are 100% OK. Did you test it with your EICO flyback and yoke tester? I think that you said that you had... It wouldn't have taken much more abuse before that flyback ended up as toast!

I slid some heatshrink tubing over the AC wires and pushed them out of the way. It seems to be OK. I've had the set playing a few hours with no HV problems. I should melt some new wax over it just to be safe.

Here's a production run #5 chassis (this set is run #2). Copper plating, but same bad design.
http://farm8.staticflickr.com/7029/6561006687_07826d6e31.jpg (http://www.flickr.com/photos/70039806@N00/6561006687/)

Finally, by production run #14 they had the sense to relocate the AC plug.
http://farm8.staticflickr.com/7166/6561024597_9485d48f42.jpg (http://www.flickr.com/photos/70039806@N00/6561024597/)

I hope you have decided against rejuvinating the CRT for now. You could easily kill it. I've got a CRT rejuvinator/tester, and have never used the rejuv feature with it. I've never seen a rejuvinated tube that lasted more than a few months at the most.

Your set is looking fantastic! I'm really enjoying the progress you are making!

Bruce

Thanks. No, I'm not going to rejuv. this picture tube. It's very watchable if you dim the lights a little.

My Sencore CR70 has an auto-restore and several rejuvinate functions. I've only used them on CRTs that were really weak. It helped a little - couldn't say for how long though as I don't play my sets that much.

I received my filter parts over the weekend and finally had a chance to try it out tonight. Here's where I wired it in.
I'll do a neater job once I'm done tweaking it. I figure I can use one of the unused damper socket lugs for a tie point.
http://farm8.staticflickr.com/7152/6573231119_f0de32602d.jpg (http://www.flickr.com/photos/70039806@N00/6573231119/)

It definitely reduces, but doesn't eliminate the ringing. I'll try tweaking the capacitor value to reduce it even more.
http://farm8.staticflickr.com/7166/6573231511_83ce0a5cdb.jpg (http://www.flickr.com/photos/70039806@N00/6573231511/)

Unfortunately, the bars are still there but not as bad as before I think.
http://farm8.staticflickr.com/7173/6573231901_ee28eb2c68.jpg (http://www.flickr.com/photos/70039806@N00/6573231901/)

I also tried several different 6W4 and 6AX4 damper tubes with little change.

I re-read those Admiral servicing notes more carefully and discovered that the filter must installed inside the HV cage not under the chassis. I'm not sure if that affects the circuit or it's a safety issue, but I went ahead and moved it. I mounted a terminal strip to an existing hole and soldered in the components.
http://farm8.staticflickr.com/7023/6639944943_0c916d8725_z.jpg (http://www.flickr.com/photos/70039806@N00/6639944943/)

I also tweaked the capacitor value. I figure the ripple is a harmonic of 15,750 Hz. The closest to what I saw on the scope are 173 and 189 kHz. A little experimenting found that 189 kHz was correct so I went with about 5900 pF in parallel with the 120 uH inductor.

Unfortunately, while mucking around in the HV cage I managed to snap off a flyback lead. I melt back the wax a little and managed to solder it back on then coated it with corona dope. Seems to work fine after 10+ hours of playing.
http://farm8.staticflickr.com/7034/6639945257_8bfb2d078a_z.jpg (http://www.flickr.com/photos/70039806@N00/6639945257/)

Then on to cleaning out the tuner and going through the alignment procedure.
I found this date stamped inside the tuner.
http://farm8.staticflickr.com/7013/6639944631_ce9d7d9fbe_z.jpg (http://www.flickr.com/photos/70039806@N00/6639944631/)

Here's the IF response.
http://farm8.staticflickr.com/7166/6639945667_15d4dab639_z.jpg (http://www.flickr.com/photos/70039806@N00/6639945667/)

I spent a lot of time fighting with the focus coil, centering lever, ion trap magnet and yoke. It's not perfect, but certainly better than what I started with.
http://farm8.staticflickr.com/7035/6639946173_c09a7040e8_z.jpg (http://www.flickr.com/photos/70039806@N00/6639946173/)

Here are a couple screenshots. You can see how the bottom right-corner bends up a little.
Another issue is an occasional hiss / crackle in the audio. it sounds just like a HV leak, but I can pull the HO tube and the hiss remains :scratch2:

http://farm8.staticflickr.com/7009/6639946739_3f5c46b4dc_z.jpg (http://www.flickr.com/photos/70039806@N00/6639946739/) http://farm8.staticflickr.com/7174/6639947839_721f450cff_z.jpg (http://www.flickr.com/photos/70039806@N00/6639947839/)

Those pictures looking pretty stunning Bob :yes: Are those bars still there even after moving the modification to the high voltage cage area?

Those pictures looking pretty stunning Bob :yes: Are those bars still there even after moving the modification to the high voltage cage area?

Thanks. I guess if you have to ask then they're gone ;)
Seriously though, they are still there but much fainter than before. Relocating the filter didn't have much effect but switching from 6800 to 5900 pF did. I put a couple caps in parallel (5600 + 300) to get that oddball value.

It is about time you got back on this TV! What's going on, did you have a holiday or something???

Seriously, looks good and I am glad that you have it going so well. Please keep us posted Bob...

Lol - I actually have been working on it every day. Easily the most frustrating chassis I've worked on to date.
Now, I need to go back to the last one I restored and try installing the filter. And I have two more sets with the same chassis to restore some day :drool:

I'm still chasing down the hiss and squeal in the audio. I pulled all the tubes so I'm down to just a functioning tuner and sound output. The squeal remains.
My next thought was bad mica caps, but they all appear to be ceramic. Even so, I'm going to test each one.

All the caps tested OK, but I think I found the problem. It turns out it works better if you actually solder all the connections :stupid:
http://farm8.staticflickr.com/7147/6646096277_6ca3388a89_z.jpg (http://www.flickr.com/photos/70039806@N00/6646096277/)
Now on to the cabinet.

Naah. Just makes for interesting problems later.

Please dont ask how I know this... Vivid memories of an RCA roundie flyback and one missed solder connection and a jumpy width that didnt happen until the entire set was put back together completely... set back and all.

I let the set play for a couple hours and the audio issue has resurfaced. My next thought is that it could be the cap across the audio output transformer breaking down. The original was 600 v and I replaced it with a 630 v. I recall seeing a service note about replacing this cap with a higher voltage one.

That's weird if it's breaking down in that location. How many volts across it?

I always wondered why that particular cap was rated 1000vdc in sets, seems to me it shouldn't have more than about 400v across it at any point in time.

I suppose the audio signal can add to the DC volts, but I'd of never thought the audio signal would be very much for a couple watts TV speaker. :scratch2:

I always wondered why that particular cap was rated 1000vdc in sets, seems to me it shouldn't have more than about 400v across it at any point in time.
Positive-going back-EMF spikes can get stacked 'on top' of the supply voltage, 'specially if the voice coil were open.

Positive-going back-EMF spikes can get stacked 'on top' of the supply voltage, 'specially if the voice coil were open.

This question often comes up. Yes, there are spikes on that capacitor and it should be at least 1000VDC. I know that there are Orange Drops rated at 1600VDC out there. Might be a good thing to have. Also, not having a speaker connected can cause a high reflection of the signal back to the tube. I know this is just a 6V6GT single ended amplifier. But I have seen a few audio amplifiers that had the tube sockets burned. All because of the reflected signal. I don't think that you have to not use it now, but I would get some 1.6KV caps the next time you order some.

How bout a couple double value caps in series?

I imagine that would work too. I do have a few of those orange drop 1600v on hand though. I'll install one later tonight and clean out the tube socket pins too.

I started on the cabinet this afternoon. 55 F and sunny :D Never expected to be working on an unheated porch in January!

No chips or deep scratches. I'm going to clean it with some mild detergent then buff with Novus #2

The CRT gasket foam is rock hard and crumbling. I'll replace it with some closed cell foam insulation.
http://farm8.staticflickr.com/7028/6649762935_ab22fdb370_z.jpg (http://www.flickr.com/photos/70039806@N00/6649762935/)

http://farm8.staticflickr.com/7014/6649763375_314bd51fe9_z.jpg (http://www.flickr.com/photos/70039806@N00/6649763375/) http://farm8.staticflickr.com/7161/6649763857_741932e038_z.jpg (http://www.flickr.com/photos/70039806@N00/6649763857/)

I removed the faceplate and cleaned the cabinet with some warm soapy water.
http://farm8.staticflickr.com/7173/6650977645_ab912f0f87_z.jpg (http://www.flickr.com/photos/70039806@N00/6650977645/)

The speaker cloth has faded quite a bit.
http://farm8.staticflickr.com/7156/6650977259_9bb01b4738_z.jpg (http://www.flickr.com/photos/70039806@N00/6650977259/)

I recall someone had asked about the clarity of the faceplate. Here it is before any cleaning. I hope it clears up.
http://farm8.staticflickr.com/7157/6650978051_b4e0cd7060_z.jpg (http://www.flickr.com/photos/70039806@N00/6650978051/)

There's some flashing left from the bakelite molding process.
http://farm8.staticflickr.com/7142/6650979025_ce86e3ac25_z.jpg (http://www.flickr.com/photos/70039806@N00/6650979025/)

Time to finally lose the caster wheels. Now I can bring it inside.
http://farm8.staticflickr.com/7157/6650978439_5d64f2593f_z.jpg (http://www.flickr.com/photos/70039806@N00/6650978439/) http://farm8.staticflickr.com/7032/6650979699_a416aac01f_z.jpg (http://www.flickr.com/photos/70039806@N00/6650979699/) http://farm8.staticflickr.com/7018/6650980383_3190b79a33_z.jpg (http://www.flickr.com/photos/70039806@N00/6650980383/) http://farm8.staticflickr.com/7017/6650993985_86bea7ffd4_z.jpg (http://www.flickr.com/photos/70039806@N00/6650993985/)

I removed the faceplate and cleaned the cabinet with some warm soapy water....

The speaker cloth has faded quite a bit.
http://farm8.staticflickr.com/7156/6650977259_9bb01b4738_z.jpg (http://www.flickr.com/photos/70039806@N00/6650977259/)

Bob,

I see that you were able to remove the nuts that hold the speaker board to the cabinet. What method did you use? I started to take my speaker board out and the nuts didn't want to budge without breaking. Did you pry up on the two "capture" parts in the center of the nut? Did any of yours break?

I recall someone had asked about the clarity of the faceplate. Here it is before any cleaning. I hope it clears up.
http://farm8.staticflickr.com/7157/6650978051_b4e0cd7060_z.jpg (http://www.flickr.com/photos/70039806@N00/6650978051/)...

Bob,

I think it was me that asked about the clarity. I was able to polish the clear faceplate with no problem. But when I look at either one that I have (I have two) in bright light, the clear plastic has sort of a very faint swirl pattern in both of them. I suspect the plastic was about as clear as they could get it but there was still some kind of white swirl in it. Mind you, very faint and it doesn't affect the picture. But I was just interested to see if anyone else noticed it.

And for what it's worth, that foam gasket on mine was as crisp as a 50-year old wedding cake! I didn't replace it yet.

BTW, nice to see this restoration. My chassis is copper plated and the reason I have spare parts is because I bought a 16R12 for parts. Mine was missing the HV cage. I was lucky that both were copper plated.


Nice job as usual!

Looks like some idiot production manager was screaming at the workers to get productivity up. Which usually means the workers have to skip steps to keep the quality decent... So they didn't take the time to remove the flash.
http://farm8.staticflickr.com/7142/6650979025_ce86e3ac25_z.jpg

Bob,

I see that you were able to remove the nuts that hold the speaker board to the cabinet. What method did you use? I started to take my speaker board out and the nuts didn't want to budge without breaking. Did you pry up on the two "capture" parts in the center of the nut? Did any of yours break?
Bob,

I think it was me that asked about the clarity. I was able to polish the clear faceplate with no problem. But when I look at either one that I have (I have two) in bright light, the clear plastic has sort of a very faint swirl pattern in both of them. I suspect the plastic was about as clear as they could get it but there was still some kind of white swirl in it. Mind you, very faint and it doesn't affect the picture. But I was just interested to see if anyone else noticed it.

And for what it's worth, that foam gasket on mine was as crisp as a 50-year old wedding cake! I didn't replace it yet.

I used pliers on the four in the corners. I got a good grip on them and sort of unscrewed them while pulled back.
I tried to pry up the capture teeth with a small screwdriver on the rest, but couldn't manage it. I had to mangle them by bending them with needle nose pliers.
None broke though and I might be able to unbend and reuse them.

I propped it up in front of a window and, yes, it sure does have those swirls.
http://farm8.staticflickr.com/7169/6655504723_2d4e54e629_z.jpg (http://www.flickr.com/photos/70039806@N00/6655504723/)

Here it is after cleaning with warm soapy water and Novus #2. Not much of an improvement. Those swirls are definitely in the plastic and not surface dirt.
http://farm8.staticflickr.com/7175/6655505275_20bfc353f7_z.jpg (http://www.flickr.com/photos/70039806@N00/6655505275/)

Looks like some idiot production manager was screaming at the workers to get productivity up. Which usually means the workers have to skip steps to keep the quality decent... So they didn't take the time to remove the flash.


LOL - I bet you're right.

I'm just about done with the cabinet. Cleaning and buffing the speaker grille is a pain :drool:
There is some minor chipping along the top edge and discoloration from the control panel, but otherwise it came out great.
http://farm8.staticflickr.com/7028/6691263461_864f6a41f2_z.jpg (http://www.flickr.com/photos/70039806@N00/6691263461/)

That cabinet looks great. Was that just a hand buff with Novus #2?

That cabinet looks great. Was that just a hand buff with Novus #2?

Thanks! Yep. Around 6 passes on the top and 3 on the rest.

Now on to the control panel. Some areas appear to have been sprayed with some substance that effected the plastic.
It's a little foggy and bumpy - especially on the left side. Perhaps something like pledge reacted with it ?

I'm just going to buff it as best I can.
http://farm8.staticflickr.com/7146/6693021715_2802ec8c60_z.jpg (http://www.flickr.com/photos/70039806@N00/6693021715/)

http://farm8.staticflickr.com/7171/6693022457_8f48640bb9_z.jpg (http://www.flickr.com/photos/70039806@N00/6693022457/)

I finished buffing out the knobs and put the set back together.
I've had it playing for a few hours and it's working quite well :banana:

http://farm8.staticflickr.com/7011/6693835993_a8eb03aae0_z.jpg (http://www.flickr.com/photos/70039806@N00/6693835993/) http://farm8.staticflickr.com/7013/6693835719_430c7762a3_z.jpg (http://www.flickr.com/photos/70039806@N00/6693835719/)

Hi Bob, looks good. Thanks for taking the time to investigate those cloudy swirls in the faceplate. I think that in 1950, plastic technology was not quite perfected as it kinda is today. You really can't see the swirls in the clear plastic but they are there. No biggie.

Thanks for showing how you removed the speed nuts from the speaker board. I tried also to pry the capture teeth and was unsuccessful. I thought about just cutting them. But pooh-poohed that idea because I didn't want to be sorry later for being in such a hurry. I will go back and revisit that after I move to Florida. My 26R12 is already sitting in the den of my house down there.

When I get the speaker board out, I can investigate the flash from the Bakelite. I have one large scratch on the top of mine. Looks like someone sat a chassis on the top and slid it along. It is about 2.6" long.

My control cover door cleaned up nicely. And, the picture that I posted along time ago shows that my volume control knob was more of a mahogany color than a brown. One of the members of ARF sent me the correct color knob.

The 26R12 that I had as a teenager is long gone. But what I did was to modify the amplifier in the set with a Loudness Compentrol and change the 8" speaker to a Philips/Norelco dual cone 8" speaker. It did widen the frequency response. I doubt I will do it to my present set because as with your restorations, I strive for originality as it came from the factory.

Thanks for taking the time to document your restoration. Interesting how both of the chassis I had/have were copper plated. And, some of the 12" models came in both copper plated and cadmium plated. And, it is interesting that both of your vertical transformers went open. Do you think wet environment and corrosion or massive failure in the vertical circuit?

way2wise has the 14" version of this set as well. I don't know if he did a documentary on its restoration.

Looks real nice, Bob, and what a picture. Thanks for the tour.

The top picture on entry #64 shows a set top antenna in the background. Unit with the three push buttons. I always liked them. Who made it, Speco? I don't think it was Radion, which was a Chicago firm.

The top picture on entry #64 shows a set top antenna in the background. Unit with the three push buttons. I always liked them. Who made it, Speco? I don't think it was Radion, which was a Chicago firm.

It took me a while to find one of these. I can't find any name on it, bu it's an "American 5-K" according to this website (http://www.collectorkevin.com/antennas.htm#Link194134C0).

http://farm4.staticflickr.com/3463/5847501036_0aa336c5a1_z.jpg (http://www.flickr.com/photos/70039806@N00/5847501036/)

...Thanks for taking the time to document your restoration. Interesting how both of the chassis I had/have were copper plated. And, some of the 12" models came in both copper plated and cadmium plated. And, it is interesting that both of your vertical transformers went open. Do you think wet environment and corrosion or massive failure in the vertical circuit?

way2wise has the 14" version of this set as well. I don't know if he did a documentary on its restoration.

Thanks. Weird how they copper plated some chassis and not others. Only the yoke support is copper plated in this set.

I believe it was a massive failure that killed the vertical transformers. Most likely from one of the nasty hack repair attempts I found throughout the set.