Stock Photo:

http://www.tvhistory.tv/1959-Airline-WG5062A.JPG


Hello Folks,

As I hinted in my introductory post I have my first vacuum tube TV project. I recently rescued this set from an abandoned house scheduled for demolition. When I first discovered the set my intentions were to cannibalize it for parts because I already have experience repairing tube radios. Since I didn't care about the TV I broke the cardinal rule of untested vintage tube gear, I plugged it in! Well, it worked! Sort of. All the tubes lit up and the picture tube came on and I let power course through it's metallic veins for a few minutes. I don't know what happened, but a very vibrant and blue arc appeared between the Horizontal and Vertical control pots. I guess either a resistor shorted, or a cap burnt up. I felt of all the cap cans and none were even remotely warm. I decided to power down the set. Aside from this problem that manifested, I decided it was best to repair the set instead of chopping it up for parts. I didn't expect the set to even power on or I would have been a little less hap hazard. It's got some obvious signs that either a repair man or a gremlin has been inside. One of the cap cans has been removed and a large paper cap put in it's place. Also there are heavy plastic straws pushed over the adjustment pot shafts for the vertical and horizontal size control (bad terminology I'm sure). There is also some strange dual color wire that's been used to bridge the grounds on a set of heatsinks. I don't understand the wire's purpose as it appears to formerly been a fuse-able link, but the wire is at least 70s vintage and not original to the set. Also, someone at some point decided to cut the cord off (but still leave 7 inches on the cord)even though it was clearly removable from the rear of the set. They also cut the wires running to the lone speaker. When I opened the cab I found two dangling wires coming from a miniscule PT or choke (I can't tell at this point) so I assume they ran to the speaker through the bottom of the cab.

I plan on posting some pictures of the set as is, and then in the progressive states of repair.

As I understand it, this set is a "lesser" brand and not of a particularly desirable vintage. However, it is tube based, and because of that it has a spot in my heart. I know it's quite ignorant to have the intentions of parting something out, then potentially destroying it, then decided to fix it, but that's how I roll sometimes. Also given the fact that most of the tubes were tv specific, killing the set wasn't worth some unidentifiable transformers and a few tube sockets. I decided since I don't own any tube TVs, or any B&W TVs for that matter I should probably fix this puppy.

At this point I would like to know what yall's opinion of the set is as a restoration/fixable project. Did I do unrepairable damage to the set by letting this arc develop, as the picture tube was still "playing" when the arc developed and I powered the TV down? And where is a good place to find schematics? I understand everyone is loyal to rm here, but honestly I don't have the money for registration. It may sound stupid that someone is attempting refurbishing a piece of tube gear without any money, but I have a friend who works at a guitar store that services tube amplifiers and I can get components on the cheap cheap from him, usually. I was contemplating purchasing one off of epay but I don't have a credit card either. I would have to borrow a friends card and then pay half of what it would cost to join rm for a year, so I am torn. Also, I can't tell if the epay item is a complete manual like the screen shots at arf appears to show.

Link to epay item:
http://www.ebay.com/itm/Airline-WG-5060A-B-TV-Photofact-Repair-Manual-/120475140939?_trksid=m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA% 252BUA%252BFICS%252BUFI%26otn%3D31%26pmod%3D110512 325904%26ps%3D50

link to rm:
http://www.radiomuseum.org/r/montgomery_wg_5061a.html

I have a scan of the Sams manual. If you go to http://antiqueradio.org/contact.htm and send me your email address, I'll send it to you.

That TV's actually kind of cool looking, a little like my Philco Miss America.

I'm not familiar with this set, but I see 560V boost voltage on the height control and 255V on the horizontal hold, so if there were something funky around one of them, hijinks might ensue. After you get the schematic, you can check out components in the neighborhood where you saw arcing and also determine whether some previous "repairman" did dodgy things.

Looks like sort of a bare-bones design: only 12 tubes, including the CRT. That's good news in a way, since there are fewer parts to go bad and need replacement.

This is a series-string chassis, so use caution just as with an AC/DC radio. Come to think of it, the plastic straws on those adjustment pots might be factory-installed, to insulate you from Bzzzt.

"Bumblebee" or similar plastic-coated paper capacitors are always questionable, as are electrolytics.

I wouldn't be ashamed to give it a whirl, anyhow. B/W TV design had been pretty well figured out by 1959, so even a bare-bones set might perform better than you think. Who knows, maybe you can just throw in a few new caps and have it back on the road.

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

great save!! hope you can get her running!

I pulled the chassis out of the cabinet and give it a once over with the air compressor. Man at the 50 years old dust I ate, I guess I should invest in some paper dust masks next time.

Well I did a quick inspection of the unit, I've got a few resistors cracking and showing oxidized leads. Also I saw some oxidation underneath both of the cap cans. I didn't notice anything funky looking where I saw the arc at, but I assume it was created by something down-line and not at the site of arcing. I inspected some of the tubes in anticipation of using a friend's hickok when I noticed one of the tubes are different than specified by the tube layout printed on the back of the tv and on the chassis. The tube is supposed to be a 12DQ6A, but instead is equipped by a 12CU6. I looked these up on rm and noticed a distinct voltage difference off pin 5.

http://www.radiomuseum.org/images/tubeenvdiag_klein/12cu6.gif
This is the equipped tube showing 72.5 volts on pin 5

http://www.radiomuseum.org/images/tubeenvdiag_klein/12dq6a.gif
This is the required tube showing 22.5 volts on pin 5

I believe I am reading this right, they are not listed as compatible tubes so I assume this is the wrong tube.

I plan on ordering caps next week, and testing the specs on the resistors, specifically the suspect ones.

According to this website, these are valid substitute for a 12DQ6A - "12GW6, 12DQ6B, 12DQ6, 12CU6, 12GW6" http://www.nostalgiaair.org/tubes/12dq6a.htm

According to this website, these are valid substitute for a 12DQ6A - "12GW6, 12DQ6B, 12DQ6, 12CU6, 12GW6" http://www.nostalgiaair.org/tubes/12dq6a.htm

Well, thanks for that. I guess the way that the picture was small and pixelated made me think they were different values. I looked at two different tube comparison and compatibility websites and they weren't ever listed as compatible. I need to get stronger on my tube nomenclature. Thanks for the help.

I must apologize for not providing pictures of my journey to restore this tv. I have a 10 year old sony digital camera but the batteries are shot and I didn't feel like have to sacrifice a plug-in to take pictures. One day this week I may get some pictures up here because I know I like to follow along and view the handiwork of someone else when they have a continuing build or restoration.

I started cutting the old electrolytic(s) out, I usually start with replacing these and move on the the paper caps. Mica and cermaic will be checked on an individual basis. What I noticed was that while one whole can cap had been replace by a tech sometime in the later 60s, an addition to the circuit had been added because one of the 3 caps inside can 2 had went bad. I also noticed the original Wells Gardner picture tube had been replaced with an RCA Silverama. There had been some crazy mess of wires added to complete a circuit, or act as a ground. I have removed it and will identify it's implied function later.

I have a friend with a high end hickok at his guitar store so he invited me over for dinner (while he's at work) and a night of playing with the tube tester. I can't wait.

I have two questions for y'all, where do y'all order caps from? I traditionally ordered from mouser but they aren't carrying the values I need for this project. Digikey has what I need but they are no stock items and I have to order a minimum of 25.

Also, since one original can has already been lost, should I save myself the trouble of re-stuffing these cans, or should I aim to preserve what is available? I know that on radio restoration boards they would balk at the idea of leaving a gaping hole in a chassis where a can once was mounted. I think I will do the repair work and get the tv running but save the cans if I ever aim to mount them again.

I plan on hitting up an older electronics store in town in the hopes that they may stock what I am needing. I am pretty doubtful and they will most likely have to order what I need and charge an exorbitant fee.

The values I need are:

c1 150uF @ 150v
c2a 125uF @ 300v
c2b 20uF @ 300v
c2c 20uf @ 50v
c3a 125uF @ 300v
c3b 60uF @ 300v
c3c 40uF @ 50v
c4 4uF @ 50v

A good cap source with reasonable prices is http://justradios.com/ .

Remember, you can go somewhat higher in capacitance and voltage, so, for instance, if someone doesn't have 20mfd/150v, you can use 22mfd/160v.

This model of TV is not a rare treasure, so I doubt anyone would shed tears if you install new caps whatever way is convenient, rather than restuff old cans. I restuff cans for a Veddy Veddy Special item, or if there absolutely isn't enough room for the new caps underneath. For a common, everyday set, who cares?

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

A good cap source with reasonable prices is http://justradios.com/ .

Remember, you can go somewhat higher in capacitance and voltage, so, for instance, if someone doesn't have 20mfd/150v, you can use 22mfd/160v.

This model of TV is not a rare treasure, so I doubt anyone would shed tears if you install new caps whatever way is convenient, rather than restuff old cans. I restuff cans for a Veddy Veddy Special item, or if there absolutely isn't enough room for the new caps underneath. For a common, everyday set, who cares?

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

Yeah I'm aware of some leeway in capacitance, but the stuff on mouser was off but 100 volts or more. And I've never felt bad about increasing the voltage spec on a cap replacement, but I've never felt comfortable reducing it. My sentiments exactly on the cans.

That site only had one capacitor I needed. I feel like I'm making this harder than it should be. The only way I can meet my capacitance values is by increasing the working voltage to 500v.

Which ones couldn't you find at Mouser ? I'm pretty sure they've got you covered. For example, you could use these 150uF @ 400 volt for the 125uF @ 300v caps.

http://www.mouser.com/ProductDetail/Nichicon/UPT2G151MHD/?qs=sGAEpiMZZMtZ1n0r9vR22e0EqeXrojNBtaSWNjInKlY%3d

Yes, with electrolytics it's usually OK to go up (sometimes quite a way up), but never down.

In a pinch, wiring two caps in parallel adds their capacitance together. To keep life simple, I normally do this with two caps rated for the same voltage. (If you use caps with unequal voltage, the voltage rating is the lower of the two.)

For example, you need one 150mfd/150v cap. Wire two 80mfd/160v caps in parallel and you have one 160mfd/160v.

<deleted dumb remark about equalizing resistors>

The article at http://antiqueradio.org/recap.htm has a little more info about combining caps to get particular values.

I find Mouser's filtering system a little confusing at times. If you are too specific when searching for a certain value, you may miss values a bit higher that would work fine.

Phil Nelson

Which ones couldn't you find at Mouser ? I'm pretty sure they've got you covered. For example, you could use these 150uF @ 400 volt for the 125uF @ 300v caps.

http://www.mouser.com/ProductDetail/Nichicon/UPT2G151MHD/?qs=sGAEpiMZZMtZ1n0r9vR22e0EqeXrojNBtaSWNjInKlY%3d

You are right, there are sufficent replacements available from mouser. I was going along with rigid searches on either precise capacitance, or precise working voltages. With a little bit of wiggle roam on both values I have found nearly all my caps. Thanks for making me look where I already knew to look.

...Some people debate at great length whether you should also add parallel resistors to balance the load, but IMHO they are arguing over angels dancing on pinheads.
Phil, balancing (or equalizing) resistors are useful only when putting caps in series. oc

Parallel, series, who cares? :)

Sorry, I was typing too fast (and thinking too slowly). BTW, maybe someday I'll figure out why DuMont used two 80mfd caps in series in the RA-103 power supply. Perhaps it was just cheaper than way. And they did use equalizing resistors, so that's one argument in favor of the pro-equalizer party.

Phil

Nowadays it's probably far less common to have electrolytics in series than it was 'back in the day'. The balancing resistors were a simple safeguard against unequal leakage values in the two caps. It wouldn't take much leakage difference to throw a higher voltage across one cap than the other, potentially exceeding its voltage rating.

I've done caps in series, usually when what I have on hand doesn't have enough voltage, and as a bonus, the capacitence too big. One radio I restored needed 475V filter caps at 50uF, so I used a pair of 100uF at 250V caps in series, and I used 470K resistors across each one to be sure the voltage would divide evenly. The resistors also will bleed off the cap charge when turning the radio off, useful when working on the radio. Oh, the bleedoff isn't very fast, but 20 seconds it's down to safer levels.

Did this in an Admiral I restored as well, plenty of room under the chassis for the extra terminal strips too.