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#1
09-12-2009, 07:15 PM
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Still working on my Sylvania
Hi all seemed to have lost this website as it was down for a while.
I needed to ask the staff a few new questions..hope you can chime in. Sylvania Model is 23M-1 , 23-TUBE B&W Sylvania "Halo-Lite". Chassis # 87111-084-075 and refers to SAMS PHOTOFACT PCB174-1 & 154-12 My past posts also seem to be lost. Question: Few different tubes in the chassis wondered if the were totally wrong? Have 6AX4GTB..should be 6W4GT Have 6CB6A..should be 6BC5 (in 4th video IF amp) Have a horizontal tube from Westinghouse all I can make out is DN6 should be a 6CD6G Can I leave this in or are they wrong? * I see from the SAM that a cap .0005/10K volt is in the HV compartment..should I really go in this compartment or leave it alone and just do caps and electrolylics under the chassis? * The black toilet roll paper tubes on the top (C1,C2,C3) can I leave them be? *Halolight control has two resistors 700 and a 500 Ohms,10watts..should they be replaced? thanks 
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#2
09-12-2009, 09:49 PM
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Quote:
In production change C11 they switched to the 6CB6. I believe either should work, but check the production code on your chassis. Do you still have the schematics I sent you? The 6DN6 was obsoleted before the 6CD6. They must have had one laying around. I'd check the all tubes to make sure they're o.k. But the substitutions seem correct. There are two 0.0005 uF 10,000 volt caps in the HV section. Replace them both. They're bumble bees and are probably bad by now, unless they've already been replaced. There should be two other bumble bees elsewhere in the set that need replacing, unless someone did that already. The schematic location numbers in SAMS is different than in the Factory service manuals, so I can't be sure which caps you mean. But, I'm pretty sure. Unless you have the equipment to properly reform and test them at rated voltage, you should replace them. I kept mine. Sane people don't. They don't live forever. They also will die and take out other components if you power the set up normaly without reforming them first. I have service hints and rationale for the production changes that I didn't include when I scanned the manual for you because they are scattered over many pages with other sets. If you have a specific question I can try to look it up for you. John
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#4
09-12-2009, 10:22 PM
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Thanks Guys!!
I am getting ready to start recaping and took out he halolight switch that was located up front in the console..that was when I saw those two large resistors. One looks crumbly and a bit hollow. * the halolight plugs into the Acme power supply mounted seperate on the side...anything in there I should be digging for... or can I leave that can of worms closed??
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#5
09-12-2009, 10:51 PM
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Quote:
The resistor may be bad. Those are wirewound according to the parts list. The nichrome, or whatever alloy they use, seems to corrode away. At least the ones in my Sylvania did that. There weren't for a halolight, but in the audio section of my receiver. John
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#6
09-13-2009, 10:53 AM
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You know the electrolytics that look like paper tubes on the top of the metal chassis. ...I see posts of guys cutting them open and stuffing them with new caps.
Not sure if I can be successful in that endevor. John I think that your answer was that most people replace them..and if they do not you need to do a soft start to reform them. And hope for the best..did this on a 37 Zenith console radio..work like a charm right now. But I just recaped it and plugged the sucker in the wall..
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#7
09-13-2009, 12:05 PM
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Quote:
By the way, the cardboard on the outside is usually there to protect you because the can is at a high potential. If you don't replace them I'd at least do a soft start with a variac or go through a sequence of light bulbs in series with the line. Leave the HOT (Horizontal Output Tube) out until you finished and are ready to start it normally. I powered up a B&K 1077B analyst. I thought it would be safe to do in standby mode. It turned out that standby mode didn't turn off all the HV. One supply was still active. I heard a "zzzz Bang!" and a resistor started to sizzle. It'll be an easy repair, but if I had started it up softly it would probably be working now. It was especially hard on the electrolytic because it was a solidstate bridge. If there was at least a vacuum tube to warm up, it might also have survived. John
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#8
09-14-2009, 09:59 PM
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Just got a variac to do a soft start when my recapping is completed. As I understand it all I need to do is unplug the top cap to my HO tube. Or if I go into the lytics and replace those..I can just leave everything plugged in...right?
Next question is on my 1953 Sylvania..this is not considered a hot chassis..right? I do not need an isolation transformer?
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#9
09-14-2009, 11:37 PM
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This article has advice about identifying and replacing capacitors.
http://www.antiqueradio.org/recap.htm I recommend replacing all of the electrolytic capacitors in the power supply. They may seem to be OK, or temporarily "re-form," but I have not found them to be safe & reliable to use over the long haul. See Matt's thread "Only a Matter of Time" from yesterday. An original electrolytic worked for over a year, and then POOF with no warning. After you have replaced the power supply electrolytics, you shouldn't need a variac except to bring it up slowly one more time while watching for other fireworks. If you don't see any sparks, smoke, or BZZZT at that stage, you can put away the variac. I don't know offhand whether your TV has a hot chassis ("AC/DC" type power supply). If it has a big heavy transformer connected between the power plug and the power supply electrolytics, then the answer is No. An isolation transformer can help protect you against shocks from ground, but it can't prevent all shocks. If you touch one hand to a high voltage source on your TV and another hand to a low potential on that chassis, you'll get shocked because you just created a direct path for the voltage through your body. You'll get this shock whether or not you use an isolation transformer. Use common sense and avoid touching metal things on the chassis with bare hands when it's powered up (or in the case of a hot chassis, simply plugged into the wall). A good oldtimer's practice is to put one hand in your pocket whenever making voltage measurements or other tests on a live chassis. It's a common beginner's mistake to wire an electrolytic backwards. Pay close attention to the positive (+) and negative (-) connections. Phil Nelson
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#11
09-16-2009, 07:03 PM
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Hi All,
Few more questions..please.. I should be getting my order in the mail soon to recap my 41 Philco radio console and my 53 Sylvania Halolight. But I wanted to lay the tv chassis on it side with the crt covered and buffered with foam. So I can work on the caps in this fashion. I really do not want to take off/out the crt if I do not need to. Any issues with this approuch? keep reading about you guys removing the crt..but I like to leave this be sometimes it can become pandoras box.. Also..what is a crt brightener...it it something you buy and put on the neck of the tube?
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#12
09-16-2009, 09:07 PM
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Make sure that the mounting for the face of the crt is very secure. Usually this will be some sort of metal or cloth strap wrapped around the perimeter. Every one I've seen with this type of mounting was okay, but you need to be sure. You will want to be very careful while leaning it over, especially the first time. Sometimes they are "naturally balanced" and will just rest there on their side, but other times they are more awkward and you will need cushioning of some sort to shim them in place while you work. On sets where they crt is not attached to the chassis, well, that is another thing entirely. I don't like doing that unless absolutely neccesary.
The crt brightener plugs in between the crt socket and the crt plug. The circuitry is contained in a little cardboard tube. Basically just a small transformer in there that raises the filament voltage. They can hasten the demise of a crt, but if it is on the way out anyway it will buy you some additional time. Used/NOS brighteners are not hard to find. I can probably come up with a spare.
__________________
Bryan
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#13
09-17-2009, 07:10 AM
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The Sylvanias are usually clamped pretty well. I believe his has a rod on each side of the crt that extends up to a strap across the top. In their service info book they show a similar set on its side.
Check the strap though. I moved a Sonora and it turned out the strap was loose. I was lucky and nothing bad happened. The method used to fasten the strap on the Sonora wasn't very secure either. John
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#14
09-21-2009, 09:35 AM
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Just talked to Radio Daze and they do not carry the caps needed for my HV compartment.
I need two(2) .0005/10K volts caps. anyone have a few to sell me. JOHN also mentioed there were tow more in the chassis (bumble bees) that needed replacing..does anyone know the ones mentioned? And does anyone have a few of these to sell me?? Thanks!
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#15
09-21-2009, 11:05 AM
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Quote:
www.justradios.com carries the caps you need. They're listed as 0.00047uF(470pF)/15kv. John
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