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

The 6AX4GTB is fine. It has higher PIV and peak current ratings than the 6W4.

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

Staff?

The resistors, check them. They see a hard life so they might be bad. No way to know without testing. Or if you can get them easily, replace them.

John

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??

Yeah, I'd leave the supply alone. I think that's just a transformer.

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

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..

Re stuffing them is for the ultimate in keeping it looking authentic. There is often room under the chassis for modern electrolytics and then you can just disconnect the cans.

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

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?

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

It isn't a "hot" chassis. You have a power transformer.

John

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?

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.

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

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!

The two you said that you need are the bumblebees.

www.justradios.com carries the caps you need. They're listed as 0.00047uF(470pF)/15kv.

John

I tried to find the old HV cap I replaced, but I guess I threw it away because it was leaking oil. I wanted to post a photo for you.

It looks just like any other bumblebee except that it's much larger.

I wonder how many sets used these in the HV section. I haven't worked on that many sets, but the other models I've seen used either doorknobs or plain paper for HV.

John

Thanks for looking John!!
Have not received by cap order yet from Radio Daze.
But when I start to dig I know I will have an additional list or order to place and so I will wait to oreder these two caps for the HV section. So to be clear..these are two dog bone paper caps located in the ceramic cage? right?
Also does anyone know of the other two high voltage caps that are in this set that need replacement?

Could you take a photo of the dog bone paper caps you're referring to? I'm a bit confused.

When you ask about the other two, are you asking about finding a supplier for them, or if there are two more that you need to replace?

John

Caps of that voltage are usually Ceramic, are you sure they're bad?

I have (somewhere) some ceramic .001@10,000 they worked good in Horiz section of the Motorola VT-71 sets, I could probably dig them up if you need them.

Sylvania used oil filled paper caps. The one in my set was actually a bumblebee and it has the same part number as in his set so I assumed it would be the same. The part list for his set also refers to it as a molded paper capacitor.

I used the 15KV 470pF film cap from justradios because it was about the same physical size and was easy to replace.

John

I'll send you a different scan tomorrow that has the complete part list. I think I sent you Wallace's which only gives a partial list.

John

Sorry John..beginers do not know all of the language...
I will just go back a little..what I ment by ceramic was in the HV section pictured. Are the two paper capacitors inside this(as you can see white ceramic block) cage?
And before I was asking about the other two paper caps you mentioned in your previuos response about another two 0.0005/10KV caps located elsewhere in the chassis. I was wondering if anyone knew where they were?
Here is also a picture of one of the three paper rolls that needed to be restuffed.
I was wondering if it was easier to solder under the chassis?
And I was looking for some pictures of how other did this chore?
Thanks fao all your patience and time in responding!!

Yes, it's definitely easier to solder them under the chassis. That's how I was doing it until recently when I saw others re-stuffing them. I asked some questions, bought some tools and practiced on a few old caps I had lying around. Now that I've got the hang of it, I'll never go back :)

The cardboard cover ones you've got are easier than the bare metal ones because you can hide the cut you'll be making. Here's my current technique:

1. Make careful notes of the capacitor wiring then remove it from the chassis.

2. Remove the cardboard tube. If it's stuck on tight, I heat it up using a heat gun or bake it in the oven on low heat for a few minutes.

3. Once it's off, clean the goop off the can with lacquer or paint thinner.

4. Cut the can open near the base with a dremel tool and cutoff wheel.

5. Carefully pull the can open using some heat if necessary.

6. Unroll the old capacitor foil to expose the electrodes and clip them off near the base.

7. Drill a tiny hole near each terminal and one more for the ground near the outer edge.

8. Arrange the new caps so they'll fit inside then can and solder them in.

9. Remount the capacitor and get the set working.

10. Finally, glue the can back on with a little epoxy and slip the cardboard tube back over.

Yeah, it's a lot of work!

I've got some to do in a few days. Maybe I'll record a video if you're interested.

Bob

That's called the High Voltage Scanning Assembly. In the second photo the side that you are looking has the terminals and is has a bakelite cover. Under that are a couple of resistors and the two 5642 HV Rectifier tubes. On the other side of the ceramic inside the cage are the two 0.0005uF 10KV capacitors. You have to remove the cage to get at them. The SAMS probably tells you how to do that. Otherwise you'll have to look at it and figure out how to remove it. I don't have this particular set so I'm limited in the advice I can give. It appears that it is held on by tabs in two slots. You may just need to spread the cage out past the tabs and slide it off.

This is an area that may hold charge for quite some time and can be dangerous. I doubt that the original caps can hold charge for long though. If you discharge the CRT anode lead you'll probably be o.k.

I've forgotten what I actually did send to you. Could you tell the the page numbers that are in the pdf file? That'll let me know if I sent everything and if I used the factory service book or the Wallace's.

These are the only two 10KV capacitors in your set.

John

Part List
 

I've emailed you a complete part list and a better document this time. It's from the factory service manual. Sorry about the incomplete list. It must have made ordering caps difficult.

John

Thanks guys for your help.
Bob if you can post some pictures of how you stuff the cans..it will be very interesting for all to see. The paper tubes seem to be riveted on to the metal chassis.Guess you need to dremel them off or drill them out.

Take a close look - those might be mounting plates for the capacitors that are riveted on. The capacitors are usual attached via four metal lugs that are twisted through slots. Like these.

Check out zenithfan1's thread here for a tutorial.

I've got some photos here.

Maybe I'll make a more detailed step-by-step with my next project.

Schematics for 23M-1
 

I thought this might be useful to others.

John

Finally recieved my caps from radio days..they looked at the schematics and sent me a total of 33 caps. And 13 of them are electrolytics. Thought there would be more than 33 of them..does that sound right?
Still trying to figure out how to stuff the paper cans.
I have to do three of them C1,C2 and C3.
Looking at the chart for say C1 ..I have to put in a 40mf/350v ( have a 47mf/450v) also an 80mf/350 (have a 100mf/450v) inside the can.
But I must be blind..well I am using two diff pairs of glasses now..but I can not find the C1 item on the schemeatics. Can someone help me figure out how to attack this problem?
Here is the underside two together are C1 and C2 , the one alone is the C3 on the schematic. Those tangs you twist to hol it in place..those are ground right?

According to your schematic 156 and 157 are in one can, that would be the two section one shown on the right side of your first picture, those are 40 & 80 MFD @ 350v
You can use a 450 volt capacitor in place of a 350 but they are bigger and that can cause a problem when you are restuffing.

Right next to the lugs on the bottom is a logo, a half circle for the 40 and a triangle for the 80, you can see those on the schematic, also the values should be stamped in the paper sleeve of the capacitor.

The twisted lugs are the ground (negative) for the capacitor, however in that case the Cap ground is not the same as the chassis ground, that's why they are mounted in a Phenolic washer, matters not as long as you connect the - terminal of your new cap to the ground lug and the + to the lugs in the center.

Not sure about C1, C2 or C3. I see C155 - C158 on John's schematic. Looks like 155-157 are in one can and C158 is on it's own.

The tangs are the common lead for the capacitor not necessarily ground. According to John's schematic they are connected to the -135V bus. That's why those caps are mounted on insulating wafers rather than directly to the chassis.

I think you'd have an easier time leaving the old caps in place and leave the leads going to the tangs. Clip the wires going to the + lugs for each cap section and solder them to you new caps. Solder the negative leads of the new caps to the old tangs.

At least until the set is working - then maybe go back and re-stuff them if you want to.

It's also a lot easier to just look at what's marked on the cans and go with that rather than trying to figure out what goes where from the schematic, this also eliminates any errors from misprints.

Eric, the part locations you gave are correct for the schematics I gave him. However, I think he also has a Sams, in which case they're labeled C1..C3 on the Sams. I'm not sure which one he is looking at.

If he looks at the one that I posted then your explanation should work for him.

Mick, 33 caps is about right. If they gave you one for C196, on the schematic I gave you, I'd leave it alone. It's polystyrene and should be o.k. If you replace it you'll have to readjust the horizontal frequency and phase.

John

C158 is in the same can as C178, C210, C181. How's that for confusing. Sylvania never seemed to like C1A,B,C,D You need to look at the part list to figure out which ones are in which can.

John

Thanks John - that is confusing!

sorry gents..I was looking at the SAMS and going back and forth..any was confused.
I will have another look tomorrow as it is late. Appreciate all your help..and I am taking your advice (John)on the C196..have that sucker highlighted in yellow.
many thanks on that!

Well I went a replaced the the .015mF in the horizontal tuner by accident.
C196 was not on the SAMS..so I goofed again.
This looked just like the rest of the waxy caps as I was going along.
The next day I relized what I had done..so I soldered the old cap back in.
Do you think that since I cut it out and put it back that I will still have to readjust all of the issues that John mentioned?
If so.. should I just put the new one back??
I was not thinking and had a different thought in my mind as to what the polystyrene cap would look like.
Not sure how to make these HF & phase adjustements if they arise..so I bet I will be posting that question in the future..if the sucker actually lights up.

It probably won't matter. You may have to do a slight readjustment of the horizontal frequency at most. It's just that the replacement could be much different than the original polystyrene in value.

John

Hi John,
Do you mean that it wont matter in the fact that I cut out and put back in the old wax cap?
Or I wont matter ..if I replace the old with the new cap?

Is the HF adjustment the little screw comming out of the back of the chassis?

I meant that it won't matter that you took the old cap out and put it back in. I'm reluctant to refer to it as "old wax cap" because that sounds like paper to people when this one is polystyrene.

Yes, it's next to the size switch. That's the top core which is labeled horizontal hold on the diagram, and the bottom core is on the inside and that's the phasing.

When you get to the point where you need to touch up the horizontal hold you want to remove the 6AL5 discriminator tube and adjust the hold until the picture is nearly normal and moves slowly across the screen. Then when you replace the 6AL5 it should lock in and be stable as soon as the tube warms up. That 6AL5 has a 4.5 ohm resistor in series with it's heater. It may be bad or at least increased in value. You should probably check it. It's meant to keep the 6AL5 from heating up as quickly as the other tubes and gives the horizontal a chance to get close to the proper frequency. Otherwise it could lock in on a harmonic. Not likely, but possible.

John