View Full Version : Please help me ID disc type capacitor values.


Tubejunke
09-03-2007, 12:48 AM
I am going soon to purchace what I hope are needed ceramic disc caps for my 59 Zenith I've been stumped with. I have an Electrical Technicians Circuit Digest 1958 schematic for a similar chassis but not the exact one I am working with. Mostly tube changes are what I see which certainly means other component value changes as well.

So I have these reddish brown jewels with yellow markings such as 22.21, 22.24, 22.16, 22.3, and so on. I dont know what this represents. I am concerned with one marked 22.24 should be a 2 section .0047mfd according to the schematic. No voltage rating is given. Who knows for sure. The reading I get out of circuit is .007mfd. on either side. This cap goes to pin 7 of a 6CG7 vertical osc. tube. My problem is little to no vertical sweep as elaborated on in another thread. My chassis is an 18C24Q

If anyone knows the secret to ID'ng these things please chime in. This is weird because through time, trial, and error I am pretty familiar with most types of capacitors and their charicteristics. These discs get skipped over most of the time. Perhaps NOT a good rule of thumb to say they rarely give trouble. I will soon find out, With A Little Help From My Friends........

Thanks in advance!!:thmbsp:

Findm-Keepm
09-04-2007, 11:49 AM
The numbers on the capacitors correspond to the Zenith part number, ie. 22.24 is a Zenith 22-24 (or 022-0024 in the modern Zenith part number form). My Zenith guide merely lists them as Ceramic Discs with no values listed. The 22-21 is apparently also a dual disc - the Zenith parts list shows it as being replaced by a 22-3226 and one other cap, unfortunately truncated.

Others in the low part number range with subs are 22-7 and 22-17 (both are subbed by 22-3748).

Sorry no values, just an explanation of the cryptic "22" numbers.

I've seen only a few of the reddish (Erie) dual caps - most of the duals I see are the pale blue kind, and those have given me trouble - ususally a short in one section.

Cheers,

wa2ise
09-04-2007, 03:21 PM
Do some of these things have resistors inside as well as capacitors? I have a B&W Zenith portable that has vertical issues, and I suspect that one or more of these things have gone off spec.

rulerboyz
09-04-2007, 03:33 PM
If you had the original service manual, you would find out what that part number represents from the parts list. It doesn't apppear to be posted on the internet, from what I can tell. Maybe the following site might have the answer:

http://www.justradios.com/oldtvschematics.html#Z

Findm-Keepm
09-04-2007, 05:41 PM
The set is in Sams 452, Folder 2. I don't have one here - will check with my dear old Dad and see if he has it. If so, I can list values as listed with Sams.

Tubejunke - I noticed you are (barely!) in Virginia, along Rt 58. I'm coming through there early next week - need anything brought from the Norfolk area?
I've got to go to Abingdon and then on to Johnson City, TN to visit relatives.

Cheers,
Brian

Steve K
09-04-2007, 06:25 PM
The values are as follows:

22-3 = .01mfd
22-16 = 470mmf
22-21 = 2 x .001mfd
22-24 = 2 x .0047mfd

Steve

Tubejunke
09-05-2007, 12:43 AM
THANKS Steve! Do you have a schematic or some kind of code breaker info from the manufacturer?

To Brian, thanks for the offer. The only thing I need from up north is over in Maryland. One of our members I hope is saving a 21ZP4 CRT for me if I can ever manage to get up that way. I have grandparents that I really need to see in PA. I just havent had the time or the money for a trip lately. I hate it. Ya need to try to see the old folks as much as possible.

Anyhow, again I apreciate the thought. Just not in need of anything from that area at the moment. If you make the trip regularly let me know and I will make note of it..

Thanks to everyone as I got at least some of the values. I only listed a few because I was hoping that there would be some way to ID the rest my self. Kind of like the crazy bumble bee black caps with the crazy color stripes. I hate them but I can ID them. Not these discs I guess. There is probably a list somewhere by the manufacturer of the component that decodes the # system.

I fail to understand why it has to be a big deal to make it hard to id certain components, especially capacitors. I mean why coudnt they simply print the value and voltage rating?

bgadow
09-05-2007, 11:30 AM
Findm, Tubejunke, if we could find someone who was traveling through my way, maybe heading south down US 13, maybe we could get that crt and some other stuff down there? I think there is someplace on AK especially for posting "pony express" requests, will have to look for it...

Tubejunke
09-05-2007, 10:51 PM
Hi Bryan, glad to know you still have my tube. I wonder if there is a SAFE way of shipping a tube. I used to pack fairly delicate servo motors in expanding foam which basically suspends the item in the air laden foam. Pretty good packing method if done correctly. I dont know any way that I would feel 100% good having my crt in the hands of shippers. I'm sure there is a safe way to move anything if you have enough money. I think the tube manufacturers have special shipping cartons they use.

I wasnt aware of any Pony Express deal here. Sounds interesting....

Tubejunke
09-09-2007, 12:18 AM
Well I replaced the stupid things and got what I expected, NO change. The existing discs pretty much spec'd out with a meter. Still you never know with capacitors for sure. Just a few bucks and a few steps closer to actually replacing every part in the chassis!

This is the most stubborn set I have ever owned! My God, with most sets you kind of get to enjoy them kind of coming back to life. Its exciting. This Zenith is ruthless (useless). The buzz in the sound makes me wonder if some capacitor in the Space Command remote chassis is causing trouble in the main chassis. Perhaps in multipe circuits. Who knows? I do know that if you unplug the remote chassis the main chassis will not come on.

I dont know what to do other than look into this remote chassis as an idea for having some crazy short that I'm not finding causing the TV to go whacky.

I wish someone could direct me to some info on the nature of the Zenith remote system from the 50's