Zenith 7h822-z tubes not lit

[init4fun]

Originally Posted by Tennangler

I will try to find the correct tube.
Which one is the filter capacitor?

Yes, it's far easier to get the right tube than to try to rewire the socket.

The filter caps are "C20" and "C21" in the Nostalgia Air schematic I Posted a link to in Post #2 of your thread Rated at 40 and 80 MFD & 150 volts. 160 volts will be the modern replacements.

[Electronic M]

Originally Posted by init4fun

Yes, it's far easier to get the right tube than to try to rewire the socket.

The filter caps are "C20" and "C21" in the Nostalgia Air schematic I Posted a link to in Post #2 of your thread Rated at 40 and 80 MFD & 150 volts. 160 volts will be the modern replacements.

47 and 82uF are the modern replacement capacitance...

[init4fun]

Originally Posted by Electronic M

47 and 82uF are the modern replacement capacitance...

Yep, thought I typed that in there along with the 160 volts, but musta missed it......

[Tennangler]

I was able to get a 35B5 tube. The FM radio now works. I had to re string the tuning knob and deoxit the fm/am selector.
The am radio is still not picking up a station (any ideas)? The speaker paper is torn. Also there is a pot that sticks out the side of the cabinet. What is that for?
James

[Tennangler]

I am trying to send a photo of the pot that sticks out the side of the cabinet. I get a message the file is to big. Dont know how to size it smsller.

[old_tv_nut]

Irfanview is a handy free program for resizing and such.
https://www.irfanview.com/

[init4fun]

Originally Posted by Tennangler

I am trying to send a photo of the pot that sticks out the side of the cabinet. I get a message the file is to big. Dont know how to size it smsller.

Hi Tennangler,

At 20:15 in this UTube video (not my video, just something I found for you on a search of "Zenith 7H822-Z") you will see that it is the Tone control

https://www.youtube.com/watch?v=Zd5VACdiJ-c

[init4fun]

An interesting side note here......

I looked till my eyes were blurry at the Nostalgia Air schematic I posted in post #2, looking for the tone control and couldn't find it

Come to find out, that schematic only covered the 7H822 and not the 7H822-Z. So of course, when I did find the "changes" page regarding the -Z variant, sure enough there is the tone control (lower RH side of the page)

Disregard the one error in the revised drawing; they show the Grid & Cathode tied together, this is wrong, the cathode is grounded in the -Z model just as it is in the 7H822 and is NOT (absolutely couldn't be) connected to the control grid as the mistake shows it to be ....

http://www.nostalgiaair.org/PagesByM...0/M0025310.pdf

You have my apology if the original schematic I found, and not the updated one, caused you any uncertainty as to what the "mystery" control is.....

[Tennangler]

I was able to attach the tone control pot per the schematic. I dont really hear a difference when I turn it. That's ok, I just wanted the hole in the case filled. The radio is reassembled and working fairly well (weak FM).
Thanks for all the instruction.
James