Hello Adam,
Swapping the tubes is a good idea, but that do not insure that the 1st Xtal 
oscillator is actually working...
You should try to measure if there is any signal on the V401 plate.
This being said, I do not own a R-392, but it is similar to a R-390/URR in 
architecture.
Do you have a copy of the TM11-858 or the TM11-5820-334-35 ??

73, Jacques, VE2JFE in Montreal

-----Message d'origine-----
De : [email protected] <[email protected]> De la part 
de Adam Morehouse
Envoyé : 2 octobre 2025 13:59
À : R-390 Mailing List <[email protected]>
Objet : Re: [R-390] R-392

Managed to get the V401/V203 tubes out with a little bit of gorilla tape as a 
puller. The silicone puller I bought just slips right off them...

I swapped tubes, no changes. The switch seems to be working fine, when I first 
start playing with this thing, if I tapped the chassis it would click in the 
speaker, like a bad connection, etc. I took the bottom decks out, and dropped 
the front panel and saw nothing obvious poking around. Now that it's back 
together, its gone.

A lot of the tubes do test "low" on my Heathkit TT-1 tube tester (TV-7 in the 
pile of stuff to restore/calibrate).


V401

1.  -.3 / 118k

2.  .01 / 8.4

3.  5.8 / 6.2

4.  11.38 / 10.3

5.  21.9 / 1k

6.  21.9 / 1k

7.  .013 / 8.4

V203

1. 0 / 107k

2. 0 / 3.5k

3. 0 / .3

4. 23.99 / 3.7

5. 10.5v / 8.8M

6. .17 /  OL

7. 23.15 / 2k


On Wed, Oct 1, 2025 at 8:08 PM Adam Morehouse <[email protected]> wrote:

> Hey guys,
>
> Doing a little tinkering between classes (18 credits is awful...). I 
> decided to try out a R-392 that came with a T-195 I bought this summer.
> It's nice and clean inside, no obvious defects - but is completely 
> dead below 8MHz. Any idea where I should start my search when I dig into this?
>
> Thanks for any help or pointers...
>
> Adam
>
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