[R-390] Dumb Mechanical Alignment question

[Renee K6FSB]

I thought I saw a paper by Larry a while back on osc levels and I did 
have a copy. My memory still good...it is attached.
Renée

On 7/16/26 1:48 PM, Renee K6FSB wrote:
> Paul-
> That wrapping a coil around the osc tubes is one way and works, also 
> you can check directly both 1st and 2nd , the 1st which directly 
> accessed at (IIRC for r390) J421/P221 and the 2nd is J422/P222, if you 
> are having freq adj issues in the osc deck the caps are also switched 
> independently of crystals so another potential spot and that is 
> internal osc deck alignment and is pretty good and generally not an 
> issue however....
> there is also test spots at the grid of each mixer ( IIRC) E209 and 
> E210......I need go look a the manual it has been a while for both 390 
> and 390A.
> i know there is also a spot on the 1st mixer grid for the input signal 
> E20? after the RF front end.
> remember at the grid of the mixer you are looking backwards to 
> previous stage, injection is on the cathode. do look a the schematics 
> to make sure
> i gave correct locations
> HTH
> Renée
>
> On 7/16/26 11:58 AM, Paul Roche wrote:
>> Renee, I think you are right. Unfortunately I can’t seee that now. 
>> How do I check that the Osc is working on each band, listen 455kc up 
>> from each MHz position with a coil around Osc tube?
>>
>> Playing just now with sig generator input, took about 1 VOLT output 
>> to hear signal at 2900 or 3900 kc!! That’s pretty deaf. I need to 
>> check tubes, it worked pretty well 2 weeks ago; sounds mechanical to me.
>> Sent from my iPhone
>>
>>> On Jul 16, 2026, at 2:45 PM, Renee K6FSB <k6fsb.1 at gmail.com> wrote:
>>>
>>>  There is a possibility that the osc contacts are not quite in sync 
>>> for ALL bands. in other words poor contact or slightly off the contacts.
>>> you may have to massage / move slightly to have good contact over 
>>> all positions, the orientation of that gear may need to be 
>>> shifted...it does not take much. check that the osc works in all 
>>> positions before doing anything.
>>> Renée
>>>
>>> On 7/16/26 11:13 AM, Fred Moore via R-390 wrote:
>>>> Paul,
>>>>
>>>> Thanks for bringing up this thread.  I have exactly that problem with an RF
>>>> unit here.  I rock the MHz knob.  Signal gets a lot better.  To me, that looks
>>>> first like the basic mechanical alignment.  If someone hasn't messed with the
>>>> electrical alignment, everything might fall into place.  Then check
>>>> sensitivity on each MHz to confirm the electrical part.
>>>>
>>>> On the R-390 the painted lines are to the rear and may require the removal of
>>>> the osc unit to see them.  On the R-390A the lines are on the front of the RF
>>>> unit (if no one accidentally cleaned them off).
>>>>
>>>> -Fred
>>>>
>>>>    
>>>>
>>>>
>>>>
>>>>
>

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