[R-390] Dumb Mechanical Alignment question

[Barry]

I think that validates Jacques' diagnosis.  Are you sure you need to remove the deck?  I think so because I don't think you can see the alignment lines for the cams but maybe you can see those and set them without removing the deck.  I may spin mine around and see for myself later today.

Remember that the MC change knob will also rotate the other cams so it may not be all the cams that have moved and you might find/adjust/tighten just one.  

Like Jacques said, if it is that far out of alignment cam-wise (or transformer-wise), then likely you can't hear much of anything.

Keep us posted.

Barry - N4BUQ


> Aw nuts, mechanical alignment! As I wiggle the MHZ shaft off the detent the
> station I am listening to gets MUCH louder!! I thought I was careful about the
> detent at 7.000+ had the RF bandswitch on Geneva/giant bandswitch for each MHz
> dead on; I guess not. Off she comes again.
> Sent from my iPhone
> 
>> On Jul 16, 2026, at 12:05 PM, Jacques Fortin via R-390 <r-390 at mailman.qth.net>
>> wrote:
>> 
>> Paul, Barry:
>> It's the alignment...
>> Paul cannot know if it was properly aligned before.
>> IF the position of the cams is dead-on correct at 07+000 NOW, it is possible
>> that it was "off" before.
>> The RF deck alignment is a long and tedious process, but it cannot give proper
>> results if the mechanical part is/was "off", even slightly.
>> The global "play" around the theorical center adjustment frequency (when it is
>> properly adjusted) is not more than about 50kHz wide, so it is easy to be "off
>> adjustment" on any band.
>> If the BCB band works OK, it is already good: the 17MHz oscillator is working !
>> But even with the global tuning completely "off", it is really hard to not
>> receive a 50kW AM station...
>> 
>> 73, Jacques, VE2JFE in Montreal
>> 
>> -----Message d'origine-----
>> De : r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> De la part de
>> Barry via R-390
>> Envoyé : 16 juillet 2026 11:23
>> À : Barry <n4buq at knology.net>
>> Cc : R-390 Mailing List <r-390 at mailman.qth.net>
>> Objet : Re: [R-390] Dumb Mechanical Alignment question
>> 
>> It occurred to me that it's apparenty working on TWO bands.  It could still be
>> the oscillators.  Can you hear the calibrator on any of the other bands?
>> 
>> Barry - N4BUQ
>> 
>>> Very good!  If it's working on one band (BCB), then it likely is not
>>> the PTO.  I think I'd tend to check the crystal oscillator(s).
>>> 
>>> 73,
>>> Barry - N4BUQ
>>> 
>>>> Got her all back together. The good news is it picks up my super loud
>>>> local AM stations about where they should be on the dial! The bad
>>>> news is that’s basically the  ONLY stations it gets!!! Seems to have lost all
>>>> sensitivity.
>>>> I’ll work on it; I doubt it’s the RF deck since stations come in at
>>>> 950 and
>>>> 1260 and 1500 kc as they “should”. Will check PTO and tubes.
>>>> Sent from my iPhone
>>>> 
>>>>> On Jul 16, 2026, at 7:27 AM, Paul Roche <rochep at comcast.net> wrote:
>>>>> 
>>>>> Thanks so much, I might get it back together today and will give it a shot!
>>>>> Sent from my iPhone
>>>>> 
>>>>>> On Jul 15, 2026, at 10:50 PM, Jacques Fortin <jacques.f at videotron.ca> wrote:
>>>>>> 
>>>>>> Hi Paul,
>>>>>> 
>>>>>> When the counters are at 07+000 the PTO output have to be at 2.455 Mhz.
>>>>>> The PTO output change "in reverse" relating to the tuned frequency:
>>>>>> if the shaft is turned clockwise, the outpu
> 
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