[R-390] R-390A gear train help/advice needed

[Ken Harpur]

Hi Phil,

I have rebuilt two RF decks using Scott's tutorial and there have been no issues...the most time consuming part for me was getting the bandswitch correctly setup. I don't think having a non-functioning gear train would be and issue because if you tear down your RF deck all the way to the start of the reassembly pictures, you're basically starting with a blank canvas...

On my second rebuild I found numerous broken clamps but...prior to the rebuild the deck did actually work. I think there was still just enough clamping force to keep the gears turning as I was tuning around. Maybe on your deck you have some loose or broken clamps and the gears are slipping. Also, I had to remove some washers on some of the cams because someone in the past had installed too many, making some cams very difficult to turn. This meant driving out the small pin, removing required number of washers/spacers, refitting the cam and pressing in the pin. Apart from the two issues I had, following Scott's rebuild instructions and studying the photos makes the rebuild quite a painless experience.

If you have checked and confirmed cam alignment at 7+000 the next thing I would look at are the clamps followed by checking the gears are correctly meshed with their correct counterpart...


Regards,
Ken


On 22/12/2013, at 5:11 AM, "Phil Mills" <pmills7 at comcast.net> wrote:

> Charles, thanks for the link.  It helped me discover a major
> problem right away.  It seems that this radio is 7+xxx all
> the way to the high end of the band and then rolls over
> to 7.000.   Now all I have to do is figure out just how to
> fix this.....    Unfortunately, this very nice rebuild tutorial that
> you pointed me to appears to be based on a properly
> functioning gear train at the start.
> 
> thanks again,
> Phil
> 
> 
> ----- Original Message ----- From: "Charles Steinmetz" <csteinmetz at yandex.com>
> To: "390 list" <r-390 at mailman.qth.net>
> Sent: Saturday, December 21, 2013 11:51 AM
> Subject: Re: [R-390] R-390A gear train help/advice needed
> 
> 
>> Phil wrote:
>> 
>>> Can anyone off advice as to where to look in either the manul or
>>> geartrain itself to resolve the problem?
>> 
>> Scott Seickel's excellent photo tutorial at <<http://militaryradio.com/r390a-rfdeck-geartrain.html>http://militaryradio.com/r390a-rfdeck-geartrain.html> should give you everything you need.
>> 
>> Best regards,
>> 
>> Charles
>> 
>> 
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