[R-390] Bandswitch Gearing Problem

[Cecil Acuff]

Maybe working against the zero adjust mechanism?

Just a wild guess...

Cecil
----- Original Message ----- 
From: "Roy Morgan" <k1lky at earthlink.net>
To: "Mike Hardie" <mike46 at shaw.ca>
Cc: <r-390 at mailman.qth.net>
Sent: Sunday, May 11, 2008 9:19 PM
Subject: Re: [R-390] Bandswitch Gearing Problem


> 
> On May 11, 2008, at 4:05 PM, Mike Hardie wrote:
> 
>> After cleaning the geartrain and re-assembling it there is  
>> excessive "play" in the gears that drive the bandswitch shaft.
> 
> Mike,
> 
> It might help to know if this is an R-390A or an R-390/URR.
> 
>> The silver colored gear that has a ball bearing in a hole, and the  
>> brass colored gear right next to it, don't move together when it  
>> seems like they should, there's a couple of gear teeth "lag".
> 
> It sounds like a loose shaft clamp.  (The other source of play in  
> gears is not having loading in the anti-backlash gears.)  Watch the  
> shafts and the gears on them very carefully as you create this two  
> tooth "lag".  Use a magnifying glass if you can and  need to.  You  
> may well find a gear that's not being driven solidly by the shaft  
> it's on.
> 
>> The radio was obtained in very poor condition and hasn't been  
>> operational yet.  Is this an excessive wear problem, or has  
>> something been re-assembled incorrectly?
> 
> Lots of wear in gears can make for play, but the anti-backlash gears  
> are placed where they are to prevent this.
> 
> Roy
> 
> 
> 
> Roy Morgan
> k1lky at earthlink.net
> Lovettsville, VA 20180
> 
> 
> 
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