[R-390] Bandswitch Gearing Problem

[Roy Morgan]

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