[R-390] unstable BFO note on R-390A

[Joe Foley]

--- Bob Young <youngbob53 at msn.com> wrote:

> I use the BFO frequently to zero beat the carriers
> on BCB. It is off by 
> maybe 200 CPS for one thing after moving the BFO
> knob as much as it could go 
> to one side,
+++++++++
No, maybe not.  Have you adjusted the frequency
readout with the ZERO ADJUST knob yet?  It disconnects
the gears from the KC CHANGE knob, that may be where
your 200 CPS error is coming from.



 is this an easy fix to align the BFO?
> Also although I feel no 
> backlash it is jumpy when tuning with it on. If I
> move the tuning knob up 
> and down the BFO will jump to differing frequencies
> and sometimes stay off 
> center. 
+++++++++
Is there a spring on the Oldham coupler on the PTO
shaft?  While you're looking in there clean the flat
pointed spring that rides on the PTO shaft, but don't
oil it, leave it so it can make an electrical contact
to the shaft.


One of the springs on the split gear is
> shorter than the other, 
> could this cause this problem, or is this more
> indicative of worn gears 
> maybe? Any other ideas? thanks, it is worse when
> warm.
++++
Make sure you do this after at least a one-hour warm
up so everything is as stable as it can be.  Some
frequency change while warming up is,.......
acceptable, ... I guess.  Ok, its tubular, it happens
with tubes!

Joe



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