[SignalOne] CX11A warm up issue

[Fred]

Bob asked me to post this info for him.
This has been a problem with most, if not all CX11s. 
One of my CX11As drifts down 500Hz.
73 de
K5OG
Fred
www.k5og.com

Subject:
CX11A Warm Up Drift
From:
RZaepfel at aol.com
Date:
Mon, 23 Jul 2007 10:23:53 EDT

To:
signalone at mailman.qth.net


Hello List,

 

I've done some good investigative work and a little basic engineering on 
this problem. I'll produce a lengthy report in a couple days, but for 
now here's how my CX11A is  behaving:

 

Before: warm up drift of about 400 Hz starting with the readout at 
XXXX.4 and slowly moving downward. My radio took over two hours to come 
to rest.

 

After: warm up drift of about 60 Hz starting with the readout at XXXX.06 
(interpolated) and moving downward. Readout is in registration in about 
six minutes.

 

Most of the solution is to heat the entire BFO box from the inside and 
keep it warm all the time.

 

Bob Zaepfel K4HJF

Manassas, VA