[TMC] Early Version of TMC GSB-1

[Roy Morgan]

On Jul 28, 2009, at 12:40 AM, triodes at optonline.net wrote:

> I recently acquired a virtually as-new GSB-1 SSB Converter....  
> significantly different from the first GSB-1 that I had.

Bruce,

I think  your GSB-1 is a hoax and  you should get rid of it as soon as  
possible.  Just send it to me and I'll make a thorough analysis of the  
thing (which may take quite some time to complete).

<Spoof mode OFF>

I have a GSB-1 but it's not like the one you just got.

If  yours is in good condition,  you won't be tempted to refinish the  
front panel.  But if you ever do, here's an odd thing that happened to  
me: I was overhauling a GPR-90 and GSB-1. The GSB-1 panel had been  
refinished, front and back.  The thing did not align correctly, and  
drifted off frequency when  your hand approached the panel, but only  
on Lower Sideband.  I traced the trouble to this:  The rear of the  
panel must make good electrical contact with the points it mounts to  
the chassis.  The side band switch depends on the capacity of the  
panel to the chassis and good grounding to make the local oscillator  
shift frequency correctly.  The switched-in capacitance to lower the  
LO frequency is grounded at the front panel by the switch.   So I had  
to sand-paper the mounting points and make sure the grounding was  
right.. then it aligned and ran correctly.

Roy

Roy Morgan
k1lky at earthlink.net
529 Cobb St.
Groton NY, 13073
Home: 607-898-3607
Cell: 301-928-7794