[SignalOne] Re: CX-7 Driver Board

[W2AGN]

On 11 Jan 2003 at 16:22, John Seboldt wrote:

> At 09:59 AM 1/11/03 -0800, you wrote:
> >Well, worked on the CX-7A again today, checking bias, etc. All seemed OK.
> >I had replaced the FET (Q1) on the driver board some time ago, with a
> >3N201, which one of the Newsletters said was a good replacement. Out 
of
> >desperation, I popped in an MPF-102 I had, not expecting it to work.
> >
> >Bingo! I got drive! In fact, a lot of drive. I backed down R-19 to 
about
> >halfway. Checked the signal though, and it's "good" RF, not 
oscillating.
> 
> I wonder if your 3N201 was blown... or (isn't this a 2-gate device?) to 
put 
> it in place of a single-gate MOSFET, you have to tie both gates 
together.
> 
> But interesting that the lowly JFET will work too.
> 
> Hurrah for the troubleshooter!
> 
> John K0JD
> Milwaukee

Yes, it is a 2 gate device, but I tied them together, as was suggested in 
the substitution I read. What was odd was I could inject RF with the 
generator at the input, and I got amplified RF out...But didn't work "in 
circuit." 

Sure working now though. Made a few QSOs and got good quality reports, 
too.

---
+-++-++-++-++-+   John L. Sielke
|W||2||A||G||N|        http://www.w2agn.net [UPDATED]
+-++-++-++-++-+    Ex-K3HLU,TF2WKT,W7JEF,W4MPC,N4JS