[Elecraft] The Dummy Load Noise Generator

Mon May 19 00:42:00 2003

Hi Don,

You were spot on, the 680 ohm resistor had gone and taken out the one next
to it. The two amplifying transistors had gone as well.  All replaced and
the noise generator seems to be working well now, although only generating
about S2 at 80m and the signal starts to fall off at 20m.  Plenty enough to
align the filters after I had done the 2nd crystal filter mods, but any
suggestions on why the signal would be down?  I'm tempted to believe that
the K2 S meter is a bit stingy, and it and the AGC are the next things I
need to look at.  I'm quite happy with the shape of the filters now.

Mike
K2 - #2599

----- Original Message ----- 
From: "Don Brown" <[email protected]>
To: "Mike Walkington" <[email protected]>
Cc: "Elecraft Reflector" <[email protected]>
Sent: Friday, May 16, 2003 6:21 AM
Subject: Re: [Elecraft] The Dummy Load Noise Generator

> Hi
>
> I thank this happens more than most people want to admit. I put a warning
in
> the instructions about this but it is still easy to do. It will usually
zap
> the 680 ohm resistor and one or two of the transistors depending on how
many
> watts you fed back into the generator. It is a good idea to set the power
> control to minimum then disconnect the key and/or mike when using the
noise
> generator and stay away from the tune button. Almost any small signal NPN
> transistor will work 2n3904 2n2222 2n4401. After several glasses of some
of
> our fine Texas wine, I find messing about with radios is not a good idea,
> but I have been known to do it anyway. ;-)
>
> Don Brown
> KD5NDB
>
>
> ----- Original Message -----
> From: "Mike Walkington" <[email protected]>
> To: <[email protected]>
> Cc: "Elecraft Reflector" <[email protected]>
> Sent: Thursday, May 15, 2003 10:37 PM
> Subject: [Elecraft] The Dummy Load Noise Generator
>
>
> > Hi Don,
> >
> > One glass of red wine, not enough attention being paid to what I was
doing
> > and suddenly the noise generator goes into service as a dummy load.  An
> > acrid smell, one black resistor, two transistors with small bulges are
the
> > obvious signs of damage.  Has this happened to anyone else?  Before I
pull
> > it apart and see what needs fixing do you want to take a stab at
> suggesting
> > what parts might have survived?  A small quiz!
> >
> > Mike
> > AC7MZ
> >
> >
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