[Elecraft] K2 IF Amplifier alignment

[Brett gazdzinski]

I don't think I got a great peak on my K2.
I hear you can use the spectrogram and carefully
tune L34 to give a better signal to noise ratio which
does not happen at peak, but on one side of it.
You can only see it with spectrogram.

I don't think my K2 is low on gain, but it is quiet
which sometimes might make one think its low on gain.

There is also the AGC calibration, and s meter
sensitivity which might effect things, or change
your perception.

I have my S meter set how I like it, which
is more sensitive then the manual recommends.
Setting it per the manual has it very stingy.

My homebrew receivers have no RF amplifier,
and are very quiet single conversion tube designs, and
one might assume they are off in the sensitivity department,
but the signal to noise ratio is what counts, as I could
easily copy weak signals that were under the noise level
of sensitive receivers like the R390A and 756 pro.

Other manufacturers might not try very hard to clean
their rigs up as then people might think they are low in gain
without a lot of background noise.
After all, in a GOOD receiver, you should be able to 
hear each electron passing through the chips, boost the gain
enough to hear it roar by....

 
Brett
N2DTS


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Nick Henwood
> Sent: Tuesday, August 07, 2007 5:00 PM
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] K2 IF Amplifier alignment
> 
> Meanwhile back with K2 #5942)....
> I am realigning my K2 (had to tighten up the amp devices anyway)
> I was never very happy with the IF Amp alignment (P64) when I 
> first built it. There does not seem to be a clear peak on L34 
> adjustment - just a general area where it seems to be 
> highest. I am using another rig on LP into a dummy load as a 
> signal source - I can hear the internal 7000 MHz signal but 
> it doesn't seem to peak particularly..
> My one comment about the K2 is that it seems a little short 
> on gain (but OK with the DSP). 
> Do I have a problem with the IF amp alignment or my 
> experience the same as others please? Grateful for any advice 
> and comments (makes a change from K3 chat)
> 73 Nick G3RWF
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