[Elecraft] k2 ssb question

[Ron D'Eau Claire]

Those spectrograms do NOT look right! You should not be seeing more than
a few dB difference across the spectrum from 400 Hz to over 2000 Hz.
Mine look to have less than 3 dB across that range. 

First, how are you connecting the computer to the rig? Unless you
compensate for the high frequency roll-off in the audio "phones"
circuit, I'd recommend plugging in to the "aux" speaker jack. That would
affect the spectrogram plots, but NOT how the receiver "sounds" of
course. 

You don't mention which "vintage" of K2 you have. There's a BIG
difference between pre S/N 3000 and post S/N 3000 units. The pre S/N
3000 units had very high roll-off on one end of the filters like yours
shows because of a strong 'tilt' in the passband of the second i-f
"cleanup filter" at the output of the i-f amplifier. It's easy to fix
with a few parts that go on the bottom of the r-f board. You can find
the details on the Elecraft web site. Look for the "K2 2nd Stage Xfil
Mod, for 'Flatter' SSB Filter Response". 

K2 with S/N > 3000 have this mod built in. If yours is one of the newer
ones, the circuit might not be working. 

Other possibilities include a bad crystal or two in the filter on the
SSB board. 

Ron AC7AC
K2 # 1289

-----Original Message-----
Hello:

Not sure how to ask, go to:

http://www.agnew.us/da/n4gsd/

and tell me if those spectrograms look right? The radio still doesnt
sound right on receive. went through and check for mistakes, maybe its
right, I cant tell.

-. ....- --. ... -..
Dwight N4GSD
Nuts 4 German Shepherd Dogs!