[Elecraft] Audio Improvements on a K2

[George, W5YR]

While I do not (yet!) own a K2, I had the pleasure of borrowing one for a
couple of weeks recently. While I had it, I ran spectral plots of the band
noise response of the receiver for all modes and all filters. I used the
same procedure and equipment that I used to plot the IF/audio response
curves for the Icom IC-765 and IC-756PRO which may be seen at

				http://www.qth.net/ab4oj

I have assembled these plots into a rather large but informative ZIP file
containing 19 plots which I will be happy to send to anyone who requests
it. It is about 880K in size.

This particular K2 was built by a resident "expert" builder (not me!) and I
am confident that it represents typical if not above average performance.
My subjective impression upon listening to the K2 on SSB with the same
outboard audio mixer, EQ and power amp/speaker system that I use with my
other receivers was that the audio response did sound rather constricted,
probably due to the response function of the crystal filter. 

The lack of low-frequency response seemed to aid intelligibility for weak
signals but made the stronger signals sound somewhat thin. The lack of
high-frequency response reduced the hiss and higher frequency band noise
components, and thereby helped with weaker signals, but again with strong
SSB signals there was a tendency toward a slight muffled sound. 

Please keep in mind that what the plots show is fairly accurate "science;"
what I say it sounded like to me is conpletely subjective and unsupported
by anything scientific.  <:}

73/72/oo, George W5YR - the Yellow Rose of Texas         
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe   
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
Icom IC-756PRO #02121  Kachina 505 DSP  #91900556  Icom IC-765 #02437

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ZOOM wrote:
> 
> Hi All;
> 
> I really like my K2 but would like to improve on the SSB audio.  My K2 is
> unmodified and I would like to hear from the list which  improvements you
> have made to make the K2 sound better in SSB reception.  I have done the
> spectrogram and my K2 has all the options except the RS232 option.  I know
> there are several mods out there for this rig but I only want to do the ones
> that are essential to improve audio.
> 
> My second question is that i am using a radioshack mike and am told my
> transmit audio is too much on the high side.  What mike seems to work well
> with the K2 and give a nice signal?
> I understand the Hiel offered by Elecraft is a good match but also
> interested in hearing about others.  Could the high pitch sound be caused
> also by my set-up?  I use SSBA=2 and SSBC=2-1 with a stoch RS mike cat #
> 21-11720 cb dynamic microphone.
> Anyone using this mike with good success?
> 
> I hope to hear from some of you soon and thank-you for your efforts,
> Robert
> VE3RPF