[Elecraft] RS232 Noise

[Radio Amateur N5GE]

On Wed, 22 Apr 2009 19:11:51 -0400, "Mike Harris"
<mike.harris at horizon.co.fk> wrote:

Being concerned by your report, I checked my K3 #806 and did not
experience the symptom you describe.

Tom, N5GE
K3 #806, K3 #1055
XV144, XV432
W1 and other small kits.
http://www.n5ge.com

>G'day,
>
>Just in case anyone is interested.
>
>Today I was investigating the effectiveness on a local 6m low level signal 
>of the various combinations of NO PREAMP, K3 PREAMP ONLY, PR6 ONLY, K3 
>PREAMP + PR6 in preparation for a 6m EME test.
>
>All was as expected then I turned on the PC.  With the two preamps in line 
>there was a 1-2 S-point increase in background noise (SSB bandwidth). 
>This extra noise vanished when I removed the "RS232" cable from the K3. 
>The cable is actually the one I made up for the K2.
>
>Touching the shell of the connector to the K3 shell didn't restore the 
>noise, only when actually inserting the pins did it come back.
>
>No noise being carried on the two audio leads to/from the PC so no big 
>deal the disconnect the RS232 during the moon run.
>
>No further investigations to date.
>
>Regards,
>
>Mike VP8NO 
>
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