K3: RFI on pack panel etc.

[Stephen Prior]

I have had no problems with the data modes all fed directly from the sound
card via the rear line in/out sockets, but I have discovered that I have
significant rf getting in (on 17m in particular) when I plug my MD-2 into
the rear mic input socket.  I have no problems whatsoever when I use the
front panel socket.  I have done all modifications as they have been
announced, but I still have this problem.

In reality of course it's only a minor inconvenience as I can use the front
panel socket but nevertheless the issue still exists.

73 Stephen G4SJP
K3 #980




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[Joe Subich, W4TV-4]

> I have had no problems with the data modes all fed directly
> from the sound card via the rear line in/out sockets, but I
> have discovered that I have significant rf getting in (on 17m
> in particular) when I plug my MD-2 into the rear mic input
> socket.

RF sensitivity which changes based on frequency, band, cable
route and/or front/rear panel is an indication of a common
mode RF issue.  Changing cables will often move the problem
to another frequency or band but the solution is to properly
decouple all feedlines as documented by K9YC (and separately
by W1HIS).

See:  http://www.audiosystemsgroup.com/RFI-Ham.pdf and
www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf

73,

   ... Joe, W4TV
 

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Stephen Prior
> Sent: Sunday, November 08, 2009 6:59 AM
> To: elecraft
> Subject: [Elecraft] K3: RFI on pack panel etc.
>
>
> I have had no problems with the data modes all fed directly
> from the sound card via the rear line in/out sockets, but I
> have discovered that I have significant rf getting in (on 17m
> in particular) when I plug my MD-2 into the rear mic input
> socket.  I have no problems whatsoever when I use the front
> panel socket.  I have done all modifications as they have
> been announced, but I still have this problem.
>
> In reality of course it's only a minor inconvenience as I can
> use the front panel socket but nevertheless the issue still exists.
>
> 73 Stephen G4SJP
> K3 #980
>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

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[Stephen Prior]

Many thanks Joe, especially for the W1HIS link, that makes very interesting
reading.

73 Stephen G4SJP


On 08/11/2009 17:55, "Joe Subich, W4TV" <[hidden email]> wrote:

> www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf




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