[Elecraft] K3: RFI on pack panel etc.

[Joe Subich, W4TV]

> 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: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] 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
> 
> 
> 
> 
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