[RRDXA] RFI

[Juergen Henneke, DF1DX]

Guten Tag,

aus gegebenem Anlass einige Hinweise zur Entstörung
von der microHAM-Liste.

73 Jürgen, DF1DX

[snip] ----------------------------------

b. Re: MK2R+ and 20m Interaction
     Posted by: "Joe Subich, W4TV" w4tv at microham-usa.com k4ik
     Date: Sun Oct 28, 2007 10:47 pm ((PDT))

If you have a problem that is related to transmitting on
one band, I would look for common mode RF issues ("hot"
feedline) and/or radiated RF on that band.  The most
common issue is a hot feedline that places MK2R at the
"wrong" place.

I strongly recommend the writings by W1HIS and W9YC on
common mode chokes and RFI suppression.

W9YC:  www.audiosystemsgroup.com/publish.htm
        www.audiosystemsgroup.com/SAC0305Ferrites.pdf
        www.audiosystemsgroup.com/RFI-Ham.pdf
        www.audiosystemsgroup.com/CoaxChokes.pdf

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

73,

    ... Joe Subich, W4TV
        microHAM America
        http://www.microHAM-USA.com
        http://groups.yahoo.com/group/microHAM
        support at microham.com


> > -----Original Message-----
> > From: microHAM at yahoogroups.com
> > [mailto:microHAM at yahoogroups.com] On Behalf Of py2ny
> > Sent: Sunday, October 28, 2007 7:59 PM
> > To: microHAM at yahoogroups.com
> > Subject: [microHAM] MK2R+ and 20m Interaction
> >
> >
> > Good Evening...
> > I am suffering a lot on this CQ WW SSB !! I have
> > MK2R+ with a FT1000 Field plus Alpha 91B
> > with no more than 500/600w all the time.
> > I have no reason, but it's impossible to work
> > with this setup on 20m with more than 200w...
> > A very strange interaction specially while
> > using ProSet Heil HC-4 (boomset) and MK2R,
> > is happening, only on 20m...
> > You can go to 10m, use everything there with
> > no problem, and then to 20m. After few minutes,
> > transmissions seems to be overloaded and some
> > times (VOX operation) the TX stay transmiting
> > after you stop to talk, with noise into in the
> > microphone...
> > I have NO PROBLEM if I take of 8pin cable
> > in front of the radio and attach there, directly,
> > Proset, but I loose DVK...
> > If you have any hints about that let me know:
> > grounding MK2R box? Changing something
> > in the cables?
> > Only on 20m !!
> > Thanks in advance...
> > Vitor PY2NY