On Sat, 7 Jul 2001 17:38:17 EDT, Adam1coree@aol.com wrote:
>Hi Carl i had the same problem .I had to much rf in the shack.I had
>about 30
>extra feet of coax in the back yard just laying on the ground.I cut
>the extra
>coax off and my problem was solved.I hope this is of some help to
>you.
>
> Adam
>
For all of you gave suggestions, please accept my sincere thanks! I
think I've fixed it, but I found out some strange things in the
process. The problem did come back and I isolated it to the new
speaker wire. First I tried a shielded cable and that only made the
problem worse. I then shortened the original "speaker wire" twin
lead and the problem stopped. The strange thing, though, is that if
I used an RF choke (RS 273-104) on the speaker wire the problem would
return. It seems that my best solution is the shorter speaker wire
without shielding and without a choke.
The problem first manifest itself on 20M. After installing the
shorter speaker wire, I tried all the other bands and discovered that
the problem was still present on 15M. I solved this part of the
equation by slipping a ferrite filter (RS 273-105C) over the cable
going from the remote control unit to the rig. The placement was
critical. If the filter was too close to the rig or too close to the
remote unit it wasn't effective. It worked when it was placed about
halfway along the cable.
At this point, my Jupiter seems to be operating just like it did
before I added the external speaker. Little did I know that this
shack improvement project (much better speaker, with transformer
isolation, etc.) would cause such an unintended consequence. Perhaps
one of you who has an EE background can explain to me why RF chokes
on the speaker wire would bring the problem back after I solved it by
shortening the wire. Also, why would shielded cable be worse than
zip-cord type speaker wire?
Again, I appreciate all of your help. You don't think TT can add
better shielding to the rig as part of the next firmware download, do
you! ; - )
73
Carl
================================
Carl J. Denbow
KA8JXG
17 Coventry Lane
Athens, Ohio USA
EM89WH
Working on WAS, DXCC and
World Radio's "31 on 31" (PSK31) Award
================================
Message sent from ka8jxg@callsign.net on 07/07/2001
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