Control Cables and RFI

Tue Sep 5 21:12:42 EDT 1995

In a message dated 95-09-05 10:37:21 EDT, maca at maca.sarnoff.com (MACA)
writes:

>	Server Error please resend

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From:	maca at maca.sarnoff.com (MACA)
To:	cq-contest at tgv.com
Date: 95-09-05 10:37:21 EDT

Mail*Link(r) SMTP               Control cables and TVI

In preparing for the Sprint, I wanted to solve a nagging problem with
interference to my VCR.  We're in a covenant-restricted neighborhood, so I
ran balanced feedlines into my attic as the house was being constructed, and
have been sucessfully using an 80M dipole that's on a short pole just above
the roofline.  

During the construction of the house, I took great care to distance the
feedline from any power, phone or CATV cables.  Despite this and numerous
efforts to eliminate the problem at the VCR, I continued to have annoying
interference.  I felt that replacing the open feeders with a good quality
coax would solve the problem.  I would run that along with a shielded control
cable to my homebrew bandswitching tuner, which I planned to place in the
attic close to the antenna.

I was highly disappointed when this fix failed to solve the problem!  I
suspected that I was getting current flow on the outside shield of the coax,
so I placed about ten ferrite sleeves on the distant end of the coax.  This
improved the situation slightly, but the interference persisted.  I
disconnected the tuner from the coax and control cable, and tried using
another manual tuner that didn't require the control cable.  Problem
solved!!!

While I had taken great care to extensively bypass the inner conductors of my
control cable, the shield was acting as return RF path.  Once the control
cable was disconnected, I also noticed that the bandwidth of the antenna
dramatically increased, also indicating that the control cable had been
radiating.

For those of you who work with high power and multiple antenna systems and
multiple control cables, this may just be a blinding flash of the obvious.
 I, however, learned a lot from this experience and intend to provide the
same level of attention to my control cables as I do to my main feedline.
 That means RF choking at the near and distant ends, and, of course, the
normal bypassing efforts.

Maybe this experience may help you solve a nagging interference problem.

73,  Paul, KB8N

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Date: Mon, 4 Sep 1995 10:46:48 -0400
From: PaulKB8N at aol.com
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Subject: Control cables and TVI

>From LBMQ58B at prodigy.com (DOUG KLEIN)  Tue Sep  5 23:59:50 1995
From: LBMQ58B at prodigy.com (DOUG KLEIN) (DOUG KLEIN)
Date: Tue, 05 Sep 1995 18:59:50 EDT
Subject: MRRC Sprint team
Message-ID: <013.00846313.LBMQ58B at prodigy.com>

-- [ From: Doug Klein * EMC.Ver #2.10P ] --

I still have two slots open for the CW sprint this Saturday night)
local time.  Anybody out there without a team want to play on the MRRC
team?  So far we have:

W0CG (WD8AUB op)
K8MR
WD8LLD
NF8R
W3GH
WM4T (KU8E) in rare Kentucky
W8FN
K8CC

Thanks and please E-mail me direct within 48 hours if you want to join
the team.  

Doug WD8AUB  LBMQ58B at PRODIGY.COM

>From oo7 at astro.as.utexas.edu (Derek Wills)  Wed Sep  6 04:29:29 1995
From: oo7 at astro.as.utexas.edu (Derek Wills) (Derek Wills)
Date: Tue, 5 Sep 1995 22:29:29 -0500
Subject: fame for KR0Y

Spots for XR0Y are all over the clusters - in addition to the usual
"what is location?" notes, one on ours says "Is that really KR0Y?"
Well, what's a dit here or there?

Jeff, let us know how many QSL requests you get after the next week -
(for those who don't know, KR0Y is a famous CONTESTer)

Derek Wills (AA5BT, G3NMX)
oo7 at astro.as.utexas.edu 

>From Lee Hiers <0006701840 at mcimail.com>  Wed Sep  6 05:01:00 1995
From: Lee Hiers <0006701840 at mcimail.com> (Lee Hiers)
Date: Tue, 5 Sep 95 23:01 EST
Subject: TS850 keying
Message-ID: <10950906040101/0006701840DC3EM at MCIMAIL.COM>

First, I apologize if this topic is of limited interest to the
CQ-contest reflector users....but then again, I think this is probably
the best resource for this question.

Bob, AA4U is in exile in Indonesia and has asked me to help him with
the following problem:

He has a TS850 which has a built-in keyer and wants to use this with
the keying provision in his computer logger, but cannot parallel the
two...are there any '850 users out there who have figured out how to
make this happen?  Is there some point inside the radio, after the
keyer output where he could parallel the computer keying?  Bob says
that according to Kenwood, it can't be done...

If you have any ideas, please send them directly to Bob (NOT the
reflector!!) at:

Bob AA4U / YB0ASI - Jakarta    (rblumberg at mcimail.com)

as he is not on the reflector due to the high cost of receiving lotsa
reflector messages in Indonesia.

Thanks for the help...

73 de Lee
aa4ga at mcimail.com

>From Dieter Dippel" <dippel at rrze.uni-erlangen.de  Wed Sep  6 10:02:08 1995
From: Dieter Dippel" <dippel at rrze.uni-erlangen.de (Dieter Dippel)
Date: Wed, 6 Sep 1995 09:02:08 MET
Subject: NEW: WAE-LOGS via EMAIL (COMPUSERVE)
Message-ID: <6BE1BFA41D5 at daphne.rrze.uni-erlangen.de>

Please send your logs to: WAE Contest Committee, Box 1126, D-74370 Sersheim, 
                          Germany.

Attention:
There is also an e-mail (compuserve) address available now: 

                      100712,2226 at compuserve.com

or if this syntax doesn't work (dependig on the mailer, you are using ??!! 
pse try:

                      100712.2226 at compuserve.com

The compuserve e-mail address is accessible via INTERNET. 
All payment for mail should be done by the sender otherwise your mail
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Incoming email is checked every day at app. 17...18:00UTC by DL2DN

73, Herb, DL2DN @DB0RBS.#BW.DEU.EU

PS: DL2DN asked me to forward this message to the contest-reflector!

73 de Dieter, DF4RD
(Member of the Bavarian Contest Club)

email: dippel at rrze.uni-erlangen.de
packet:DF4RD at DB0BOX.#BAY.DEU.EU