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G0CJM > AERIAL 08.02.08 14:01l 64 Lines 3275 Bytes #999 (0) @ EU
BID : AD0151G0CJM
Read: GUEST
Subj: Coax traps?
Path: IZ3LSV<IW2OHX<OE6XPE<DB0RES<ON0AR<GB7CIP<GB7IMK
Sent: 080207/1407Z @:GB7IMK.#43.GBR.EU #:13239 [Via TCP/IP] $:AD0151G0CJM
From: G0CJM@GB7IMK.#43.GBR.EU
To : AERIAL@EU
Since the 80s i have been interested in wire aerials and improving them
and using them covertly. Quite frankly, there is absolutely no need
whatsoever to draw attention to our work, we are after all said and done
the unpaid scientists into the best way to get a signal from A to B.
Years ago in Fareham almost all my aerials were wire. At that time i was
near to Fareham creek which had very obvious advantages when the bassin
were full and i could run out a copper wire for top band no problem and
with little hassle from neighbours as they were nearly all sailors and
depended on folk like you and me to listen out when they were playing with
their boats.
Moving inland to Blandford not far from the signals depot i was introduced
to very covert operation but again, my copper wire could be strung out but
only 1in from ground. This was a super challenge. Would it work? No said
many, you will need height. But i remembered an article by a G3 station
where he fed his aerial into ground finally via a very high powered
resistor. So i did the same and my log will show work all over the EU and
the world on all bands CW with no probs at QRP. Mind you my SEM ATU was
part and parcel of my good fortune.
But returning home from the FARELF proved to be quite a learning curve and
it was mainly all Coax aerials (Low noise) there is a special formula
which, if you are interested i will be happy to share with you. These were
in the main Attic sited again for covert operation and they worked very
well so i stayed with QRP from 1988 until the present day. I have worked
ZL and 9v1 many times with less than 1 watt.
But now having been persuaded to look at coax traps i see the beauty of
the beast they are easy to make and are waterproof and most of all they
work, just get your formula book out. The last two ive made is the 11t
over 4.5 former for 40mtrs and my very own design of the manky ur43 28t
over a 4.5in former for Top Band.
Imagine your coax========= inner core----------- Just a bit of time and
patience is needed ========)))))))))))========(40mtrs) and then the Top
band ====)))))))))))))))))))))))))))======= Remember to wind close then
drill hole in former at both ends and solder inner to outer so at one end
you have the inner core cannected and at the other end the outer
connected, check with your meter for closed circuit and the job is almost
done. The connections inner to outer are best inside the former. Now all
you need is a bin liner to cover and protect and you are almost done. Seal
with insulating tape and then choose (your the Ham) the best location to
site the trap. Allow at least 10 days to settle down then you can quite
safely go to full power on key down for a few seconds reducing to the
power you decide to use.
Working the Maldives one day, my best-man Ted G6FB (SK) happened around
and was delighted that all was going so well so we got stuck into his
bottle of Ouzo which is another story-yuk. Please do not hestitate to
write if you need any help. More later.
Best wishes/Meilleurs sentiments/Bo-jong/51/73,
Rodge.(G6XCJ also G0CJM) -at-gb7imk.ampr.org
SMS ONLY:g0cjm-at-winlink.org
07/02/2008 Registered WinPack-Telnet V6.80
In memory of Roger Barker G4IDE(SK)(Programmer)
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