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Re: Topband: Inverted L improvement question

To: topband@contesting.com
Subject: Re: Topband: Inverted L improvement question
From: Wes Stewart <wes_n7ws@triconet.org>
Date: Sat, 22 Dec 2018 07:04:49 -0700
List-post: <mailto:topband@contesting.com>
Although licensed for 60 years I'm a relative newby on topband.  (I did work VE7 in 1959 but that's another story).  I decided to semi-seriously take up the band to acquire my 9th DXCC band award.

As I've described before, pardon the redundancy, I worked my first 70 entities using an inverted-vee dipole with the apex at about 45 feet and the ends down around six feet.  Of course conventional wisdom says that this couldn't possibly work for anything but local contacts.  A year ago, I replaced the dipole with an inverted-L, 55 feet vertical, the rest horizontal, over a skimpy radial field of about (so far) 20 insulated radials each 55 feet long laying on the desert dirt.  I both transmit and receive on this antenna, as I did the dipole before it.  I've since worked 40+ stations, completing DXCC plus a few.

Perhaps I'm blessed with a relatively quiet location, although unlike some I'm not miles from civilization, but not in a subdivision either.  I have made zero effort to silence noise sources in my house, but do work with the local co-op power utility to silence obvious noise sources. (Their sleuth is a ham)   Although I'm considering an RX-only antenna, and it might be eyeopening, I'm not yet convinced of that.  Anything I would use on RX would probably have a broad peak and get its noise rejection from the rear.

Examining where most of the unworked DX is from here (EU, ME and central AS) the paths are mostly over the (noisy) continental land mass of NA (and the polar region) at my SS or early evening.  The null of any RX antenna pointing at these areas would be looking at the sunlit Pacific Ocean.  At my SR, the converse would be true.

So all things considered, using only 500W (10dB too few according to one of my friends), I already hear as well as I'm heard.  My bigger obstacle is QRM from the east. Nevertheless, I'm willing to try an RX antenna, if I can be convinced it will be of benefit, so I'm open to suggestions.

Wes   N7WS




On 12/19/2018 7:13 AM, Rob Atkinson wrote:
If your inverted L is any good at all it will suck as a receiving
antenna.  This is one of the key things to accept about medium wave
but many casual 160 m. operators can't wrap their heads around it.   A
flame throwing tx antenna will probably have a completely unacceptable
noise level on receive.  Tx/rx reciprocity works on HF but not as well
on medum wave.   Separate rx antenna(s) are mandatory.    A
significant irritant on 160 are the operators with poor antennas that
hear great, therefore they expect to be heard equally well, and can't
be made to believe they are piss weak when they transmit.

Rob
K5UJ
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