Posted by
wc1m on
Jan 09, 2012; 6:34pm
URL: http://elecraft.85.s1.nabble.com/diversity-receive-antennas-tp7165975p7169020.html
I use diversity primarily on 40m in contests. I have the transmit antenna, a
2-el beam at 110', in my left ear and a 4-square on the AUX port in my right
ear. The antennas are separated by about 320 feet.
I couldn't testify as to whether there's any diversity gain, but there's no
question that the setup is extremely effective when there's QSB on the band.
It's also quite helpful when there's noise, like static crashes, that might
be picked up more by one of the antennas than the other. A surprising thing
I've learned is that sometimes signals are louder on the 4-square that I
would have expected. Normally, when I switch back and forth in
non-diversity, the beam is almost always considerably louder. But when
listening in diversity, the 4-square is sometimes as loud as, or louder
than, the beam. That's the magic of arrival angles and one reason why stacks
are great to have!
Both of the antennas have 20-25 dB F/B, so another bonus to this
configuration is that if I hear a station calling from the direction
opposite to where I'm working, I can quickly switching the 4-square to that
direction -- even while transmitting.
But Guy really hit the nail on the head. The most remarkable effect is how
the spatial positioning of signals makes copy much easier, especially in
large pileups where many stations may be close in frequency. The different
signal arrival angles, and the resulting different position in the audio
sound stage, become the distinguishing factor when loudness and pitch are
the same. It doesn't bother me that I might be hearing the station primarily
in one ear because I'm used to operating SO2R.
Of course, I can't use diversity when I'm tuning the second radio, but I use
it primarily for working large pileups when the rate is so high I can't tune
the second radio anyway. When the rate drops, I leave diversity on and
switch to listening to both radios. The run radio is in my left ear and I
hear the beam. So it's no different than when I do SO2R with diversity off.
If a station calls me on the run radio, I just switch back to both ears on
the run radio and I'm in diversity.
I've sometimes used diversity on 80 and 160, using a wire transmit antenna
and a beverage. It's helpful, but nowhere near as effective as it is on 40m.
73, Dick WC1M
-----Original Message-----
From: Barry N1EU [mailto:
[hidden email]]
Sent: Monday, January 09, 2012 7:46 AM
To:
[hidden email]
Subject: Re: [Elecraft] diversity receive antennas
goldtr8 wrote
>
> What do folks use for diversity receive antennas.
>
ANY two antennas delivering reasonable signal strength on the rx band can be
quite useful for stereo diversity reception.
I've been using diversity since 2003, on the Orion and the K3 (see
http://n1eu.com/K3/diversity.htm )
Even two dipoles at different heights in the same direction can be quite
useful - you've got arrival angle diversity. So just experiment - antennas
need not be elaborate or widely spaced.
I often use tx antenna plus Beverage on all bands (yes Beverage is often
helpful on 15M and occasionally on 10M) and normally use two Beverages on
160M/80M.
Besides any advantage in improving signal readability, the stereo effect
that diversity provides is a very enjoyable listening experience.
Barry N1EU
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