[Elecraft] diversity receive what bands

[Fred Smith]

Bill

A very nice antenna farm you have for sure! If I might ask how long is your
feed line from the beverage and the 4sq's to your shack? And the TX 160m
distance and feed line used helix I'm guessing?


73,
Fred/N0AZZ
Monett, MO.




-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Bill W4ZV
Sent: Monday, November 11, 2013 5:28 AM
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] diversity receive what bands

Jim Brown-10 wrote
> Beverages tend to favor higher wave angles, while verticals favor low 
> angles.  Those who have lots of land like to install both Beverages 
> and vertical RX arrays (Hi-Z Antennas, DX Engineering are US companies 
> that sell them). I've seen reports of signals appearing an hour 
> earlier on one antenna than the other, then disappearing from the first
antenna.

Beverages and vertical arrays actually have very similar takeoff angles
(e.g. 25-40 degrees).  Salt water dramatically lowers the lowest takeoff for
verticals and a poor ground will raise it.  Lengthening Beverages will also
lower the takeoff angle.  See Graph 3 below for an example of the latter on
160:

http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/Bever
age.htm

At 1 wavelength (~540' which is about the minimum useful Beverage length)
the takeoff angle is 42 degrees.  Lengthening it to 2 wavelengths lowers the
angle to 27 degrees.  

Below are two plots (top and very bottom) of my antennas which demonstrate
the difference between a low dipole (90 degree takeoff), a vertical array
(22 degree takeoff) and a 2 wavelength Beverage (24 degree takeoff):

http://users.vnet.net/btippett/new_page_10.htm

I normally use Beverages on one port and an RX4SQ on the other port.  I can
also switch between the RX4SQ and my TX array (Spitfire variant).  On 80 and
160 I use diversity almost 100% of the time.

73,  Bill  W4ZV





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