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[email protected] · January 19th 07, 07:58 AM posted to rec.radio.shortwave

wrote:
I must be doing something wrong.

Frequency 6.486MHz (BTW arabic male)

I first tried 2 active dipoles seperated by 100' on a north to south
line.
Next I tried a 50' wire 6' off the ground with a WinRadio WR-LWA-0130
"long
wire adpator, with either of the active dipoles, then I ran another 50'
at right
angles for the first, also with a WR-LWA-0130 and tried them all with
my
Mini Circuits ZFSC-2-1, that while rated for 5~1000MHz operation has
been
tested and it works fine down to well below 100KHz.

The nulls we less frequent but much deeper when they came.

I then used a 2nd R2000 and fed each receiver with different antennas
and just let
the audio "mix" from the respective speaker outputs. The active dipoles
gave the
best overall effect. There was a very pronounced comb filter effect
kind of like
The Small Faces "Itchycoo Park" from 1967, or Gobi Grant's "The
Westward Wind".

Not too bad I think I will investigate some more this weekend.

At this point a couple of active dipoles into a broadband "phaser"
allow me
to peak the signal and that works better the diveristy. Now what would
happen if I had 2 sets of active dipoles feeding seperate phasers
feeding
seperate receivers?

I can get at the AGC in my R2000 fairly easily and it should be fairly
simple
to build a comparator to pass the strongest signal to the audio chain.

Just what I need another radio project.

Terry

Hi,

I would recommend reading the diversity section of "Communications
Receivers: DPS, Software Radios, and Design, 3rd Edition" by Ulrich
Rohde, Jerry Whitaker.

Generally speaking, mixing the inputs is helpful but not as good as
actively switching in the stronger signal.

This is somewhat more complex unless you have two receivers.