I had a few things to share about the ANC-4 I have been using.
You might remember that I am using it to phase my transmit
antenna (80 foot tower) and a second tower (95 feet) located
105 feet to the South-West of it. Both towers are gamma matched.
This phasing is only applicable to the receive mode.
First off - some words about JPS Communications. I blew up my
ANC-4 in this application - because the coupling is too tight
between the towers. They have a "lifetime" warranty and fixed
it for free and send it back. I even tried to pay them some
money to cover their shipping, but they returned my check.
To overcome the overload problem, I am using a box I made for
beverages which plugs into the PTT line going to the amplifier.
It disconnects the "noise" antenna when I am transmitting.
It might be easy to modify the unit to do this by adding another
relay. It might also be neat for it to trigger off the PTT
line as well, so it is switched out before the amplifer can
be activated.
The performance of this system is pretty amazing. I was able to
take K7K from S9 to almost nothing by nulling them out. I believe
the system gives me a couple db improvement in signal to noise
ratio in the desired direction.
I also understand the newer units have a built in AM BC band filter
that can be enabled (in two steps). My unit doesn't have this,
but JPS supplied an external filter.
73 Tree N6TR
tree@contesting.com
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