In a message dated 96-09-11 12:15:32 EDT, you write:
>Im interested in this myself I follow you up to the point where
>you say "Bridgeing amplifiers driving the receivers allow selection of
>both ends wiout affecting termination" So the beverages only have
>transormers at ends and the resistive load is at the shack??
There is so much ambient noise on 160 that both ends of the antenna can be
returned to the shack (when properly matched) and terminated with a high
input impedance amp bridged across the actual termination resistor.
The requirement is the Beverage must have a reflection transformer, a 1:1
transformer with a CT on the Beverage end and the secondary connected from
the CT to ground, at the far end (grounding one leg, as suggested in some
texts, does not work well) and a step down transformer with a center tap at
the Beverage end (the high impedance primary). The low impedance secondary of
that transformer becomes the far end connection point to a coaxial cable.
The center tap of the above transformer goes to another stepdown transformer
that becomes the near end connection point. It goes to a separate coaxial
feedline.
These lines both come into the house where you can phase shift the ends, play
with termination, or whatever you like. I used to recombine mine through a
phase shift network driven by bridging amps, to steer nulls around.
>Doesnt the resistive load need to be at the far end of the Beverage to
>work?
Nope, it gets it's resistive load via the path through the transformers and
feedlines. Same electrical thing as terminating outside except now you can
adjust termination, receive both directions at once on separate receivers,
combine the signal through a phase and amplitude control, or whatever you
like. It just increases the flexiblity of the system.
73 Tom
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