Topband: Where to place a preamp? Switching Beverages?

[Pete Smith N4ZR]

Having totally struck out raising this topic on Towertalk, I'm bringing 
it here in the hopes of getting some solid advice.

I have a 20 dB ARR preamp of the type praised by ON4UN in his book.  I 
want to use it with a variety of RX antennas - loops, BOGs, etc. - that 
have very low output levels.  My choice is whether to put it at the 
antenna end, incurring the added complexity of sending 12V DC to it via 
the coax, or to put it in the shack.

I realize that if this was 2 GHz, there'd be no question where it should 
go.  But for 160-meter purposes, I don't know.  I am wondering if 
putting it at the antenna end might enhance directivity, by amplifying 
the signals from the directive antenna relative to any pickup on the 
350-foot feedline.  I will be trying to choke as much common mode 
current as possible, at both ends, but am not sure how effective I can be.

On another topic, I am building a hub for BOGs.  Rather than switch at 
75 ohms and putting a matching transformer on each BOG, I wonder if it 
would be feasible/desirable to switch at the high-impedance side and use 
a single transformer.  It would certainly simplify the hub.

Any advice would be much appreciated.

-- 
73, Pete N4ZR
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