Topband: Isolating a TX antenna

[Mike(W5UC) & Kathy(K5MWH)]

Greetings All:

I just finished building a vertical RX array for 160 meters using 
K7TJR's Hi-Z pre-amps.  However, it looks like I am getting some 
re-radiation from my Inverted L.  The nearest vertical in the array is 
about 35 feet from the Inverted L.  Yes, I know that's quite close, but 
real estate dictates where these antennas go.  As my good friend, K5SCR 
says;  "you gotta dance with the one that brung you".

I grounded the Inverted L at the base, and saw no reduction in noise.   
However, when I let the Inverted L float, that is open at the base, I 
see about a 2 S Unit drop in received noise in my FT-1000MP.  In a 
properly calibrated FT-1000MP, 2 S Units should represent 6 dB.  The 
question is:  How much noise should I expect, is 2 S Units reasonable, 
and what other methods should I consider to reduce, and hopefully 
eliminate this problem?  I'm ready for winter.

Thanks & 73,
Mike, W5UC