Topband: shortened & low dipole for 160M--transmit/receive issues

[Frank Norton KB8XU]

Hello to all,

I am one of the folks who lives on a city lot, but lucky enough to have it 
be fairly large (120' x 150'),  The house is located in the front and side 
(L shaped ranch).  A single 50 foot crank-up tower on the northern 
edge/front corner of the lot is the only "high" point (about 0.1 wavelength 
above ground).  I have been studying Low Band DX'ing, as well as the 
Antenna Book from the ARRL and decided that my best hope for a decent Tx/Rx 
antenna for 160 M and secondarily for 80 M is a slightly shortened dipole.

Luckily--I was able to purchase a Spi-Ro D-162 dipole for at quite a 
bargain from a local ham, he realized how long 208 feet is on a 50 x 100 
foot lot.  The dipole is very well built except the traps for 80M are rated 
at only 600 watts (at what SWR?). My  questions are numerous but primarily 
related to optimizing the functionality of the antenna on 160 M, and 
secondarily keeping the inherent 80 M function in good shape as well.

By "optimizing", I am concerned with ability for use on both receive and 
transmit.  To divide the question further, first of all what type of 
loading would be best to maintain the 208 foot (0.4 wavelength on 160 M) 
length of the antenna but raise the power handling ability 
significantly?  600 watts is just not going to cut the mustard at 0.1 
lambda above ground level is it?

In order to improve the power handling ability of the traps---weight and 
size seem the limiting factors here, agree?  A coaxial wound trap/coil 
would probably weigh 8-10 lbs each using RG 211. Teflon might work, yes? 
Other L-C combos come to mind?  Any suggestions welcome, but I would like 
to maintain the inherent Q of the antenna.  (I cannot use an all band, 
harmonic resonator---too many hostile neighbors,  One peep from a cheap 
stereo or clock radio and the phone is ringing.)

The other significant question is on receive.  The dipole will fit almost 
as a flat top at 40-45 feet, but I have to bend it in the horizontal plane 
to run along the West and North sides of the lot. I will also have to droop 
one end at least 16 feet to stay on the property.  My major concern on 
receive is that the North leg of the dipole will be parallel to a high 
voltage power line (about 50 feet away).  Would it be better for noise 
purposes, to slant that leg towards ground (in the manner of an inverted 
V), or would this be of benefit-->worth the sacrifice in "height" above 
ground on transmit?

My final question is what have those of u in my situation used for end 
supports (no my wife won't go for the 2 extra towers, u can bet I already 
considered that subject)?   Anyone ever had any experience with fiberglass 
twist lock masts, similar to those sold by Radio Shack?  They expand to a 
total length of about 30 feet I believe.  Any ideas appreciated.


Tnx es 73 de Frank KB8XU