[Antennas] 40m mobile antenna e.r.p. compared

[PaulKB8N at aol.com]

Sam,
 
Don't limit yourself to a vertical antenna.  You can buy a 12' fishing  rod 
(black), discard the top whip section, run two parallel wires either inside  or 
outside of the pole, and use #24 wire to form a balanced dipole that would  
attach to the diagonal corners of the roof.  The wire will be so fine that  it 
won't even be noticed, and you can get about 33' on either side if you run it  
diagonally across the roof.  Don't use end insulators, use fine fishing  line 
to support the 33' ends.  Feed at the base with 300 ohm  twinlead and you'll 
have a very effective antenna that you can tune on 40, and  all the bands 
above that, including the WARC bands,
 
This full-sized antenna will outperform any mobile whip you can buy.   It may 
even work marginally on 80M.  With the wires above the flat roof,  you have 
less likelihood of inducing RF currents into the ceiling wiring, which  may 
happen with radials.
 
I used this technique on a flat-roofed apartment in Okinawa, Japan, and  
consistently worked the states on 40M running QRP.  Trust me, your limiting  both 
bandwidth and performance if you use a mobile antenna of any kind.
 
Paul, K5AF