>From "mike l dormann":
"my antenna options seem to me to be a wire slanting from the window
down to the parking lot below ... with an antenna tuner and the
building neutral as a counterpoise."
The antenna you propose may actually have 2000 ohms end feed Z and
more. Many tuners only add a 4:1 boost to a limited range of the tuner
proper, and are anything but efficient in that mode.
Particularly with the low voltages at your power levels, you might
want to consider a parallel LC network with one end of the coil to the
wire and the other to "ground". Connect coax shield to "ground" and
center conductor to a tap on the coil. Vary tap, coil size and
capacitor for match.
My own experience with a "neutral" as ground in an apartment building
was that it was very noisy, and it helped a lot to disconnect the
connection to neutral during receive. The coax to the rig was enough
of a counterpoise on receive. My sloping 80m halfwave worked well and
Q's included Europe, Africa, South America and Antarctica with 25
watts output from an 807.
I have had good luck with end-fed halfwaves using both tapped and link
coupled parallel LC matches.
Good luck and 73, Guy.
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