Ted wrote in news:43bd1032$0$82676
:




I have about 40 feet of garden to erect an antenna....Could anyone tell
me if I took 2 20 feet length of twin ladder and shorted the ends
fed one side of the dipole with twin ladder and connected a 52 ohm
resistor across the other side so the tx would see a match would be
better than feeding a 40 foot endfed through an atu...
My thinking is that most of the small antenna on the market are just
dummy loads with a small amount of wire attached and appear to work so
would my 40 feet work better.. ??

If you're looking for transmit efficiency, then a resistor is not going
to help you except to keep the standing waves down. You don't, in
practice want such a resistor to be dissipating more than about half your
power. Even that much is a three decibel loss (about half an S unit).

If it was my space, I'd start as high as I could get at one end and run a
sloping dipole with 300-ohm or 450-ohm feeder to the atu. Make sure your
atu has a 4:1 balun in it or get a balun that can give you at least this
ratio. And just feed the nice sloper on as many bands as you can tune
it! It won't be earth-shaking on 80m and will probably wimp out on 160,
but I bet it would be tolerably good on 40 and really decent on 30 and
up.

Dress the feedline away from the main wire at right angles and twist it a
bit. Make sure to follow proper line-dressing procedures where you bring
it into the house (or use a 4-1 balun and run coax the last bit). And
fiddle with the length of the lower arm of the dipole until you get no
common-mode antenna currents on the feeder, say on 30m. That should do
it.


--
Dave Oldridge+
ICQ 1800667