with attic loop
Lacking outdoor space for that antenna?
Here's what one can do:
Put as much wire in your attic as you can run in the shape of
a loop. Establish the feedpoint as high as possible. Use heavy
gauge wire to minimize losses. I am soon to replace my smaller
gauge wire with #8 speaker wire.
Try to stand the antenna wire off from the rafters at least by
a few inches. I used the longer of the two stand-offs that RS
sells. I have been feeding with twinlead but will soon replace
that with window line. Use an efficient tuner.
Nothing unusual or tricky about it.
Just the elementary stuff.
I have about 95' of wire in the loop. It tunes easily on
all frequencies above 7 MHz. I have been able to work into Central
Europe and Africa on 40 meters with 3 watts. Of course, that only
happens when propagation is kind.
The loop will never perform nearly as well as an outdoor antenna,
high and clear of surrounding objects. It does allow my to get
on the air from a location where outdoor antennas are impractical.
As is typical of loops, there are some deep nulls. To add
some variety and improve coverage in general with the loop, my
next step will be to insert a lamp switch at the point opposite
the feedpoint. A long run of lamp cord coming through the same
hole in the ceiling as the feedline and running down to the operating
position will allow me to switch from an open to a closed loop
with a gentle tug. The open loop might not be as efficient but
will have a different pattern of radiation which might allow me
to more effectively communicate with some areas that are in the
nulls of the closed loop.
If you can get a bit more wire up in your attic than I am able
to hang, the open loop might perform as a folded dipole on 80
meters or lower.
Don't be discouraged if you are unable to put up a good
outdoor antenna where you operate.
I have always wondered what attics were good for.
Now I know.
One word of caution.
Spouses, it appears, do not take kindly to having large
holes put into the ceilings of their homes with keyhole saws.
Be sure you were very good to your lovey on Valentines Day before
proceeding to do that. Maybe you can get around it by running
out the window and back under the eaves.
posted on the Low Power Amateur Radio Discussion mailing list, February