The answers you get on this group are likely to be far less than useful. I
would recommend rec.radio.shortwave.

"clvrmnky" wrote in message
...
I've got a little shortwave receiver that has a decent amount of gain in
it's antenna input. I've been experimenting with different lengths and
placements of the wire, and seen some interesting homebrew antennas I
might try once the snow melts.

I know that receivers are less demanding of impedance matching in
general, but my readings suggest that I should have a balun (unun) of
some sort to match the impedance better, since I'm pretty much stuck
with end-fed longwires. This should get more signal to my front-end,
and a proper shielded connection to my receiver should help minimize
stray RF noise.

I'm a renter, so I'm going to experiment with running a wire along the
eaves on the balcony, which is open to two sides of the house (wooden
two-story.) That is, I do not have the luxury of using the yard, trees
or anything.

So, my idea is to have a long wire (or folded longwire made from a
length of twin-lead) go to a balun (or unun, since this is really
unbalanced-to-unbalanced) and then run a downwire from there to my
receiver through a window.

I'm guessing the real advantage would be realized if I had a good RF
ground at the receiver and/or balun. This will be sort of tricky. I
don't even think I have copper cold-water pipes anywhere, and running
copper braid over the balcony, down the side of the building and into
6-foot rod just ain't going to happen. I've heard of people using
houseplants for poor grounds when no other was available, and I have
many kilos of wet earth on the balcony.

I've seen a neat artificial ground/antenna tuner from MFJ (I think)
which seems to offer a lot of bang for the buck. It even has multiple
inputs for high-Z single wires. Would this be useful for SW?

Finally, I'm probably just going to wind my own balun out of a ferrite
core. I just can't seem to find the details on how to wind the copper.
Do I wind the primary first around the whole core, and then the
secondary on top of it? Sorry if this is stupid question, but I've got
most of the math figured out (i.e., no. of turns and such) but since
I've never seen a balun... my assumption (right or wrong) is that it is
just a special transformer.

Thanks for your comments.

-- cm