On Saturday, September 13, 2014 1:00:11 PM UTC-5, Lostgallifreyan wrote:


Those files are very convincing. As well as the orientation there seems to

be a vast improvement based on capturing energy at a small region in space, a

long wire seems to mush out the signal maybe partly due to occupying so much

space. Maybe I misundrstand, but it does seem like the spatial resolution of

a loop's small occupancy has a direct relation to the resolution of the

demodulated signal.

The 50m wire is not going to be too directive on such low frequencies.
It's not acting as a long wire or beverage. It's way too short.
It's just a random wire and will be fairly non directional on LW and MW.
So you pretty much hear everything on freq, and it can sound like mush
if multiple stations are being heard.




I think someone posted some design notes or links during one of my first

threads a month or so ago. I'll look at your loop in detail (I like the

narrow but stuff gauge of UPVC pipe (I'll maybe chose a black 20mm conduit

because that's easy and cheap to get here, and I've used it for other stuff

too), and hopefully I'll figure out a good waterproof capacitor for loop

tuning too.

Being as the caps used are generally old broadcast variables and such,
you could just have a plastic cover over it. But I use all mine indoors
where I can turn them, and don't worry about that. I'm not going to sit
out in the rain to listen to a radio. :/

The type PVC doesn't matter much as long as it's rigid enough to keep
from bending with the wire tension.
I've built them from the usual white PVC which I think is 3/4 inch OD,
and I've got a big one that uses a thick 2-3 inch?? or so piece as a mast,
and 3/4 inch PVC run though drilled holes on the thick PVC mast. So pretty
much only two pieces not counting the T's. The 16 inch loop you heard
on the recording is about 12 or so turns wound on a plastic blower housing
with a mount on the back.

It's a round loop, and sits on the floor in one of my stands. It can
tune the whole MW band. The big loop I have which is a 44x44 inch diamond,
uses a cap out of an old stereo. It has multiple gangs which I can switch
in and out. I think it tunes from around 500 to 2000 kc or so.. And lower
if I tack on extra fixed caps.




One question: Is this going to be good using the 100 or so turns I put on the

end of the PL-390 ferrite rod? Hopefully this is the ideal way to couple the

signal into the radio, because it will make life very easy if it is.

I have no idea what you mean by the PL-390 ferrite rod.. Sounds like a
small antenna on it's own with 100 turns of wire.. ??

I feed the small loops with either a single turn coupling loop to coax,
or if you use a portable you can just use the ferrite bar antenna in the
radio, and close couple it to the loop by holding them close together and
finding the sweet spot where you get max signal.
Of course if you did that, you would want to rig a mount to hold the radio
in place.

I fed all mine with coax, usually to my IC-706mk2g. I remember one time
I tried the 16 inch loop on a AC Delco car radio that was in my truck.
It was hot as a firecracker using that loop for an antenna. Much better
than the truck whip.

Some will speculate that the balance could suffer from using coax directly
to a single turn coupling loop with no balun, etc.. But it's never been
a problem for me. You can tell by the deep nulls I get, that balance
is not an issue. I can make daytime ground wave signals totally vanish
if I null them out, and the nulls are inline with the loop and not
skewed. So no problemo using that feed method here.. :|