Reg,
Sorry to butt in but I have a loop question.

Presently I have a loop for 20M made from 1/2 inch copper pipe in the
attic. I use a large 4500v variable capacitor turned by a small motor.
It works very well and is better than my GAP Challenger vertical (31ft)
in favored directions. Noise is higher in the attic but I can bring that
down with a Timewave ANC-4 noise canceling (by phasing) unit.

My question is about the coupling loop. Everything I had ever seen on
the coupling loop was that it had to be an odd construction of coax,
i.e. some sort of Faraday shield?? I noticed your comment to Adrian
about a simple stiff wire coupling loop.

Is this loop simply shield to one side and center conductor to the other?

Is there a size/diameter ratio of the coupling loop to the main loop?

Is the antenna now more likely to have increased noise due to an
"unshielded" coupling loop?

Thanks & regards,
Dick N3HKN

===================================
Hi Adrian,

Pleased to hear you are now working OK

The correct way to reduce SWR is to adjust the diameter of the
coupling loop.
There's no way to tell which way to adjust the loop except to try it.
It may not be the best setting for ALL bands.
But it IS better to do without the tuner if you can manage it.
Adjust the loop diameter for minimum SWR on your favourite band and it
will also be fairly close on the other bands.

It will be easier to change the diameter of the coupling loop now that
it is just a simple length of wire.

Now that you can hear some noise, the correct way to set the loop and
receiver both to the same frequency is to VERY SLOWLY, vary the loop
tuning capacitor for maximum noise in the receiver.
----
73, Reg, G4FGQ


From - Wed