On Sat, 25 Sep 2010 14:57:41 +0000 (UTC), Thomas Karpiniec
wrote:

Hi Stuart,

"Stuart Longland (VK4MSL)" wrote:
The catch is, I'm not sure how to go about impedance matching, with
the loop having a theoretical impedance (so I hear) of 100ohms, the
ribbon being 300ohms, and a radio that expects 50ohms. I'm not sure
how the feedline characteristic impedance will impact on things, being
300ohm... there's no such thing as 50ohm ribbon in the shops AFAIK.
I'm not sure this has to match though. The antenna itself though,
does need some sort of transformation back to 50ohms.

One trick I saw on a ham's web site (I can't find the URL sorry) was to
make home-made ribbon cable, running conductors through regular spacers.
That could be a good option for you simply because you can make it super
light-weight, but it also gives you flexibility with the spacing and
therefore the impedance.

I'm not qualified to say how loop antennas are normally matched, but I
thought that particular idea might be helpful in your case.


Chapter 17 of the 1962 ARRL Handbook describes how to homebrew
balanced tuners for VHF. I use the 6M version with either a 6M Sterba
curtain or a fullwave 160M loop, works FB. I also built a 2M version
that works well but doesn't get much use as I don't use that band very
much.

73 de n4jvp
Fritz


Long time no chat! Cheers,

Tom VK7NML