[Elecraft] Matching End-fed Halfwave with K2/KAT2?

[Daniel Reynolds]

I'm considering using an end-fed halfwave for Field Day, and I have an idea how
I might implement it, but need some technical assistance from those in the
"know".

What I'd like to do is pick up a few toroid cores (one to break, one to lose,
and another to use) to build a simple transformer with a couple turns attached
to a short (2-3 ft) pigtail of coax going back to the K2/KAT2. I'm hoping I can
experimentally determine how many secondary turns to use for the halfwave side
of things. Will the KAT2 be sufficient to handle the 'fine tuning' after I
handle the major impedance transformation through the toroid? or will I need to
get my hands on an air variable to do fine tuning on the antenna end of the
pigtail?

Any ideas on how to best implement this would be greatly appreciated -
especially since I'll need to know which core(s) to buy this week so I can test
this out before Field Day.


If there's a cheaper way to do this using simple plastic pill bottles and air
wound cores - I can do that too ... but I also like to wind toroids ;-)

I'll probably end up with 1 or 2 antennas ... a 40/20/15 (40m halfwave), and
maybe an 80/40/20 (80m halfwave). I may try to orient these crosswise to
provide E-W coverage on 80/40/20 and N-S coverage on 40/20/15 - knowing that
both of these antennas will start producing interesting lobes on the shorter
wavelengths.

Thanks for any help this list generates...

73,
Daniel AA0NI
Oklahoma City
http://www.aa0ni.org