[Elecraft] Re: KX1 antenna ideas for 80-40-30-20? (we'll post yours on our KX1 page)

[wayne burdick]

For 80 m, we recommend a resonant antenna if your goal is to maximize 
results using QRP on this band. Other ideas:

1. A loading coil can be used with a shorter antenna, but be sure to 
adjust the coil to resonance, first, with the KX1's internal ATU 
bypassed. (During initial experiments to determine coil size, an 
external analog SWR bridge is recommend, since that's the fastest way 
to find the SWR dip.) The internal tuner may help extend the tuning 
range on 80 m after this pre-tuning step has been taken.

2. If you want to stick with the typical wire-in-a-tree antenna often 
used with the KX1, and don't want to use a loading coil on 80 m, you'll 
need a lot more wire than before -- something like 60-70 feet. Again, 
the KXAT1 may help tweak the antenna for best SWR so that fine pruning 
isn't needed. But note that this wire length is close to a half-wave on 
40 m, and a full wave on 20 m, which may compromise SWR on these bands. 
So the best solution may be to toss *two* wires into the tree: one that 
presents a relatively good match on 40-20 m, and another that's much 
longer that can be loaded on 80 m. Both wires can be connected to the 
KX1's antenna jack at the same time. Determining the best lengths to 
use is left to the reader as an exercise :)

Any all-band KX1 antenna designs posted to the reflector will be added 
to our KX1 web page, with credit to the experimenter. Let the fun 
begin!

73,
Wayne
N6KR


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