Re: Portable antenna(s) #antennas #v6


Gordon Gibby
 


Our group built well over a dozen Endfed 49 to 1 baluns for resonant half wave antennas (against ground.  ) FT – 140 Dash 43 from kits&parts.com in Florida   Because it’s a high impedance system, even a 1 foot stake in the ground works pretty well. 

After we did the project, I got to working with the  spectrum analyzer and discovered we could reduce the losses even more by going to 4 turns/28 turns total. (improved design) That gets the losses considerably lower.   For higher power operation, consider one or two FT– 240 Dash 43 toroids ,3 turns/21 turns.   These will not have the capacitive adjustment that the commercial units have, but they will work quite well.  I’ve gotten a look inside some commercial units and they are designed very similarly. 



Gordon Kx4z 



On Feb 17, 2020, at 17:33, Curt via Groups.Io <wb8yyy@...> wrote:

Mark
Also check the 3 band vertical matching unit at qrpguys. I got a squid pole from Asia in a few weeks, or try cabellas.

Jack

I confess to owning 80m qro efhw from myantennas. But for qrp easy to make one, web has the info, main part is a ft120-43 or an order to qrpguys. The trick for all band is that loading coil near the feed.

We know an efficient antenna avoids discouragement with a few watts.

73 curt

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