The other day I posted an antenna question about making a K1 antenna
that avoids halfwave multiples (& thanks again to the guys who replied
offlist). From the calculations in that note and some modeling by
another op it seems the ~18m/60' is probably the length to try there.
But end-fed halfw
Hi Mike,
Another option is to wind a transformer on a toroid with a 3:1 turns
ratio which will give you a 9:1 impedance transformation. If your
antenna has a high impedance,
which an end fed half wave will naturally have, the transformer will
drop the impedance down into the range of your auto
Has anyone tried either method? (That is,
direct connection of halfwave end-fed or tapping an inductor.)
Hi Mike,
This topic comes around every few months, so you can find a lot of
knowledge - both theoretical and practical - by searching the TenTec
and QRP-L archives for 'End Fed Halfwave' or
You are right about the improved efficiency of the end fed dipole (i.e. half
wave) antenna. From the standpoint of radiation, it's identical in all
respects to a center fed dipole. The only difference is that you're feeding
at a voltage loop instead of at a current loop. For portable use, that mean
FWI to the Group:
Another form of the "end fed dipole" that I have been using was written up in
August 1991 QST and has also been shown in some additions of the ARRL Handbook.
It is a real dipole - 50 ohm input impedence. The first "side" is made as per
standard formulas. The otherside is made u
Wow. Thanks to all for the wealth of information regarding this type of
antenna. Plenty to consider! Deciding what and where to tradeoff for a
given use is what makes each set up unique.
I think I'd like a dipole/doublet for use when supports are available
and an end-fed of some sort when I
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