Jonathan,
I don't really know why the T1 would be off topic here, but ...
The answer to your question has two parts:
1) in theory, a half wave wire is an antenna complete in itself and does
not need anything else - and that is true whether it is fed at the end
or at the center or anywhere in between.
2) in practice, the tuner circuit should have some reference to tune
against, and if you do not provide that reference it will use something
(the ground in the T1, the coax shield, your body, etc). It is usually
better to control what that 'something' is by using a counterpoise wire
- just let it lay on the ground.
2a) the T1 tuner is of the L network type which may not work well into
very high impedances. An end fed half wave presents a feed impedance of
about 4000 ohms. A parallel tuned circuit with the unbalanced input
created by either a link or a tap on the coil works best with these high
impedances.
Overall result:
You may be better off using something different than the half wave. Try
the W3EDP lengths for starters, an 85 foot radiator wire and a 17 foot
counterpoise if the antenna is for 80 meters and up, or half those
lengths for 40 and up.
73,
Don W3FPR
Jonathan wrote:
The other thing OT: I have the T1. When operating in the field, as I do with
the ATS3B--say I'm running a half-wave inverted L antenna with one radial. In
that case I use a BNC to two-pole adapter running the radial off the black
side, and the main element off the red side. Would I benefit from some sort of
ground attached to the ground post? Even a large metallic object? Or would this
not have any effect?
Just wondering the general concept here.
Jonathan KC7FYS
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