Topband: Automatic Switching on 80/160 Vertical

[Tom Rauch]

> replaced by the linear loading wires.  I would like to
avoid coil
> loading with its inherent losses.

Linear loading simply inserts a compensating inductive
reactance that cancels the antenna's capacitive reactance.
If the antenna is X feet tall and needs Z reactance, you can
get it through ten feet of wire in a coil with a Q well in
the hundreds or a linear loading stub using four times the
wire length with a Q in the dozens (or less).

Linear loading really just replaces a coil with a system
with even more loss, assuming you use the same size wire in
each. This would especially be true if you added a capacitor
across the open end of the linear loading, which further
reduces the already poor Q.

Also, the last thing you want to do is fold the linear
loading stub downwards. Folding the linear loading stub
downwards means you lower the effective location where the
loading is inserted, and that's not a good thing.

You could use a complex trap like Butternut uses (which
would have higher efficiency with a coil, rather than a
distributed inductor like a linear loading stub), but I'd be
more inclined to just use a regular trap at the right
spot....maybe right below a capacitance hat.

73 Tom