[Lowfer] helix house?

[John Davis]

>
>Does the loading coil radiate?  Should it be exposed (in terms of RF)?  Or
>can I put it inside my steel building along with the amp?


The loading coil radiates, but its contribution to field strength is only
the same as a piece of wire having the same straight-line length from
terminal to terminal.  The real questions here are whether being in a metal
enclosure is going to detune the coil and/or reduce its Q factor (others can
probably address that point better than I can), and where you consider the
output terminals of the transmitter to be.

If that is the same as the output of your amplifier, then the loading coil
is part of the antenna system; in which case, the leads from the amplifier
to the coil, the length of the inductor, and the wire to the rest of the
antenna in the outside world all count against the total 15 meter limit.
Since part of your antenna is therefore inside the metal building, that's a
pretty big hit on performance...not to mention having high-voltage RF
floating around in the building too.

In short, I'd get the loading coil outdoors and keep the antenna side of it
(where the highest voltages are going to be) well clear of the building.

73
John Davis