RadioBanter - View Single Post - Current in antenna loading coils controversy

October 30th 03, 05:51 AM

oSaddam (Yuri Blanarovich) wrote in message ...

Any experiences out there, rather than more "reasons" why it ain't so?
Proper accommodation in modeling programs can give substantial improvement in
loaded elements modeling.

Let the games begin :-)

Yuri, K3BU

Dunno, I think it varies. But I sort of agree with Tom, I think it's
fairly constant across the coil. The reason I think so, is because the
electric field across the coil is also constant, and I can easily see
that using a fluorescent bulb across the antenna and coil. Sure, there
may be some decrease, but that could be due to wire resistance loss.
Also, the construction of the antenna itself could vary the current
across the coil. If the whip is top loaded, and the current would be
linear up the whip anyway, I would think it would also be linear
across the coil, no matter where it was. If the coil were base loaded,
with the sharply tapering current distribution up the whip, the taper
across the coil *might* be more. Another reason I think it's fairly
constant is because if I elevate the coil up the whip, I also elevate
and improve the current distribution. The current will be fairly
constant all the way up to the top of the coil, and then start to
taper off as you go up the "stinger" part of the whip. If the
distribution were not fairly linear across the coil, I don't think you
would see this. I'm sure it's not perfectly linear, but I think it is
for all *practical* purposes. And like I said, probably can vary from
antenna to antenna. I haven't read the eham thing yet, but I guess
this is my wishy washy vote... MK