[Lowfer] 500kc : FAA NDB antenna question(s)...

[Mike-WE0H]

Question from Brian...Can you guys help him out? He is not on this list 
but I will forward messages to him.

tnx,
Mike



Sorry for BW but I'm hoping one of you may have some first-hand
input on my VLF related question.

In short, I have seen several different types of NDB TX antennas
used at various FAA sites over the years.

Does anybody know, first-hand, why some sites use T-antennas while
others use center-loaded monopoles or wire cage antennas?

I'm sure it is a function of which vendor has a given GSA contract
at the time of site construction and site logistics, but was
wondering if one antenna was preferred by the FAA over another for
some reason that is not yet obvious to me.

I know the design goal is to provide a give field strength at
a given distance and modulation BW is a factor. Yet is one preferred
for NDB operation over another for some unique FAA reason?

-Brian, WA1ZMS/4