[MilCom] Low Band Abandonment

[Tom M.]

My company is in the offshore oil business and we have a gaggle of helicopters.

We've also abandoned low band and replaced it with UHF/FM.

My thoughts are that the combination of 10W radios (Wulfsberg) combined with
embarrasingly short antennas of poor efficiency made for a poorly performing
system.  The base to base worked well but the helo systems did not.  The freqs
were in the 30, 33 and 49 ranges.

The antennas for the UHF radios (450 Mhz) are much more efficient and the
systems work better.  You can really count on line of sight with no skip.

I suspect Army helos might experience similar performance with low FM. 
Sometimes the freqs get covered up with skip from South American making the
problem worse.  If one could figure the frequency range in the 30-88 Mhz band
where the antennas worked best it would probably be much improved.  But then
each type of A/C (UH-60, A-10, etc) might have a different "best freq." 
Wulfsberg published antenna "gain" figures for our antennas and they were
atrocious, like -20db or something.

see

http://www.wulfsberg.com/PDFs/150-040017.B.pdf#search='wulfsberg%20antenna'

I could not get the helo manager to bite on my HF radio idea ;-)  It would be
difficult to explain the 20 meter presets!

Tom
Lafayette, LA

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com