[MilCom] AWACS President Support * Low Power WT Range with AirborneUnits?

[Duane Mantick]

There are Amateurs who have worked some of the low orbit satellites
with handheld radios in the 5 watt range, using a portable beam
antenna.  I don't find it too hard to imagine using a handheld
to work a 30Kfeet aircraft.  In fact, if you look you will find
some airband HT's out there which, while presumably designed for
use around airports and helipads, etc., could be heard at a 
pretty good distance if good line-of-sight is available.  We
tend to think of 30,000 as a pretty good altitude but speaking
from the Amateur perspective we'd think that one mile is 5280
feet so 30,000 feet is less than 6 miles - many of our HT's can
talk that far without much difficulty.

100 miles?  That's a different can of worms.  That's why we have
repeaters.  :-)  Kidding aside, if you have line-of-sight clear,
the 2 meter band (144 to 148 MHz) can lend you possibilities for
that kind of range.  I have been on Clingman's Dome in the 
Great Smoky Mountains NP and used only an HT with rubber duck 
antenna to talk to someone on Mount Mitchell in North Carolina
which is a distance of 40 to 50 miles.  We did that on ONE watt.
5 watts out to 100 miles?  Definitely possible.  Going up into
UHF range the closest analogy would be the Amateur 440 MHz band.
You're much more reliant on line-of-sight than 2 meters but 
I suspect you can do it here, too.  I can't personally speak
to that because I don't have a 440 HT but so far my Yaesu
FT817 (long story - not an HT but a portable multi-band, multi-
mode transceiver designed for backpackers) has performance that
indicates it would be able to do something like that kind of
range.

So I'd have to give it a qualified yes.  Qualified due to needing
a pretty clear line-of-sight, which means your pattern upwards
would be kinda cone-shaped, point on the HT and opening up as
you increase in altitude.

Duane
WB9OMC


-----Original Message-----
From: milcom-bounces at mailman.qth.net [mailto:milcom-bounces at mailman.qth.net]
On Behalf Of Ken
Sent: Saturday, November 12, 2005 12:56 PM
To: MilCom
Subject: [MilCom] AWACS President Support * Low Power WT Range with
AirborneUnits?

AWACS crews watch over president
http://www.af.mil/news/story.asp?storyID=123012883

Interesting story, I would imagine that flying at 30K feet they also would
have been maintaining communications with the President Bush's security
detail, although the story doesn't specifically state this.

Wondering if you had a 5 watt portable VHF/UHF unit on the ground, would it
be feasible to talk with the AWACS @30K?  Also what kind of range would you
get normally (100 mile?)?

Ken






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