-----Original Message-----
From: Eric Lemmon [mailto:[EMAIL PROTECTED]
Sent: Wednesday, January 05, 2005 8:53 PM
To: [email protected]
Subject: Re: [Repeater-Builder] Mobile Repeaters?
Mike,
I congratulate you on supporting the recovery from the 9/11 attack on
the Pentagon. But, please explain how putting 110 watts out of a
repeater has any relationship to the reduction of transmit power on the
portables. I should think that lowering the repeater power to 10 watts
or so would reduce the desense potential in the repeater, allowing the
portables to use less power.
<..........Simple.. the repeater was in the comm trailer in the parking
lot.. at the crash site. Now the handheld radios are not required to cover
the several miles. Instead, only a distance of approx 300 yds. The
repeater made the trip back to the Incident Command, not the hand held. So
less power was required.
In my experience, the coverage area of a repeater is always limited by
the ability of the repeater to "hear" the distant mobiles and portables,
not by a lack of power in the repeater's transmitter. An omni antenna
of modest gain, atop a 40-foot military surplus mast, will usually
provide ample signal to a temporary repeater, even from 400 mW
shirt-pocket portables.
<..........True... but we were allowed few items into the area. Everything
that went in... had to come back out with the same individual who took it
in. We tried to keep it simple for the volunteers in the impact area. Just
a hand held and a spare battery or two, plus water and a jacket.. And were
searched coming and going every shift. Nothing like having a couple of
SEAL'S point a MP5 at you just because they wanted to open your pack. It
was a very difficult set of circumstances under which to perform our
tasks...
It was most difficult to get a signal from the center courtyard area out of
the building. That is where the temp morgue was in place. So that station
was an exception with a deep cycle battery and a mobile rig. Although he
had a rough time finding a "mount" for his magnetic mount antenna. Keep in
mind there are many layers of shielding in the very walls of the Pentagon.
<..........Now in the parking lot we had pretty much complete freedom to
erect anything we needed. So we put the repeater in a travel trailer
located in that lot.. There was a ton of RF flying around.. all the Govt
agencies involved eventually showed up with their own comm vans.. and put
then INSIDE the fences... definite advantage!!
<..........Sorry I was not clear in my original description of the event.
It still get me stirred-up to think about it.
<..........mike
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