ear.navy.mil>
> A couple weeks ago, Michael Harter, John King, and I flew to the Va.
>State Fly-in. I flew with John, in his plane, and we followed Michael. We
>flew off his aft stbd quarter (nautical talk) most of the way and Mikes
>transmissions were very weak and garbbled to the point, we could barely
>understand him. John said, they had experienced the problem before when
>flying in formation. We were well within visual distance of Mikes plane.
>If we changed position a little, the problem seemed to get better.
> Is this mearly a "positioning" problem? Both radios in question were
>built in and not handhelds.
It is not uncommon for closely positioned radios NOT to communicate
well with each other . . . the receivers are designed to pick very
tiny signals out of the etherial trash. After going to a lot of
trouble to hear the weak signals, the radio may be prone to overloading
from VERY strong signals. Try an experiment where you back off from
the transmitter that's difficult to hear in incerments. You may find
some separation where the receiver "recovers" and you can now hear
what used to be garbled. Further, radiation patters around an
airplane can have marked peaks and valleys in their intensity, you
may discover that your position in azimuth around the
> Speaking of handhelds, I saw in, one of the catalog's, an "amplifier"
>for handhelds. Are they worth the money to improve comms with a handheld?
>If I remember, they weren't cheap????
Generally these devices only boost your transmitter performance
although some may have receiving pre-amps built in too. By-in-large,
receivers in hand helds are nearly as capable as receivers in
panel-mounted radios when it comes to sensitivity. It may lack
capabilities in overload resistance but generally speaking there
is little gain to be realized by puting a pre-amp on a hand held
radio's receiver.
Transmit amplifiers will indeed make you heard further but there
are cautions. Low power hand held radios, because they are low
power, don't have to work so hard to suppress UNWANTED output from
their transmitters . . . and EVERY transmitter puts out energy
on frequencies other than the one you're using to communicate.
An amplifier will boost both the desired and undesired outputs
which may cause you to become a nuisance to folk using other
parts of the spectrum. An external antenna is much less expensive,
needs no power from ship's systems, and will generally let you
talk to any station you can hear.
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
http://www.aeroelectric.com
|