ELIPPSE wrote:
: DME and the transponder are in the 960MHz to 1215MHz range. At 1GHz,
: RG58 has 17.5dB/100ft., RG142 has 13.0dB/100ft., and FSJ1-50A has
: 6.0dB/100ft. If I was operating under extreme conditions, I would want
: the best performing equipment available to me. Sometimes 1dB can make
: the difference between getting a signal or not! Ask the guys talking to
: the spacecraft out among the planets.

That's a completely different problem than aircraft communication. Most of it
is ancient tech with fairly wide SNR margins, and your 4.5db/100' shinks to only
0.45db for a normal run of 10' in a GA aircraft. That's down in the noise (pun
intended) for signal degredation and about the same loss as putting a connector on the
end. IIRC the main reasons for RG142 are ruggedness (read: bitch to work with),
longevity (won't rot out in 40 years), and materials (RG142 on fire is supposed to be
at least slightly less hazardous than RG58 on fire).

-Cory
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* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
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