Fillinger@aol.com wrote:
>
> NigelCharles writes:
>
> > I see from his [Bob Nuckolls] reply to
> > you he now recommends RG-400 which doesn't appear to be available yet in
> > the UK catalogues. I would have thought that you should get satisfactory
> > results from RG-58 or RG-223 otherwise they wouldn't have been recommended
> > in the first place.
>
> I'm not sure we need much info more here, but FWIW, both Narco and King
> supply RG-400 for their xponders, and they say it's good up to 9 foot length.
> Beyond that, they specify something else entirely. RG-400 is less lossy
> than RG-58, but at 9-feet only a little. Also, the loss is greater at
> xponder frequencies, less so for VHF (where RG-58 A or C /U is fine).
>
> As a practical matter, transponders are more critical for IFR than for VFR,
> and they have more power (and sensitivity) than what ATC needs. There is
> more variance in power output among brands, proper installation, and
> out-of-alignment over time, so that the performance difference between RG-58
> and 400 alone is small in comparison.
>
> Regards,
> Fred Fillinger, A063
>
Cheers!
In the other hand, performance ain't all.
Forty years or so have taught me I'll be in there, testing for faulty
coax, or deteriorated connectors, or vibration damage long before the
set gives up. Perhaps Bob Nuckolls can tell us more about the staying
power of RG400?
What say?
Happy landings
Ferg A064
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