> > europa-builder@ntlworld.com wrote:
> > > ...
> > > The antenna connector should be straight into the back of the
> > > radio/gps/what-ever. An additional connector (if that's what you are
> > > saying) may cause all sorts of SWR problems.
> > > ....
> >
> > What is meant by all sorts of SWR problems? The mfr data sheets for
> > coaxial RF connectors will specify the insertion loss, and it's rather
> > small (like 1.05 VSWR). I agree they should be avoided, but an inline
> > RF connector is often supplied by avionics manufacturers to facilitate
> > the installation. For a removable Europa panel, if an antenna
> > connection is part of the tray on any of the boxes, there will be no
> > choice.
>
> 1.05 is an addition which should be avoided. If you have a connector on the
> back of the device, why would another one be needed 12" further down the
> line (which leads to other problems, there is often a minimun length of
> cable specified between connections).
>
> Cheers,
> Mark.
Actually, 1.05:1 reflected loss is less than .1% loss in power! Those
some RF connectors are a bit more... Where the avionics box' RF
connector is a push fit and integral with the tray, one will need
another RF connector for a removable panel. At VHF frequencies, it
won't matter. At transponder freqs, there's more loss and spacing is
a factor, but both King and Narco still permit an inline connector.
King states a max of 6" from back of box to inline RF connector.
Best,
Fred F.
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