CPattinson@aol.com wrote:
>
> Has anyone any thoughts on the fitment on antennae. I believe most are opting
> for the factory reccommended comms fit,
I didn't realise that there was a factory recommended fit, but antennas
are simple
devices and I did rush into this forum a while ago with some ideas. For nav &
com, a simple
dipole is fine, cut to length for the frequency and vertically polarised for the
com and
horizontally for the nav (although my handheld nav/com works well on nav with
the
antenna
vertical !).
GPS needs the makers antenna which should be mounted as recommended -
although
I suspect
that the flat plate type of antenna (as in the Flightmate)would work well if
mounted
inside the
fuselage at the highest point - has anyone tested this ?
> Have priced most of the commercially available aerials but they are
> horrendously expensive, also most tend to be for metal aircraft.
Everything for aircraft is expensive ! But with a little ingenuity one can
often adapt other
materials.
> The most awkward one appears to be the VOR as this is usually fairly large
It only looks large because you are seeing both sides of the dipole (in contrast
to the com
antenna which uses the metal fuselage as half of it)
> and needs to be mounted horizontally.
This could easily be arranged inside the bottom of the fuselage
> Does anyone have a design for a folded dipole suitable for VOR use (also
> possibly
glideslope) .
Why use a folded dipole when a plain dipole will do the job ? I have suggested
using braid
rather than plain copper wire as being less likely to break under the inevitable
flexing of the
structure.
> Im not a radio boffin so answers in plain English please.
Can't avoid some technicality - but feel free to email me direct and I will sort
out anything
which isn't clear !
> Also do the aerials interfere with eachother and therefore require spacing out
along the fuselage.
Apparently not, but the obvious locations would be com in the fin and nav on the
fuselage floor.
> Is the standard radio 50 ohm cable suitable for connecting all these radios up
Yes, but use the best quality you can buy as poor quality co-ax will absorb a
lot
of signal.
> or does the impedance depend on the frequency.
No, it's a constant
> Am nowhere near fitting any of these devices but am close to putting on the
> top.
Suggest that you don't use connectors but make soldered joints betwen coax and
antenna -
connectors inevitably corrode in the end.
> I would hate to think that I am going to be crawling about in the boot
> space to fit all these afterthoughts.
Yes, the same thought occurred to me !
> PS - How easy is it to get into the rear fuselage after lid on. Answers only
> from qualified Europa potholers.
Look forward to hearing the answers !
Hope this helps - as I said, feel free to email direct !
Martin
Martin W. Berner, 9Y4TAM,
26 Mayfield Road, Valsayn Park, Trinidad, The West Indies
Live long and prosper !
As a last resort, read the instructions !
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