Perhaps your problems were not down to the antenna position. I have a
simple 'lollipop style' antenna built into a fibre glass moulding, with
ground plane. It sits on the left side of the fuselage floor, just aft of
the baggage bay. The transponder is a UPs/Apollo SL 70 and it has worked
well right from the start without any apparent blanking problems at all.
regards,
MP
----- Original Message -----
From: "Colin John Howard Richardson" <cjh.richardson@virgin.net>
Subject: Europa-List: Transponder Antenna
> <cjh.richardson@virgin.net>
>
> The original position of my antenna on a mono wheel was mounted on the
> back of the baggage bay with the lower end of the antenna about 3inches
> (75 cms) above the lower fuselage .
>
> I had serious problems with the polar diagram (ie poor operation) from 45
> deg left of centre, through the nose to 30 deg right of centre. Caused
> almost certainly by the landing gear and engine shielding the antenna.
>
> Would suggest the best place would be on the lower surface of fuselage so
> that the antenna can "see" 360 deg around and downwards.
>
> My transponder was the Terra unit feeding a Terra antenna.
>
> Hope this helps.
>
> John
>
> Monowheel now a tri-gear.
>
>
>
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