>I have one local airfied (one frequency) that always cannot hear me when
>I try to land. I thought that my radio was broken the first time but
>last week I was there and tried to call them as close as 3 miles and
>they reported that I was unreadable. I immediately called up my home
>field which was 30 NM away for a radio check and was reported reception
>5.
The trouble with aircraft antennae is that there is always a compromise to
be made. I believe that a dipole will always be best because it has a
flatter polar distribution than any other but its always affected by the
airframe and its metal parts. My L9ong EZ would receive London Volmet while
not far from Paris Framce, 150 miles? usually around 4 or 5,000 feet. That
had a bent dipole in one winglet. SWR around 1.6 to 2.5 depending on
frequency. Problem with the Europa is the large lumps of metal like the
rudder and elevator pushrods close to the high voltage end of the antenna.
I once put my own (cheap) VSWR meter across a Bob Archer antenna and wasn't
too impressed, however the owner tells me it always works well. He has an
Icom handheld plumbed in.
There are many variables in this equation, not least the frequency accuracy
of the installation. Antenna installation can affect the frequency
transmitted and received by the set installed. I would guess, however that
o good homebuilt installation will usually be better than most certified
aircraft.
Graham, slightly tipsy, Jim Price arrived here today so we had a great
evening , especially after he got a ride in Glenn Waters beautiful Berkut.
Best homebuilt I ever saw.
|