[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: REFLECTOR: Antenae

Reeder Graphics, Inc. wrote:

> I am reading some of the old Velocity Views and am alarmed by the
> analysis of the antenae included in the prebuilt wings.

If you put an accurate match efficiency meter on a certified aircraft's
standard whip antenna you would be even more alarmed.The RST systems di-pole
is normally twice as good.

The first five sets of wings we built, almost five years ago, were hampered
by carbon rudders which we eliminated.  My good friend Dave Black was one of
the lucky owners of these carbon infected com antennas.  It just so happens
that he is in the commercial broadcasting business were they need perfect
antennas for quality ground to ground communication.  An aircraft is much
different in that our antenna usually has fantastic altitude and commercial
grade transmission and reception is not mandatory.

We have done extensive testing with our $1,000 MB-500 SWR meter.  The
results of which showed that by adding 1/2" to RST systems com antenna
length we achieved a consistent reading across the bandwidth.   This
slightly longer di-pole has similar  readings as the great antennas made by
the knowledgeable Bob Archer ("Sport Craft") according to our in house
test.  We prefer the simpler RST di-pole because of easy installation and
less chance of delamination.

The Nav antenna has a yellow band  and the Com has a white band.  When your
use a whole saw to drill out the strobe light hole be careful not to drive
it home all the way into the com cable.   After opening this hole tug on the
cable and you can see which one it is at the other end.  A meter connected
to antenna cable will also respond to your hand passing near the antenna.

One more note:  Any sharp bend, anywhere in the cable, will severely hamper
the transmission.

Building an aircraft is challenging and fun because of what we learn in the
process.  Each problem is solved one at a time with no need to become
"alarmed" by what we learn or read as we go.  We just get as much knowledge
as we can and do our best as we go.  Always in the end we look back and
say,"I could have done better".  Details are often very important but on the
other hand Dan used to say something like: if you sweat the small stuff to
perfection the project may never get finished.  I guess the trick is knowing
when to sweat and when not too.

Alan Shaw