[NSRCA-discussion] 89 Nats

[Dennis]

Ok, for those that are still interested in what caused the radio
interference at the 89 Nat's, here is what Bill Bowen sent me.

Denny

After I got home last night I checked my old files on the Futaba lock
out problem at the 89 Nat's.  The problem was with the 9VAL system,
specially their new 1024 receivers. Interesting though there was only
one crash and everyone else regained control as the plane got low
enough.  As I mentioned I loaned them all six of my 8 channel PCM 512
receivers which were on 6 meters.  Steve Helms brought a team of 6 folks
in and did extensive testing twice.  What they found was two areas at
Vista field where high reflection from buried metal and was quite
noticeable in the receivers.  They deduced that the rejection
sensitivity was not only two small, but the logic for rejection took too
long to determine it was OK after the interference left.  Helms flew his
plane all around for days at Vista and could not repeat the situation,
but it was in September and much cooler than during the Nat's. They
recalled all of the 9VAL receivers and repaired them for nothing.
Somewhere I still have a T-shirt that says "I survived the 1989 Nat's
Lockout"".

Bill



Dennis Cone