Thought there used to be an "avionics" subgroup, but I guess not.

Cross posting this in .products & .ifr.

This is a good test for those of you with Expermimentals, especially those of
the composite variety.

If you want a good real world test of how hardened your equipment is to RFI,
fly over to Delano, California and fly the pattern for 32L. That puts you
about 2 miles from the Voice of America Short Wave transmitters. The signals
blew out our digital tach! (A TinyTach unit, a popular small unit marketed by
Spruce.)

I did a quick Google search, and if I'm reading it right, they have a couple
transmitters with 500kW inputs. They also have quite an array of directional
antennas. I don't know if that puts them in the Megawatt range of Effective
Radiated Power when the antenna pattern is east - west, but I know our (now
obsolete) King Silver Crown radios go completely nuts there. (As defined by
strong foreign language broadcasts in the radios, Intermodulation Distortion,
needles swinging wildly.) As do our ANR headsets and our Insight GEM. (You
can turn the radios off and still pick stuff up in the headsets! The EGT bars
dance merrily on the GEM.) ACK ELT kept falsing. Thankfully Klaus' Lightspeed
Electronic Ignition doesn't seem to act up.

It'd be interesting to know just how many volts/meter are generated in the
vicinity. Wonder if a fluorescent bulb will glow?

Admittedly, in a Glasair (plastic) airframe, there's no shielding, so we're a
worst case scenario. Still, it'd be interesting to hear what some of you with
Glass Cockpits in shielded airframes experience. I wonder if the interference
is strong enough to cause a system lock up? Better to find out now than later.
If you find yourself north of Bakersfield, why not try the pattern at Delano
and let us know what happens. They have cheap fuel - and a good Mexican
restaurant in case you're grounded. (No pun intended.)

Mike Palmer
Excellence in Ergonomics