For Jim Weir: Transponder Installation

"Ron Wanttaja" wrote:

The current antenna location is precisely 4 inches below my heinie,
and I'd
just as soon get it further away, thank'ee.

Hazard to human tissues is related also to time, which for an xponder
means duty cycle also. They xmit for 21 microseconds each time reply
light blinks. Even at 250W and at that distance, should be less
effect than a cell phone next to your head. See
http://n5xu.ae.utexas.edu/rfsafety/ for an RF Safety Calculator and
links to tech discussions.

I'm presuming the best
approach would be to tin the wires, slide them into their locations,
and
solder them in place? Should I be using shrink tubing on each
connection,
too? (the connector itself has a strain relief).

If the DB-25 pins are "solder cup" type, they work by merely by
inserting wire, heating pin cup, and let solder wick itself in. If
crimp-type, crimper is better, though for thin wires and if properly
secured, soldering I think is OK. Shrink tubing is good if solder
cup and thin wires for a little added anti-flexing of the wire. If
soldering to tabs with a hole in them, definitely shrink tubing if
connections are exposed to shorting by metallic FOD, which can find
its way there under Murphy's Law.

When the installation manual shows the pin assignments for the DB-25
connector, the assignments are as if I am looking directly at the
connector
on the transponder...right?

Any ambiguity here is easily checked with an ohmmeter set for at least
2K. Grounds of course will be common to the box. Ohmmeter between
+14V-in and ground will show a reaction between infinity and some
resistance when switched off/on. Usually see increasing resistance as
the ohmmeter charges a capacitor.

Fred F.