wrote:
: You must be one of the few that has ever had a tube crap out. You
: will surely run out of gas before you run out of tubes.

: Having it on also allows all the toy collision avoidance things to see
: you.
: Like TCADS.

: Small price to pay for collision avoidance. Please have it on. It's
: not just the rule, it's a great idea!!

It's not that the tube craps out in-flight... it's just that repeatedly running the transponder when you do not
"need" it (read: in B.F.E., VFR, local-flights) means that you shorten its useful life when you *DO* need it (flight
following, Class-[ABC], IFR). Any time I actually *GO* anywhere where collision avoidance might be an additional
feature, chances are it's a cross-country flight and I'll have it on for that reason.

As I mentioned, I have personally gone through two tube-based transponders in this manner. My mechanic has
also gone through two that lost transmit power due to a dying cavity tube, as has another pilot friend of mine.
Granted, I'm on the low end of the avionics totem pole (ebay specials mostly)... the fact of the matter is that
replacing the cavity tube has been made cost-prohibitive by the part costing $500 or more.

-Cory

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************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
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