Trig TN72 Antenna

Greetings all,

Well, the TN72 is to be released shortly, and for those of us with Trig transponders this looks to be a great way to get ADS-B compliant. But... they recommend also buying a phenomenally expensive $300 plus antenna with it. Basically, it's this antenna he

http://www.aircraftspruce.com/catalo...mi11-14354.php

I see why it's $300 - after all, it contains an amplifier and yet can handles being exposed to god knows what placed on the outside of an aircraft. But we will no doubt be placing ours somewhere inside where they never get wet. So is there any reason why one can't sue this one?

https://www.amazon.com/Waterproof-Ac...+antenna+%2B5V

Both use the +5V to run a 28dB gain amp built into the unit. Not sure I want to spend $300 when I can spend $14! Possible issues are 1) technical and 2) regulatory, and I thought I'd test the knowledge on this board to see if I can't save a few sheckels.

BTW this could affect quite a few of us, so I'm really hoping that people with a good avionics/GPS level of knowledge could help us out here.