Lectrosonics M175-LS VHF Mic Transmitter Teardown

[FenderBender]

I'm in the marching band at my school. Don't laugh we're actually pretty good...If you're curious:

Anyway,

Our director uses a bullhorn system for practice. Two bullhorns hooked up to a wireless mic. Well the mute switch on his transmitter broke the other day. The bat/actuator just broke off...so I volunteered to fix it.

It's not anything special, but if you were curious... Build quality is pretty good. I'd say you would call it "professional-grade" if such a grade existed. Not consumer crap, but not NASA grade. Lots of RF magic going on in here. Very precise crystal as you can see. 8 significant figures.

The big chip on board is an ON SA571D which is a compandor, a device which I had never heard of before, but is apparently widely used in RF transmission. Curiously, there is another footprint for another SOIC-16 package on the board, but as far as I can tell there are no better variants to the M175 so I don't know what it would be used for.

Anyhow, comes in a nice machined Aluminum case. The 9V battery system is solid. Can't put it in the wrong way either.

Seems like the original retail price for it was around $350USD. However, most of the places I looked have it for about $250. Still not cheap! But I guess that's the price you pay for a low-ish volume product that's reasonably good quality.

M175 Datasheet: http://www.lectrosonics.com/images/TD-sheets/m175td.pdf
SA571 Datasheet: http://www.onsemi.com/pub_link/Collateral/SA571-D.PDF