[Milsurplus] PEWS?

[Facility 406]

I'm putting out feelers for PEWS (Platoon Early Warning System) 
parts/equipment.

I've seen four types.  The oldest, from the 60's, sends out beeps when 
it senses something, 1, 2, or 3 beeps.  I am NOT looking for this model.

In the early 70's, there was a system designated DT-578()/TRS-2

Research of the above brings up references to the more modern DT-577(V) 
series, which also end TRS-2.

I don't think the 577, and older 578 series are exactly the same 
internally/encoding-wise, but I don't know, having only the 577 on-hand.

I'm wondering what's out there that someone may no longer be interested 
in.  I once saw a set of '577 sensor boards going for $5, but didn't 
think to snag them to study.

I've attached some pics of the two types I'm looking for bits and 
pieces, or complete/functional if possible of.

Also attached, another type of magnetic sensor.  This is a pic I snagged 
from an auction listing about 25-27 years ago.  The price was incredibly 
reasonable, but the way it was listed, made everyone very, very nervous, 
it received no bids, and was never re-listed.

Anyone have parts of this 3rd, unique sensor system?

Or, anything similar to any of this?

Pics attached.

Thanks.

Kurt

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