From an email to Repeater-Builder.....

Date: (Deleted)
From: (Deleted to protect the source)
Subject: An addition to the Two-Way Radio Keys Page

Hi,
 
I have information on one of your Motorola "mystery keys", the number 2154.
 
I was recently "demilling" or demilitarizing some US Air Force radio equipment prior to its turn-in to DRMO (Defense Reutilization and Marketing Office) for sale as military surplus.  Unlike most military base mobile radio managers, I do not believe in taking a sledge hammer to radio equipment as the method of choice for demilling.  Instead, I open the radio up and pull the crystals or channel elements for the previously assigned military frequencies, so the radio can no longer transmit or receive.   On the newer synthesized radio equipment I have the technicians overwrite the previously programmed military frequencies with a blank transmit frequency and the local NOAA Weather frequency for a receive frequency.  The net result is that the radios can no longer operate on military frequencies, but they still retain some value for DRMO sales to amateur radio operators.  As I mentioned previously, most USAF base radio shop managers (non-hams) prefer to simply bust radios up with a sledge hammer so they can be "red tagged" as "Saleable Quality Scrap".   After that action, there is very little monetary value to be recouped by DRMO through their sales program.
 
Anyway, yesterday I was demilling several Motorola suitcase repeaters.   As part of the process I always check inside the pouch attached to the inside of the suitcase lid to insure all military paperwork, call sign lists, frequency lists, etc. have been removed.   Usually the base radio technicians have already pulled any useable power cords, or other accessories that might be of continued use before I receive the equipment for final processing and DRMO turn-in.   However, one suitcase repeater had been turned directly into my office by the previous organization following their conversion to digital/narrowband/P-25 compliant radios.   Inside the zippered pouch on the inside of the suitcase lid there is another small pouch with a snap cover.   It usually contains spare fuses and an Allen wrench for adjusting the provided mobile magnetic antenna.   However, inside the small inner pouch of this particular completely intact suitcase repeater I found a pair of 2154 keys.   I confirmed that they operated the lock on the other similar suitcase repeaters as well.  All three suitcase repeaters were of the same model and vintage.
 
Specific Information (from the equipment itself and our military records):
 
Item: Motorola Suitcase Repeater (black case, chrome latches)
P/N:  P43SXS3180BT
S/N:  All three suitcase repeaters had a pattern of "570A(letter)(letter)(4 numbers)
Band:  VHF
Encryption: DES
Original Purchase Date:  01 February 1987
Original Purchase Cost:  USD$9,458.68
 
 
I hope this information helps fill in one of the blanks on your "Two-Way Radio Keys" page.   I found it when surfing the "http://www.repeater-builder.com" web site during my lunch hour.
 
73 de   (Name, amateur callsign and military base name deleted to protect the source)
 
Base Land Mobile Radio & Radio Spectrum Manager

THANKS to (name deleted) for the above info, and thanks for taking the time to write. And Thanks a third time for caring enough to demil by rewriting the frequency information rather than sledgehammering it.