Black Message Box

Digital Message Device (DMD)

© Brooke Clarke 2010

Black Message Box
Click on above image to get a large version
The cylinder at the top holds three AA batteries.
Black Message Box
The connector mates with an AUDIO/DATA U-229 type
on a radio.

Background

I'm calling this a "black" message box because it has no ID markings of any kind.  In the Radio command menu is mentioned "DMD" so this may be called a Digital Message Device.  Some other DMDs are:
PSG-2 TM 11-7440-281
PSG-5 TM 11-7025-244
PSG-9
OA-8990/P
AN/UAS-12 ?
Nokia PARSA

Operation

This unit was designed to be mounted on a radio using the four captured screws on a hole pattern that's 8-1/8" x 3-1/2".

If you know of a radio with this hole pattern or have any info on this unit please let me know.

When it's turned on (and after the LCD contrast is adjusted using <shift> and the up or down arrows) the LCD displays:
Radio status menu   <<  ^  v  to  scroll  >>
                              << ENTR to select>>
v     << Radio Status Menu  >>
Radio Status Summary: No response from radio
Activity Monitor: Epoch time:, Msg status:
Past Epoch Status: No response from radio
Link Quality Check: Is radio in NORM? YES: No response from radio
Antenna Tune Quality: No response from radio
Interoperable mode <<  ^  v  to  scroll  >>
                              << ENTR to select>>
Prepare message for Tx
Radio command menu <<  ^  v  to  scroll  >>
                              << ENTR to select>>
Execute radio self test: No response from radio
Set time of day: No response from radio
Initiate EFB mode: No response from radio
Erase ALL radio messages:
Execute DMD self test: Running Rom Test, running Xram test, keyboard test,


The Time Of Day (TOD) is set into the radio , not into the DMD so it looks like this is not a crypto box but rather just a message sending (receiving?) box.

Links

Mike Murphy

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page created 4 Nov 2010.