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Saber I with Mystery Board installed - Need help identifing

Posted: Tue Dec 25, 2012 11:30 pm
by n6fnp
I have a Saber I that wasn't putting out any audio from speaker and only works with a speaker
mike, so I opened the radio and saw that it didn't have a speaker inside, but instead had a small
PC board with wires going around the side to the back of the radio.

I'm real curious as to what the board could be for. It has a wire going to the man down button.
I thought it might be an aftermarket encryption board, but when I press the man-down button,
the transmit audio is not effected at all.

Below are pictures of the board. It looks like is from the early 90's based on the IC chips. Most
of the IC's have Motorola markings.

Image
Image
Image


If anyone can let me know what this board was for, I would appreciate it!

-Thor

Re: Saber I with Mystery Board installed - Need help identif

Posted: Wed Dec 26, 2012 7:38 am
by KB2ZTX
Could it be an internal man down board. Ie: radio tips over for so long then sends the man down alert ?

Re: Saber I with Mystery Board installed - Need help identif

Posted: Wed Dec 26, 2012 8:01 am
by Jim202
My guess is that it is some sort of ANI board. Seems like a whole lot of wires though.

Jim

Re: Saber I with Mystery Board installed - Need help identif

Posted: Wed Dec 26, 2012 10:57 pm
by AEC
I concur with Jim, it looks like an ANI board, or at least a tone board for select-5 operation.
Since all Sabers were able to use PL/DPL, there were models that were not able to generate all tones, this board may be what enabled the radio to encode/decode such tones.

Also, an LM324 is a Quad-Op amp, rarely used for secure voice.

The 8 pin DIP, appears to be an EEPROM, (94C30xx)
These tiny EEPROMS were comonly used in the old AMPS cellular radios for NAM/ESN storage.

Use of the secure toggle tells me it is a selectable option, and of aftermarket installation as the wires are messy and not secured, nor are they laid out properly to avoid shorts.
Sloppy work for sure.

I wonder what frequency the cylindrical cryastal is....3579.545 colorburst maybe?