[time-nuts] looking for data on time code display

Steve Byan stevebyan at verizon.net
Sun Dec 11 10:06:47 EST 2011

A while back I picked up a couple of what Fair Radio was calling "data line filters". They have a six-digit Nixie time display (hours, minutes, seconds) and apparently decode and display some kind of analog time code (IRIG, maybe?). It was made sometime in the early 70's; it's wire-wrapped with some op-amp filtering and a bunch of TTL for the decoding.

The front panel controls are:

rotary switch marked "input filter"  with positions: 250 Hz, 1000 Hz, 20 kHz, 40 kHz, 80 kHz.
toggle switch marked "1000 Hz" and "250 Hz"
toggle switch marked "reverse code control"

The rear panel has BNC connectors marked "input" and "output".

A yellow sticker on the side says:
Ft. Meade
DTID: H9823190045862
NSN 6625003684180
User ID: HI90159

I bought them with the intention of scavenging them for parts, then later considered making a Nixie clock out of them. But if I can get a clue as to the time-code they understand, I'd now like to restore them to operating condition. Anyone have any info or even speculation on these ?

Best regards,

Steve Byan <stevebyan at me.com>
Littleton, MA 01460

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