Posted: 6/29/2014 8:22:05 AM EDT
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Hey folks
I was cleaning some of my late step fathers stuff out of my garage and happened upon some radio gear. It looks to be cb related, but I ran across an old palomar 225 amp which I can't wait to play with. I also came across this device which I'm unable to determine a purpose. Is it just a frequency generator? It looks to be an old kit, but thought someone here might have some knowledge. Any help appreciated 
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It was likely built in 1996 and has a micro computer unit and a programmable timer / counter inside, among other smaller things. Way too advanced for CB... Looks cool, and if I had it I'd reverse engineer it just for fun!
ETA: The owner also thought it was valuable because it looks like he marked it with his ID info for LEO to help recover stolen property. My dad did that back in the 90's, something about your initials or something and part of your SSN . ETA: This isn't your box, but the CB1 Chatterbox Voice Recorder used that same MCU. Damn, maybe it is something for CB!  http://www.shopramseyelectronics.com/ramsey-electronic-manuals/CB1-manual.pdf Maybe you have a sweet echo box, with Roger Beep? 
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| Anything behind the main PCB? Any markings on the PCB? The 51074 is an 8MHz counter chip. The oscillator appears to be connected to the clock input on that chip. I can't find anything with google that points me to any clues about the F1B markings. The deviation and location markings on the front are very fascinating. |
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Thanks for the help folks. I greatly appreciate it.
I wish I had good info to report. I pulled the unit apart and there are no marking on the PCB board anywhere, the traces indicate to me this was a kit of some sort... 
I will have to take some time to see if I can determine what it's actually doing with trial and error. Again.. Really appreciate the help. |
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Just playing around here, but maybe I can add enough info to help someone else solve the mystery.
The shaft sticking out of the top of the box is a Bourns Rotary Optical Encoder. http://datasheet.octopart.com/ENA1J-B28-L00064L-Bourns-datasheet-11721189.pdf I can't tell for sure where the two switches on the right connect. The lower one with the red wires appears to be SPDT. The one above it appears to be SPDT also, but only half used for SPST. I assume that the 1/8"? jack at the lower left is for the power adapter? That appears to feed the 5V regulator that powers the logic circuits. Do the SPST switch and the power input connector use the same wire colors because it's a power switch? Or is it just coincidence and the switch is for something else? The BNC jack enters the board near the xtal osc up there by the encoder, but is the jack for input or output? Can't tell without tracing the connections and seeing what they connect to. Looks fairly easy to reverse engineer the hardware enough to make a crude schematic. The hard part would be to build an interface from that era to get the programming from the PROM, and then decode the instructions to determine exactly how it's supposed to operate. http://pdf.datasheetcatalog.com/datasheet/motorola/MC68HC705C8ACFN.pdf In 1985 I was 21 years old and knew nothing about computers, and bought a 1976 Digital Group Z80 computer at a hamfest for $40. This was one of the very first hobbyist computers ever made. When I got it home it didn't boot, but it came with the manual. Remember, this was way before the Internet and Google searches. I read the manual and learned the machine language of the Z80 CPU, learned exactly what that thing was trying to do and where it failed, and worked through that replacing some bad memory chips until it booted and worked perfectly. I then taught myself assembly language on the Z80. That all proved to be invaluable when I later went to college and then entered a career working on computers and related things. The same thing can be done with this little box if you want... ETA: Thinking of the power wire colors being the same as the switch wire colors, I now notice that the top right switch is labeled O / O on the back. On / Off perhaps? I wonder what the A / M for the lower switch means? Automatic / Manual? |
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The more I look at this things and the knobs, indicator lights, and the circuit it makes me think its a simple logic function generator or possibly a frequency generator as you originally suggested. A lot of the same settings are used on those devices.
Did your dad have an oscilloscope? |