Palomar Digicom 100 by CPI

[357]

I picked one of these up and was wondering if anyone has any info on it and the chip.
It would be nice to open it up to 40 channels or even 99


link to images

 

[nomadradio]

The EPROM in the pic translates the 8-bit BCD binary code from the front-panel knobs to the correct binary code for the PLL. The 5203 was made by a competitor of Intel, and used a different pin layout from Intel's ROMs. Intel's setup is what the rest of the industry copied and/or licensed. Pretty sure the 5203 was a Signetics design. If it fails, someone will have to hack a substitute of some sort. Can't remember the last time I saw a programming device that could write a blank one of those.

The PLL is composed of the 74-series logic chips wrapped around the ROM. Single-chip PLLs were just being introduced when this radio was designed.

I remember this radio as a good sideband performer, but a bit lame on AM transmit. Seems to me there was a hack to expand the channel coverage but it's been too many decades since seeing the last one of these.

The transparent cover of that kind of EPROM was usually covered with a label of some sort. I wouldn't expose it to too many weeks of indoor fluorescent light. They were meant to be erased by an intense UV light so they could be reloaded. They say a few days outdoors in the sun would do it. Indoor fluorescent light a bit longer.

73

 

[357]

Thanks Nomad. I was pretty sure you would know something about these.
Google shows very little.
Hopefully it has 99 already it will be here Monday.
looks similar to the CPI CP300

God Bless

 

[tramd]

Thanks Nomad. I was pretty sure you would know something about these.
Google shows very little.
Hopefully it has 99 already it will be here Monday.
looks similar to the CPI CP300

God Bless

Thanks Nomad. I was pretty sure you would know something about these.
Google shows very little.
Hopefully it has 99 already it will be here Monday.
looks similar to the CPI CP300

God Bless

Here's a schematic for it. I believe there is a CPI group on FaceBook that used to be on the old Yahoo group. Might find some info there.

 

[Dr_DX]

https://groups.io/g/CPIRadios

73'
Dr_DX

 

[357]

For your viewing pleasure...she's a runner

 

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[357]

 

[unit_399]

Really tight old school rig. Cleaned up nice.

Here's some background info from Radio Museum.org
$495.00 in '76 was a bundle .
(BTW - SCHEMATIC and alignment info in Sams CB-103)
- 399

 

[Big Kahuna]

That is really cool! Can you explain the channel selector knobs? That seems to be very unique.

 

[357]

She's a work in progress.
Looks a bit better. That switch though...I gotta find a LED or something the put there.
It only does A channels so it useless nowadays.

 

[357]

That is really cool! Can you explain the channel selector knobs? That seems to be very unique.

the left knob on 1 and the right knob on 9 would be channel 19.

The 1 knob skips 4 and 5 and added another 0 and a 1....not sure why yet.

I see I got to swap them back but 38 is 72 and it goes 5KC steps after a certain point.
I'm just glad it covers 40 channels because if it didnt I'd be screwed.
Someone must have made custom chips at some point

 

[357]

Here is the chip for the PLL and I'm happy to report it covers to at least channel 40
Radio is working but I need to find the ALC bad