Not DCC

I've seen one of those before but the brand name escapes me.  Proprietary analog receiver.  Predates DCC by about a decade.

Scott Chatfield

ONBOARD or Dynatrol?

There are definitely some decoders that pre-date DCC.  Keller Engineering ONBOARD and Dynatrol come to mind.  I used to read about them in MR magazine in the 80's.

Here is link to the history of digital command control:

https://dccwiki.com/DCC_History

Thanks Scott.  I suspected it

Thanks Scott.  I suspected it was some kind of proprietary non-DCC controller after seeing the trimmer attached to it - and it sounds like you have confirmed my suspicions.

What about CTC-16? It's been

What about CTC-16? It's been a few decades since I had one of those decoders in my hands, but that looks familiar.

Digitrack or CTC16?

Could be a CTC-16 or a Digitrack receiver (predecessor to CTC-16), as it has logic on board, a servo driver, and the pot appears to be a channel selector to trim the channel it operates on. One IC is a counter, which is another clue. 

If someone has a CTC-16 schematic it might help identify it.

CTC-16

That's a CTC-16. I built the complete system. I could not find all the components to the driver boards and gave up on the system and any other systems of this caliber.  Keith Gutierrez introduced the CTC-16 in the late 1970’s. I also believe that there was a CTC-32.

Bernd

There was

A multi-part article in MR detailing the system in 1984, I think. I built three or four decoders, but then life got squirrely. By the time I rejoined the hobby in 91-ish it seemed like there was always something better on the way, and then DCC hit the fan.

Those pioneering systems were raw, but they clearly mapped out the needs.

B

I went with CTC-80

I had visited Bruce Chubb in the early 90s and he was promoting CTC-80 (a more feature-rich version of CTC-16). He gave me several CTC-80 receiver boards and I built a few of them, then ran a couple locos circa 1992 on the Siskiyou Line 1 in the very early days.

I had started the layout in May of 1991 and by summer of 1993 was well on the way to preparing the layout for the 1994 NMRA convention.

As part of the 1994 convention, some of the DCC vendors offered special pricing to Portland area layouts if they would install DCC in order to demonstrate that to convention goers at the 1994 convention. So I took the leap and moved to DCC in 1994 -- and haven't looked back.

ASTRAC

My first memory of any sort of independent control system was having a book that had a whole chapter devoted to ASTRAC. I was just a kid though and it was very early in my electronics education. I remember that seeming complex and almost like magic at the time. I'd have to check the timeline for CTC-16. I remember hearing of it but I'm pretty sure I was away from the hobby at that time, it was probably during the girls and guitars phase of my life. I also vaguely remember some people using Dynatrol.

Eventually I got clued into DCC and bought a Digitrax Challenger system, installed my first decoder in a Kato N-scale GP-50 and went from there. I stayed loyal to Digitrax for years and never even tried any other system until I decided to get back to my Ham Radio/DIY experimenter roots and began using Arduino's for DCC++.

I remember being fascinated

I remember being fascinated by Dynatrol, because David Barrow used it on the Cat Mountain & Santa Fe.