The Ameco CPO

Referring again to the recent buy of stuff from Ebay mentioned here:

https://wb9kzy.blogspot.com/2026/06/buy-first-think-later.html

I started fooling with the Ameco Code Practice Oscillator:

from the original listing

It looked a little grungy both outside and inside but it did fire up.  There are two holes marked N and P which must have been used for wiring to an external supply / charger.  Inside a mod was made to the battery holder (A Keystone, they still sell them !) to add a diode and two GE AA Nicads.  Of course the Nicads have leaked to the extent of having the wiring to the holder corrode off.

As a first step I removed all the screw and bolts from the front panel:

And then washed it with some liquid soap:

I think it looks OK.  Here's a photo of the CPO parts themselves:

Next step will be to replace that battery holder with something new - not sure if I should get the original Keystone or just use a plastic one.  I'll have to think about it.  OK, I thought about it:

That's the original (although now it's probably imported) but that's too much $$  :(

I took a look for N4MW's CPO page but it wouldn't load for me :(  But I did find a copy from January 2026 on the Wayback for this Ameco CPO, Model OCM:

https://web.archive.org/web/20250518104525/http://n4mw.com/cp031.htm

He had the documentation for download (nice) here:

https://web.archive.org/web/20250518104525/http://n4mw.com/cp031.pdf

BTW, the doc does show the diode installed on the battery holder so it wasn't part of a battery charger, not exactly sure what the function was:

Per this site:

https://www.radiomuseum.org/r/americanel_ameco_code_practice_osci_3.html

The OCM-2 was circa 1969 (maybe a little earlier ?), so I assume that the OCM was an earlier model.  However I was unable to find it in the Allied catalogs.  Making an assumption on price and date, here is an approximate inflated price of the Model OCM:

Figure the kit version was $10 with an approximated 10x in price the kit OCM would inflate to $100.  In either case it wasn't a cheapie.

Best Regards,

Chuck, WB9KZY
http://wb9kzy.com/ham.htm