I am restoring two Ocean Hopper receivers. One is labeled 223749 706031
706 and the other one is 83Y749 604020 604. They both have the same
component values and circuit diagrams.

The manual that I ordered online clearly states that it is for model
83Y749 but there are differences in the circuit diagram. Namely, my
version does not use a power supply filter choke, it was replaced with a
680 ohm resistor, and there are also a few differences in component
values. The chassises do not have the hole to pass the filter choke
wires so they were not modified by the builders. I wonder if anyone
knows all of the models and their circuit diagrams? Is the replacement
of the filter choke an earlier or later model?

I am currently working on the one labeled 223749. The receiver had a
lot of hum but I was able to clean that up by replacing the filter
caps. It currently "works" but not nearly as well as I remember. The
regeneration is very unstable, so much so that you can't copy CW at all,
much less SSB. I used one of these receivers in conjunction with a
DX-40 for years when I was first licensed and I worked all kinds of
stations on 80, 40 and 15 CW and of course on AM. It was the beginning
of SSB and I worked SSB stations as well. So I know it worked a lot
better than the one I am currently working on. My original one was
cannibalized by my brothers for some project so I don't know what the
circuit diagram of the one I had was. I am wondering if there were
other circuit changes or if it just some component problems. The
resistor values and voltages are all OK. Anyone have any ideas?

Larry

he manual that I ordered online clearly states that it is for model
83Y749 but there are differences in the circuit diagram. Namely, my
version does not use a power supply filter choke, it was replaced with a
680 ohm resistor, and there are

My two original schematics for the Ocean Hopper, dated 1940 and 1941, both show
the choke. Neither of them reference your numbers. The kit was identified as
B9800