RFC

RFC was the original RF Clipper and quite possibly Datong's first product for the amateur radio market. It could either be purchased as a complete boxed unit or as an assembled PCB, RFC/M.

The RF speech clipping has also been used in commercial transmitting equipment - I have found a similar circuit in Parkair 1250 and 1400 air band transmitters.

Thanks the the late Jan-Martin LA8AK for tracing out the above circuits.

Inductors

I've had a query concerning the spec of the three yellow 10mm coils used in RFC and ASP.

There are no part numbers marked, but after some research in my old Ambit catalogues I came up with this information.

From the specs it appears to be a 10PA base - CAN1980BX.

Another page by Fritz PA0FRI with a schematic and some high-quality pictures.

M0EZP Datong Clipper Archive - More documentation and setting up details from M0EZP and G4FPH.