How many R-20/AN-ARC-5 (1.5 - 3 mc), R-21 (3-6 mc) and R-22 (6-9.1 mc)
receivers are out there? I have one of each and there are no serial
numbers stamped on them.
The numbers stamped on the back are, in order, 5005, 5006 and 5007,
which are not the same numbers as on the R-25, R-26 and R-27. R-27,
for example has 9606 stamped on the back.
- Gordon White