[R-390] Green gear

[KA9EGW]

If one knew the diametral pitch [DP] and tooth count on this gear, sourcing
a replacement should be easy [famous last words...].  Unfortunately I don't
have one; my 390A doesn't use it...

According to a number of different sources, to figure the DP you take the
tooth count, add 2, and then divide by the outside diameter in inches.  If
someone can supply this information, I would be happy to see if there's
anything I can do to help source replacement 'green gears' at cost-effective
pricing [i.e. cheap].  Hopefully it's a standard DP
[20,24,32,36,48...something like that].

73, Brian KA9EGW