I
have built an additional limited quantity of the OH2GF inspired
Synchonous Detector / SSB Converter for the R-390 and SB-600 Radios.
This
unit is stand alone, it uses the 455Khz IF output supplied by the
radio. It also incorporates a small audio amplifier output for a
local speaker. It is self contained and requires no
modificatioins to the radio. Here is a link to the directions and
the article that inspired my remake of the adaptor. DEVICE INFORMATION
If
you are interested in purchasing one, the price is $295, this includes
the unit and a 12 power supply. Postage is extra the unit weights
3 lbs. Contact me at n3lll@kitparts.com ... tom