Only the very last SP-600 variant, the JX-21A, ever had a SSB product detector. This one has selectable sideband and two additional tubes for a total of 22. Other radios used the really nice, rack-mounted, SPC-10 adapter. This plus the rack-mount SP-300 speaker make a nice impressive...
& T.M.C. CV-591A/URR$899.95SOLD Shortwave Communications Receiver TheHammarlund SP-600has coverage from 540 kHz to 54 MHz. Has workingS-Meter. Also includes the workingCV-591A/URRSSB adapter made by theTechnical Material Corporation. Receiver works, but external crystal capability unchecked. ...