I just scored a fairly nice RCA U70, which is in a wooden cabinet. It seems to be a more substantial design than most, having a 2 stage "IF" amp which appears to be tuned to ch 5 following the 1N82 mixer diode. It has the usual set of three 300 ohm terminals in the back; "VHF antenna", "UHF antenna" and output to set. The odd thing is that it also has what appears to be an "SMA" connector labeled simply "UHF" on the back very close to the UHF tuner. I can get a UHF signal through the converter ONLY by using the SMA connector.
At one time there appeared to be a thread about this converter on the old AudioKarma site, but I can't seem to get to it... Any suggestions? Any info would be helpful.
jr