Servicing info on RCA U70 UHF to VHF converter

[Bill Cahill]

Please replace electrolytic capacitors, first. Also, the ceramic capacitors do have some tendency to short. I've even had shorted disc capacitors. Let me know how it works. I have bad experience of poor reception with U 70. Thanks.

[Jonathan]

Bill,

I'm definately going to replace the electrolytics. I'll test resistors for drift and ceramics for shorts. Do the germanium diodes go bad too? I'll lubricate the tuning shaft and clean the contacts in the selector switch and replace the lamp if burned out. From what I hear, the U70 is a nice converter and works well, but from the looks of the tuner, misalignment looks easy to do. The bad reception could be because of misalignment, but I'm not the one to ask.

Thanks.

Jonathan

[Bill Cahill]

Sorry for long wait. Yes, they do often go bad, but, usually from leakage. What doesn't help is they started off leaky when new. Your'r on the right track. If you find another complete one, please let me know. Want one. Bill

[Steve McVoy]

These converters have no RF amplifier, and feed the UHF directly into the mixer diode. As a result, they have horrible noise figures, and perform much worse than a modern TV set (or VCR) in weak signal areas. If you live close to the transmitter, they work fine.