[Jeffhs]

I'd clean the bandswitch contacts if you're losing audio on either AM or FM and have to jiggle the switch to get it to work again. I have a Zenith C845 that had the same problem; cleaned the bandswitch (and the volume and tone controls while I was at it, as they were quite noisy) and the trouble disappeared. The radio sounds wonderful now, typical great Zenith high-fidelity audio from its 2-speaker system.

Your X-334 will sound great too, once the issue with that switch is resolved and the controls cleaned, to say nothing of replacement of doubtful capacitors, especially the 3-section filter cap in the power supply (the last if you hear any appreciable hum in the sound, although in a radio this old--43 years if yours was made in 1967--it wouldn't hurt anything to replace the cap on general principles). Zenith (the original Zenith Radio Corp. of Chicago) did not make junk; quality was their middle name and, for decades, their slogan was "the quality goes in before the name goes on."

I don't recall if the X334 had a selenium rectifier or not. If it does, I'd replace the stack with a silicon diode (1N4007) and a series dropping resistor to insure that the B+ voltage at the output of the new diode rectifier is identical to that from the selenium.


The X-334 was probably introduced shortly after the last runs of the K-731 (the latter, in the Early American cabinet, was produced and marketed until, IIRC, 1965 or thereabouts, the console-TV cabinet style [with short legs] probably being introduced in '64 or so). The front panels are similar, with slight but obvious differences, such as a vertical tuning scale on the X334 as opposed to a horizontal one on the K731, slightly different style of knobs, but the band switch on both is a three-position unit for AM, FM-AFC and FM.

I'm not sure, but I think the X-334 had a dial light, whereas the K-731 did not. The same applies to the C-845 series of the late '50s through 1960; the C845 did not have the dial light, but later models (C845,C845L/M, et al.) did use a pilot lamp, probably an NE-2 or NE-51 neon bulb. Since these radios were made in the '50s, with the last ones appearing in 1960, however, I would think an NE-2 bayonet-base neon bulb was used as a pilot lamp. I don't think the NE-2 (a very small bulb with wire leads) was introduced until well into the 1960s.