Higher end wooden Zenith solid state radio
 

Got this late '60's wooden Zenith AM/FM solid state radio w/ air suspension speaker off of ebay. The model tag is missing; but, I think it's from the "Z" line, which would make it a '69 model. The radio works well except for a speaker rattle, which I hope I can fix because finding the proper speaker for this radio might be difficult. I'm sure this was one of the last "real good" Zenith table radios that was made before they shifted production to foreign countries. I did slip off the back cover and the IF strip appears to be on a PC board while the rest of the set is handwired.

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Your Zenith radio could very well have been one of the last American-made solid-state sets manufactured before the company's radio division left Chicago for Korea. Yours looks like an offshoot of the model that looked like a miniature console. I recently saw a picture of a set almost identical to yours on eBay; these don't turn up very often, but yours is living proof that there are still a few of them left.

The rattling speaker may be something as simple as a particle of dirt having gotten between it and the cabinet. Does the speaker rattle at all volume levels, or just at high volume?

I would try to repair the problem first before thinking about replacing the speaker, as these air-suspension speakers are or could be quite rare nowadays; I'm not sure if any of today's Korean, etc. radio manufacturers even use this type of speaker mounting arrangement anymore.

Your radio's model number and chassis number tag could be that little bit of paper that's showing behind the dial in your picture of the set.

IF strip on a PC board while the rest of the radio is hand wired? Hmmm. :scratch2: Strange, IMHO. I would think that if Zenith went to the trouble of hand-wiring most of the set on a metal chassis, they would have done the entire set that way, including the IF amplifier stages. Somehow, I cannot imagine Zenith--even toward the end of their production of SS radios--doing something like that. After all, most of their older tube-type radios were 100-percent hand-wired on solid metal chassis; I didn't think they started using PC boards until at least the '80s, and they never, to the best of my knowledge, mixed PC boards and hand wiring, at least not until your set came along.

The speaker rattles at anything above a whisper volume control setting and mainly on FM where the bass is heavier. I will attempt to repair it if possible.

I've got a '67 plastic solid state Zenith clock radio that's built on a steel chassis with plug in transistors. I have a '69 Zenith SS radio that I got from my uncle when he passed away that's built on a PC board chassis that's riveted to a metal frame, IIRC. Then, I've got the higher end Zenith here.

As shocking as it may seem, I have a '50's Zenith tube type AM clock radio that's on a PC board chassis. Imagine my shock when I found that.

Zenith did make handwired TV sets up into the '70's. The early solid state ones used PC board modules that plugged in to a steel handwired chassis that looked like a tube chassis. These were probably the best solid state TV's that Zenith made. Then, the vertical chassis chromacolor II's came out. These still used PC board plug in modules on a handwired chassis. Then, the System 3 chassis came out in '78. This chassis consisted of near 100% modular PC board construction and the modules were connected via cables. The last vertical chassis CCII's with the handwired chassis was made in late '79. There could have been some made in early '80; but, Nov, '79 is the newest one I've seen.

The small thumbnail attached to this post is the Zenith radio I mentioned in my last post that looks like a miniature console, and is probably the predecessor to yours. Grabbed the picture off eBay a few minutes ago. As I said, I guess there are still a few of these sets still in existence--this one, and yours of course, are living proof of that. I'm happy to see that these sets are being saved from certain death in landfills, as most of them have only minor problems the owners don't want to or cannot fix themselves.

Hmmm. :scratch2: If the speaker in your set rattles even at very low volume, I'm not sure what could be causing the noise. I'd check between the speaker and the front of the cabinet first, in case there may be something stuck in there that moves when the speaker cone does (as I mentioned in my previous post). That failing, I'd look at the cone itself, as it may be rubbing against the speaker frame at some point; since the rattle is present at all volume levels above a whisper (!), this seems very likely.

I honestly do not think the rattle is being caused by anything else; in fact, it would surprise the dickens out of me if a chassis fault was causing this problem. I can't imagine how such a fault could cause a speaker rattle, unless the output transformer, if there is one, is intermittently breaking down to the frame and arcing; you would hear a noise that sounds like static, even on strong stations, if this were the case. However, if the radio basically sounds good as you mention, I would check the cone for starters. I wouldn't be surprised if that's the trouble.

I would also check the cone for tears, rips or other damage. A torn speaker cone can cause very exasperating rattles whenever it moves; also, if the speaker has been repaired by the former owner, the tape used to patch the rip could well have dried out and become detached, again causing a disturbing rattle at any setting of the volume control.

Good luck. That radio is well worth saving, as it was probably, even likely, one of the last quality radios made by Zenith before they went out of the radio business for good. The very last radio Zenith made that could be classified as "high fidelity" was built in 1982, and was the model (I forget the model number) that had a tuning meter and separate bass/treble tone controls. This was also the end of Zenith's good quality stereo systems, IIRC; I had a 4-mode integrated system, also made in '82 or maybe a bit earlier, that had tuned-port speakers and 5 watts per channel, but it was made in Korea, probably very shortly after Zenith's radio and audio division split the Windy City for the Pacific Rim. :no:

This small set (Zenith's last table radio) also had what Zenith referred to as a "bass booster" on the back cover, although I think this was little more than an air chamber that contributed little (if anything) to the overall sound quality. This radio looked much too small, IMHO, to be a true high-fidelity set; the speaker was probably too small for good bass response as well.

I had a couple of those 50s clock radios-I thought maybe I was just imagining them being cheap! Got rid of them a long time ago...or maybe they are just buried in that pile up in the attic!