1966 Zenith console stereo

[Adam]

I picked this up off of craigslist today. The controls really need cleaning. The tuner works, both AM and FM. The amp works ok on the right, and isn't dead on the left, but comes out very soft so I can just barely hear it if I turn it all the way up. The record changer plays at the right speeds, but won't change records. If I turn it to reject, it just keeps on playing. Also the rubber pad the record sits is unglued, I had to remove it when I tested it so the record would sit flat. The hinge won't hold the door up like it should, but otherwise the cabinet is in great condition. It uses the early solid state chassis with the transistor sockets, and has 4 speakers on each side, should be a nice sounding unit if I can get it working.

[Kamakiri]

I flipped 3 or 4 of these from estate sales over the summer....tube powered ones though. I was picking them up at estate sales for $20-$40 and selling them for $100-$200 (I got $200 for an early 60s RCA in very nice shape). Did simple recaps on them.

There's a decent demand for working period-correct functional record players out there, if you're patient. Right now I have a Motorola that's doing the same thing yours is, with the lack of a reject function. In my case there's a small tip broken off the arm that actuates the reject function, so it's not really repairable without a parts unit....so I'm not going to bother.

[DavGoodlin]

That is a fine unit there. I have a 1969 Zenith ready for sale, almost finished except for the record changer doing what yours does, sometimes

One of the capacitors that couples the push-pull output transistors to the speaker is likely partially open.
This is a common problem with solid state amps. These also have a main/remote speaker switch and even a headphone jack that may need cleaned.

That is a common prblem with the record changer. There is a long, flat actuating rod that may have the one end bent. There is a good tutorial on how these changers work in Sams set 767. It is a good idea to lube these exactly as directed. I saved a few RCs over the years and Voice Of Music, which supplied them to Zenith, changed little so parts will swap.

The lid problem is easy, there is a screw on the bottom of the spring box that needs tightening. I just fixed a 1964 Admiral this way.

BTW, Kitty may be trying to help you on this one. A certain Ted Nugent album might motivate him/her.

[marty59]

Was Zenith still using that ganged volume/balance pot on yours? Those cause problems as you describe.

[Electronic M]

I have one where the tuner chassis is almost all tube, and the amp chassis is all SS.

[orthophonic]

That is a mid line model. Gary at thevoiceofmusic.com will have any parts you need for the changer.

The weak channel will probably come back with a recap.

[Adam]

I didn't know there was much interest in consoles from the 60s. I haven't had anything that plays 33 records in a few years, and decided it was time to find something. I wanted to try one of these early solid state Zenith consoles, and had been searching craigslist for a while. Most of what I saw was priced high, $100-$400 range, or was one of those 1970s units that weighs about as much as a hippopotamus and has all that plastic fake woodwork on the front, or both. I had kind of hoped to find one of those ones with the adjustable slats over the speakers and the pop-up reel-to-reel, but when I saw this one which was in a cabinet I liked, looked really clean, was only 50 bucks, and would fit in my back seat, I jumped on it. The guy I bought it from said it belonged to his mother, who bought it new, but hadn't used it in years (likely decades). The record storage compartment was full of old firestone christmas albums still in the original wrapping.

It's good to hear people think it's likely a capacitor, and not a hard to find output transistor causing that problem. It does use that weird vol/balance control. I think the way it works is one knob controls the left, one the right - neither is really a balance control. That screw is missing from the hinge. This model appears to just use these plugs that go in the remote speaker sockets, that short the connection. I've never had much luck fixing record changers, I'll have to see if I can dig up a copy of sams 767. That cat gets in anything and everything I'm working on.

My free time in the summer is almost up, so I won't have time to work on this for a while. I already pulled the chassis on my Philco 39-116 and set it out on my bench along with all the parts I'll need to fix it, so I can get right to it in the winter. So it depends on how fast I can recap and rewire that Philco chassis whether I'll get to this in December, or will have to wait until next summer.

[Findm-Keepm]

Search the archives - Doug Harland (DRH4683) posted about one he had that is similar to yours - he replaced the Callins capacitors to get his working IIRC. Callins caps are easy to identify - black body, red epoxy end. I've replaced thousands of them. They were the one weakness Zenith built in - every one eventually went bad. Don't fret on values - 15 and 20 microfarads can both be replaced by a 22uf modern type. You may also have the white Mallory caps - replace them too.

Cheers,

[DavGoodlin]

I was wrong on the sams number its 797, probably close to what vintage yours is.
Dive in to VM record changers, you can get pretty good if you look at several VMs first, before seeing another brand.
VM was used in Admiral, Philco, Motorola and Zenith. I have just started on VM's myself.

I first learned by working on older Magnavox changers for a dealer (Mag's players were made by Collaro) and got pretty good at it. I recently serviced an RCA changer and its very different also. They are all pretty good once you get them adjusted. Most of the manufacturers switched to BSR by the mid 1970s but they are not even close in quality.

[Adam]

I decided to fix this unit before the Philco. The bad coupling cap was actually one of those little 5uF ones in-between the two AF Amp transistors.

For now I'm thinking I'm just going to recap all the electrolytics under the chassis, but not the 1000 and 500/500/100 big chassis-mounted cans used in the power supply. I'm not into stuffing cans, and I don't want to reroute wires under the chassis if I don't have to. They seem OK, I looked at the power supply on the scope and the -44V source, the largest one, and it reads only about 0.15V p-p of ripple. And while that AC-line hum from bad filter caps in the power supply has been a problem in nearly every tube radio I've ever had, it just doesn't seem to be nearly such a common issue with solid state radios (or TVs).

[Adam]

So it was these little grey caps with blue writing that were bad, another one was causing problems with the stereo FM. Now that the radio works, tomorrow I'll put it back in the cabinet and look into the problems with the phono.

[zeno]

The Firestone Christmas records, every console stereo had
at least one in it.
Its a good idea to change the speaker coupling caps also,
if they go leaky can blow speakers and or outputs. IIRC
they are the ones strapped under the chassis. Dont remember
what caused no reject, I wasnt good at changers & stuck
to the BSR's & Garrards.

73 Zeno

[Adam]

I swapped all the coupling caps.

I touched up the alignment AM, and FM (on the FM the IF only), it didn't really need it, but I think it made a small improvement. I was concerned because it didn't get all that many stations on FM, but it turns out that was just because I was down in the basement hooked to some old rabbit ears. Upstairs hooked to the built in antenna it picks up loads of stations.

As for the record changer, it just hadn't been used in so long that the whole mechanism was seized up. I moved it by hand a few times to loosen it up, then tried it and it did reject on it's own slowly. If I want to take it apart and re-lubricate it, what should I use? Also is there a preferred glue to use to glue the rubber piece back on the top?

[Adam]

So I fixed the record changer. Those units are incredibly complicated, I took the whole thing completely apart and put it back together today, and I still don't think I get how all of it works. It was just hardened grease that was keeping it from working. I cleaned off the old grease and re-lubricated it with some of that white grease in a spray can, it seems to have worked well. I re-glued the rubber top on with just some regular super glue.

Now I just need to fix that hinge, so I can stop propping the door up with that blanket. I also picked up an 8-track recorder to go with this unit seeing it comes with the connections for a tape recorder built-in. But I have to wait until I get some 8-track tapes to check it out.

[Adam]

Now that I've used this for a while I've noticed a few problems:

1. After running for about 1/2 hour I get some hissing in the left speakers. Really only audible over whatever I'm listening to if I turn the volume way down. I'm thinking that this is caused by an iffy transistor in the amp (after the vol control, given the amount of hiss isn't affected by raising or lowering the vol)

What I would like to try is simply running it until the problem starts, then turning it off and swapping transistors left to right, and turning it back on - repeating the process until the hiss moves to the other side, thereby identifying what transistor is bad. (The hiss doesn't go away if I only turn it off for a minute or two - it takes about another 1/2 hour of being off).

But how do I tell which end of the transistor or socket is which without having to remove the chassis and trace the wiring? (This unit unlike Zenith TVs of the same era, is really difficult to get the chassis in and out of) I noticed there is a red dot on each transistor and socket which line up. But does the dot indicate the same end on every transistor and socket?

2. The record changer rejects when I turn the control, but not at the end of every record. It will however if I move the arm further to the center so it's right over the center of the record.

3. That 8-track plays tapes ok, but outputs no sound on the right channel. It's Realistic model TR-881, which is not even listed in the sams index. Any idea where I can get a schematic for this thing?