What Model of Zenith is this Anyone Know?

[doity]

Picked this up today and it is working but the belt had melted, badly. The only model number is on the bottom and is listed as F712. But I cannot find anything remotely like that on the internet and this can’t be the only one. Can it? It has a very unique look so I was hoping that someone might know more or know if the ‘Allegro’ belt might work. Thanks

 

[Circular Vibes]

I do not know the model but it does have a very attractive look. I would clean all of the belt goo with isopropyl alcohol and head over to Turntable Needles and follow thier directions for replacing the belt. Basically take a string and a marker, wrap it around the flywheel and motor, mark string to measure the length, consider a belt that is between 5 and 10 % smaller than your measure and decide what width and thickness you need. If all else fails, email them, thay are very helpful I've heard.

 

[doity]

I found a Zenith Allegro quad unit just like it but it had a integrated turntable. Either this was a standalone piece or it was modded but I doubt the latter.


Luke

 

[4-earredwonder]

Picked this up today and it is working but the belt had melted, badly. The only model number is on the bottom and is listed as F712. But I cannot find anything remotely like that on the internet and this can’t be the only one. Can it? It has a very unique look so I was hoping that someone might know more or know if the ‘Allegro’ belt might work. Thanks

Not to sound pessimistic, but I'd be concerned what internal forces had caused the belt to melt. Belts stretch/wear out, even break from normal usage....but MELT?

 

[doity]

Well not ‘melted’ but once grabbed onto melted away. I guess 45 years will do that!

 

[Circular Vibes]

Rubber disintegrating to goo is a common occurence for anyone who has worked on a cassette/8 track/open reel deck that is not direct drive. It can be very messy and get into places that defy cleaning like the change mechanism of an 8 track deck or on the head and inside the track change sensor.

 

[4-earredwonder]

Found this little tidbit of info on one of the AmazonUS links:https://www.amazon.com/Zenith-Track...3?keywords=zenith+belt&qid=1569216100&sr=8-23


**NEW REPLACEMENT BELT** ZENITH 8 TRACK PLAYER in
Clarion 4 Channel All In One Cabinet by Morse
… if you need a belt for any power tool, appliance, or electronic item...send us an email.WE'VE GOT IT!!
*NEW BELT* 1000's of satisfied customers

The vendor is westcoastresale

 

[doity]

I found another model number inside......169-471. But looking at the service manual for that unit it had a turntable on top and a dust cover. Mine has neither does it look like either had ever been there previously. No hinges, scratches or indentations where a turntable would have been. Odd.

 

[Circular Vibes]

Doing a hasty Google search, the 169-471 number is the chassis for the 8 track deck and F712 is the model number of the whole unit. Sams website shows the tape chassis to have been used in many models. The F712 model came in variations. There wasF712W, F712W1, and F712W2. If yours had come with a record changer, you would know it by the big weird shaped hole in the top. Maybe the other model numbers denoted what accessories, like changer and speakers it came with. Here is a picture of something similar with your tape deck in it. You can date your machine approximately to 1974 with this.

 

[doity]

Thanks CV! I also found an old advertisement for the current line of Allegro units and like you said there was one with and without the turntable. I got the latter it would appear.

Good thing too because the cheap BSR turntable makes it look dated.

 

[doity]

Well I got the Zenith working. First I had to figure out how to open it up and that was no small task. The top does not come off, but instead you have to unscrew the back panel where all of the inputs and vents are and then you have to turn it upside down and unscrew the hardware that holds the works drawer in place. Even then I could only pull the ‘drawer’ out only partially because of the connections in the back. Not sure how the service techs did it...maybe they had to unsolder the connections in the back as the chassis itself is solid or maybe the back panel folded inward to allow it to pull forward.

The hardest part was measuring for the belt as I could not find it anywhere even though I had both the model and chassis number. I used a string and tape measure to get the right size and the replacement works perfectly. The only odd thing is that when listening to a quad tape, the ‘Matrix’ button needs to be in or it sounds terrible. Without engaging it the music sounds flat and instruments are missing from the mix. Not sure if the Matrix button engages the 4 channel amp but it sure seems like that is the case. Probably done as a money saving move.

 

[Circular Vibes]

I am wondering if the tape deck is in fact 4 channel. Only a look at the head will tell. If there are two markings, it will be two channel and the matrix button will make two channel spread into four. If there are four markings, then you would seem to have some issue anywhere from the head and change mechanism to contacts and wiring somewhere.

 

[doity]

You can clearly see that there are 4 markings. My thought is that it was a money saving move so that instead of automatically switching to 4-channel when a quad tape was inserted, the only way to get quad was to manually select it. And then it was a one size fits all thing. The 4 channel sound is working just fine I can assure you.

 

[Circular Vibes]

OK, that is good. Do you see behind the screwdriver a reed switch at the top to align with the slot on quad8 carts? You may be right about manual switching but I think even cheap Panasonic cart players would be automatic. I could certainly be wrong. My RS-858DUS has a switch to allow 4 channel recording on non slotted blanks but I don't think my deck is fully manual 4 channel nor is there a matrix switch per se. That might be because it is a deck only though. Either way, as long as you enjoy it and it doesn't get hungry all is good!

 

[doity]

Well the 4 channel indicator comes on but for some reason the amp stays in 2-channel mode until you push the Matrix button. I think that it is some kind of ‘Hafler’ type of circuit but boosted extremely well. Even 2 channel sources sound good but you can tell that most of the music is up front. With a quad cart though it is discrete but with a lot of added punch. I wish I had the owners manual so I could confirm my suspicions.

 

[Circular Vibes]

I wonder if the 4 channel reed switch is slightly bent. If it doesn't make good contact it might act the way you describe. Model F712W, Model 169-471 are the schematics available from Sams Photofacts. It bothers me that you have to pay twice for the whole info. Originally they were in the same Photofact folder. If you have access to a local library, you might be able to view them online for free or print for the cost of photocopies. I seem to remember that Sams has library only free access. You will have to Google for that info. Otherwise a reference library in a large city may have paper copies or a local TV/Radio repair shop with old files.

 

[doity]

I think that I found a major reason for my issues with missing instruments in regular 4-channel mode without engaging the ‘Matrix’ switch. The 8 track deck sends it’s RCA cables out the back and can be disconnected if someone wanted to hook up a reel to reel or other 4 channel source.

I disconnected these when I fixed the belt but failed to map out which one goes back where and they are not color-coded. Is there an industry standard as far as which color corresponds to which channel? I have attached a picture and I have it close I think but still feel like something is off.


Thanks!

 

[Circular Vibes]

I don't see the picture. What are the colours? Usually red is front right, black or white is front left, and the rears, whatever the colours, the lighter colour will be left rear and the darker colour right rear.

 

[doity]

Sorry CV, the image I tried to upload was too large and I had to resize it. Should be there now.

 

[doity]

Well finally got the Zenith running and cleaned up and all is well. Thanks for all of the input from forum members. For future reference it takes a 11.5 inch large flat belt. Hopefully I can save someone some time if they happen to come across this thread on the interwebs. Here she is in her new home