zenith: Zenith 10S492: Restoration

I'm new to this forum and just purchased a 10s492 that needs some serious restoration. I want to show my progress and what needs to be done but I have no idea where it would go in the forum.

This is my first ever restoration and am in the dark on alot of it so I am really going to need all the help and advice I can get



I'd appreciate the help so I can start uploading my images of the restoration as soon as possible.

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Sure! Here is the present condition. I'll upload more as time goes on. Presently the chassis is out and awaiting restoration. the photo finish on the center column between the doors is too far gone for restoration.

I see the 492 in the database has been refinished, the back is missing where I have one, a different phonograph player has been installed, and the cabinet is darker that what its supposed to be. 

I want to restore the cabinet to factory new condition as possible yet keep some of its character (little nicks, etc.)

This is my first ever restoration project so I know I'm going to need a lot of help with this. 

unfortunatly there are are no really good pictures of this model cabinet or chassis to use for reference.

• SANY0174 (47 KB)
• Label1 (59 KB)
• Close up of speaker (56 KB)
• Close up of cabinet and damage2 (55 KB)
• Speaker and antennas (56 KB)
• SANY0189 (57 KB)
• SANY0190 (56 KB)
• SANY0186 (65 KB)
• SANY0177 (76 KB)
• as is (34 KB)
• SANY0193 (51 KB)
• SANY0190 (56 KB)
• SANY0189 (57 KB)
• rear of cabinet1 (56 KB)

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Paul,

Thanks for posting the pictures.  I'll let others comment on the restoration of the cabinet.  I'll give you some pointers on the radio and phonograph.

The radio will definitely need its electrolytic and paper capacitors replaced.  Are you familiar with identifying these two types of capacitors, and do you know about polarity of electrolytic capacitors?  (Just checking to see what you may already know; if not, I will be happy to explain).

To find sources for capacitors, check the supplier list.

Also check under the chassis for any signs of damage or burned components.  It is not recommended to plug it in until you have at least replaced the electrolytic capacitors.  Once you've done that you can test it briefly to see where it stands.

The volume control may need to be cleaned, as well as switch contacts on the band switch, tone control switches, and preset station switches.  You may want to get a can of De-Oxit contact cleaner spray for this purpose.

Tubes are often still OK, since tubes do not deteriorate with age -- only with usage.  For now, don't order any tubes, and assume they're good until proven otherwise.  One exception is likely to be the eye tube.  They have such a short life that they are often bad.  Since the radio works fine with a dim or dark eye tube, most users in the old days didn't bother to replace them when they went bad.

For the phonograph, most likely the pickup cartridge will be bad, and the rubber tire on the idler wheel will need to be rebuilt.  The changer mechanism will likely need to be relubricated (and any solidified old grease removed).  The cartridge can be rebuilt by West-Tech Services, and the idler can be rebuilt by West-Tech, VM Audio, or Ed Crockett's Vintage Electronics.  See the supplier list to contact any of these.

If you have more questions before you start, please ask.  Otherwise, you can get started with some of these steps, and check back in here as the work progresses and new questions come up.

Best of luck with your restoration!

Tom

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the cans are the electrolytic and the ones that look like paper tubes are the paper capacitors, Right? If the Eye Tube is indeed bad, where whould I get a replacement?

80% of the wiring has the insulation falling off so I'm going to replace all of it. What wire is the closest to what the factory installed and what colors? the original wires are so bad they all look black. My goal is to make it as close as I can to what it looked like when it was brand new. like if I have to strip and refinish the cabinet, what would the correct shade be?  

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Paul,

The supplier list linked above is where to find basically everything.  There are 10 or so companies that sell tubes, so you can comparison shop a bit to see which ones can supply the eye tube you need and who has the best price and shipping cost.

It's a little unusual for the wires to turn black, unless that's what color they were originally.  Often I see the original colors are significantly faded, but that tends to turn them lighter, not darker.  It may be the case the your wires were actually black or brown.

If the original wires were cloth-covered, you can find a few sources for that on the suppliers list.  Otherwise, if the original insulation was rubber (that is probably what you have, since you describe it as distintegrating and in need of replacement) then modern vinyl insulated wire is a good match.  I prefer to use wire salvaged from old TVs and radios, since that is a bit closer to the original, but that only works if you have been in the hobby a while and have salvaged parts from junker sets.

The can type capacitors are indeed electrolytic, with a common negative terminal on the can.  Tubular cardboard capacitors are usually paper capacitors, except for those with a capacitance greater than 1 uF.  Those are also electrolytic and will have a polarity marked on them.  Your radio may or may not have any of those.

I'll leave the cabinet refinishing questions to others.

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Dear Paul
I wish you success in your project. By the way: When you click a tube, you get all details about it - and also some tube supplyers with their prices.

Your photos of the set are nice, but could be size 933 pixels wide (up to 1400 hight).

Most essential would be good pictures from the wiring side of the chassis - untouched - on the model page !

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Do You want the underside of the Chassis?

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Yes, a picture of the underside of the chassis prior to restoration is a nice way to document the original look of the wiring under the chassis.  Often people have radios that have been serviced or modified over the years, and they would like to know what an original looks like for more accurate restoration.

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Here are some pics of the underside of the Chassis. 

• Underside 1 (70 KB)
• recent repair (46 KB)
• underside 2 (66 KB)
• underside 3 (69 KB)
• underside 4 (67 KB)

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While Cleaning up the chassis and the tubes I found that the last time the set was serviced was in 1949 according to the label on the tubes.

The Plug Going into the back doesn't look to good and I don't know How I'm going to fix that....

• Date of last Service (38 KB)
• frayed wires (49 KB)

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Hi Paul,

You can easily repair those frayed wires going into that plug.  The wires can be individually unsoldered from the plub by heating each pin from the other end with a soldering iron.  When the solder melts, just slide the wire out the back.

Then you can cut off the frayed end, restrip the insulation in a nice clean manner, reinsert the wire into the pin, and resolder.

Before reinserting the wire into the pin, you may want to remove the old solder in the pin by heating up the pin and either blowing the solder out, or slapping the plug against a table top to pound the solder out.  Otherwise you can just heat up the pin while reinserting the wire.

Tom

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Been busy for the past couple days so I'd quick do a follow up:

So Far it seems that all the wiring underneath is fabric covered except for the eye tube. that's stranded what I assume is rubber that the insulating is falling off.
I will probably replace it with fabric to match the rest of the wiring

Cleaned out the cobwebs and dust. Now I've got to sort out what exactly what I need. I want to add and Mp3 jack input so I can Play OTR.

Now on the back of the chassis is a switch for "television" and Radio.

I have been curious in what this was for. I wondered if I could hook it up to this but don't know yet. I'm going to need some guidence on that when I get to it. I can't install it to the phono output because the 492 has one built in.

first off is the eye tube:

The wires are too far gone so I'm just going to snip them. this will help in the long run when I add the new wires. the new ones will be more appropriate fabric covered.

Next the tubes. I'm taking off each tube and noting its location on a picture I've taken. as easy as adding a label to it on photoshop.

Next, I'm wrapping them in paper towel and marking them with my trusty sharpie for easy identification:

and get packed away in a box I found in our cottage up north:

• SANY0176 (40 KB)

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Well I got the list of Capacitors I need and I'm going send the order to Just radios monday. I still need expert opinion on what is the best fabric covered wire to get to be as close as Possible to the original wire.

But before I do I need to figure out one part:

the other thing is that it looks like the ecap is different that what the schematic reads. Now according to the schematic, its part no. 22-934: two 20mfd ecaps: one at 450v and the other at 350.

This on the other hand shows something much different.

You can see the state of the auto tuner wires in that shot.

It lists three capacitors! All three are 20MFD and the first two are rated at 450V but the third is listed at what I believe is just 25V. What is going on??

Well, looking underneath I can see the insulation is falling off the wires going to the IF can so that comes off next.

I pulled the guts out to see the condition of the coils and they look pretty good.

any shoutouts are welcome.

I'll carefully pack this away while I wait on the wires. the can, however, has a date with some neverdull wadding.....

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Hi Paul,

You can use the Television input for your MP3 player.  Just flip the switch to "Television" and the pair of connections on the back are your audio input from the MP3 player.  What is wired to the TV input right now?  Your picture shows a yellow wire going into one of the input connections for the TV.

Since you have the closest view of the wire in your set, you're the person best equipped to decide which replacement wire to buy.  You can get wire from Sundial Wire, Just Radios, and probably several others sources on the supplier list linked above.  Take some time to try many of those links and find out what the various companies have.

Your electrolytic can capacitor is newer than the rest of the radio, so it was replaced at some point.  Often it is not easy to find an exact replacement for a multisection can cap, so it was and still is common to replace with something suitably similar.  For example, replacing the 350 V section in the original with a 450 V section in a new cap is perfectly acceptable (always OK to replace a cap with another one having higher voltage rating).  As far as the third section in that cap goes, you might find it is not connected to anything; it was simply an extra section not needed in this radio.  If it is connected, trace the wire and tell us what it is connected to and we'll interpret what was done and why.

If you can't find a suitable multisection can cap to replace that one with (many of us wouldn't even bother to try finding one), you have two choices:

1.  Unhook the can, but leave it in place for cosmetic reasons, and wire individual caps under the chassis to replace the dual section can.

2.  "Restuff" the can by removing its innards and hide new single section caps inside the can, wired to the original terminals on the can.  Some people like to do this; I usually don't bother and do #1.

Best regards,

Tom

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The 492 has a built in record player so that might be what the yellow wire is for.

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Paul,

In the same photo that shows the yellow wire, I see an RCA jack to the left.  I would have assumed that's the phono input.  However, checking the schematic, I don't see any indication of that phono jack.

If you want to have three inputs -- radio, phono, and MP3 player, and the only input selection switch is the current two-position TV-radio switch (which may be currently used as a phono-radio switch), then you will need to add one more switch.

What I find surprising, however, is the following:  If this radio had a factory installed phonograph, I can't imagine that the means of selecting the phono input would have been to use a switch labled "radio-TV" on the back of the cabinet.  I would have expected the bandswitch to have an extra position for phono.  Can you check whether this radio has an extra position on the bandswitch, and whether that is wired to the RCA jack on the back (where I would normally have expected the phono input to be)?

Tom

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Oops, I posted the wrong pic of the chassis back. here is mine:

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Paul,

Indeed I wondered about that, having noticed the picture of "your" chassis seemed to be a picture from the model page here, which is not your chassis!

If your radio had a factor installed phonograph, where was the audio from the turntable fed into the chassis?  What kind of connector is on the end of the phonograph audio cable, and where did it plug in?  And is there an extra position on the band switch, or just the same number of positions as bands on the tuning dial?

Tom

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Here is the cord for the phono:

and how its connected:

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Hi Paul,

That's the phono motor power cable.  There are always two cables from a phonograph:  1)  the motor power cable, and 2) the audio cable connecting to the pickup cartridge.

Can you find the audio cable?

Tom

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Here is a pic of the underside:

and a picture of the back of the unit before restoration:

and a close up of the speaker hookup:

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Although I don't get the impression you even tried to figure out what cable goes to the turntable pickup cartridge, I think I can tell from your pictures that it is the big sheilded cable hanging in a loop near the speaker.

And you didn't check whether there is an extra position on the bandswitch, but I suspect there is.

If the above is true, you can use the TV input for your MP3 player with no further modifications.  The phonograph does not use the TV input.

Tom

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I'm working in stages. Radio, Phonograph, cabinet to keep from getting overwhelmed.

the cabinet and chassis are in two different locations right now. I wasn't able to get to it today.

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