I have a 1934 Wooden Airzone. I have had trouble with getting the reduction tuner to work. I took it to bits and cleaned the ball bearings etc.assembled it and it was worse.when it was cleaned! Was there rubber in it originally?. I am stumped. For now I just superglued the thing solid but can undo this if I knew how to make the beast work again.
Any ideas?

I would have to see what it is albeit one of the radio's passing through is an Airzone 612.

There are a couple of variants of these. I have never seen one with rubber in it.

Normally the balls sit in three holes 120 degrees apart and engage the driven shaft in a groove in it. The cap that sits over them and retains them is tapered. There is then some form of clamping, spring device to force this "sun wheel" onto the balls so that they drive it.

That may be where the problem is? Bentone (non melt) type grease would have been a better option than super glue.

I don't have anything dismantled in the service area currently, with one of those drives. Although I think I have a reconditioned set with one.

Marc

Thanks Marc for your reply. I did try a none melt grease on my first attempt. I actually took it apart twice resulting in one broken tag. There was no pressure spring insiide it which would certainly make sense to have something like that. It had 4 balls inside it. I remember pushing them through opposite holes.

I should have said it was an Airzone(1931) chassis 511. There was a thin springy washer sandwiched between the domed retaining plates, Maybe it lost a few bits with wear?
Martin

That reads like a spider type of arrangement. Unless its in reversed, then I would expect one of those pieces to be a Spring Steel plate that pushes the cone of the driven onto the balls to provide drive off of them.

I will keep an eye out for an exploded view of one

Marc

Check this site
http://jlkolb.cts.com/site/vernier.htm

Marc

Thanks Marc. I checked the site and followed a link to a Jackson Brothers Type 4511 which seems identical to the one in the old Airzone.
I note it is not intended to be serviced.
It seems pressure is brought to bear on the ball race by the cupping plates and the bent over tags. Sadly I have already lost one having opened it twice. Even with extreme care twice was one to many for one of the tags. I think I need to source a replacement. Dicko no longer stocks them which is a pity. Digital tuning has all but put paid to this market I guess.
I could driil out the edges and use bolts but I am not sure the trouble is warranted if I can get a replacement. Especially as it will be probably touchy to get just right.
Anyway it looks as if tension on the ball race is a definite. Use it seems made it too sloppy.
Thanks again for your help. The mystery has I think been solved by you.
Cheers
Martin.

Those tags are normally only tinplate. You can, after cleaning the metal, often solder on a new tag.

If the missing washer is a wave washer, which is essentially a spring, you may be able to procure one from an Indutrial bearing supplier.

These are often in the back of the shafts in electric motors and in electric hand drill s etc.

Marc

Yes, I have seen such washers and I need to have another look at it again. I can see soldering clamping tags would be a way to squeese the disks together.
I'll have another go at it after I've shifted the unfinished radios off my bench. Far too much stuff on my bench at the moment. Got to grab some more high voltage caps tomorrow and finish off two projects I'm on first. Then I'll get back to it again.
The set tunes easily without the reduction, but I'd like to get it back to as close as possible to the original design.

Thanks again, Marc
Martin

I know the story, I am trying to clear the bench but am held up with parts also

I have an 18 tube monster on it and a complete console among other things taking up benches & floor space. I have to make the console a power supply as it is battery.

I just re-stocked some HV caps & seem to have gotten rid of a few thousand in the last year or so.

Marc

Just bought two planetery reduction drives form the US. Decided to save time and cut to the chase. I will have to groove one to take the dial cord that drives the scale.
Got to get the rattle out of a Bell set after I clean it up a bit. Got two chassis to recap and check first. Also An HMV needs recapping too. I have some scratches to get out of a plastc case.. I tried silver polish with some success then a dremel with a buffing wheel with red oxide rouge. Trouble is the plastic gets hot and starte to melt in patches. Not sure of the solution as the scratches are quit deep. Any tips?

!8 tubes is daunting, Marc even if you have a cicuit diagram.
Martin

New drives should solve problems.

Rattle sounds interesting? As long as its not the cone of the speaker.

The problem with plastic & buffing, is heat. Some use car polish. The main ingredient of which is baking soda (Sodium bi-Carbonate) or fine emery, which scratches more finely. cold methods are better.

If the scratches are too deep, they are probably better left

I have among other things managed to sort out the HMV record player (Circa1961) a new thermistor, some paper caps and the coupling electrolytics had dried (its transistor)

It also needed to be made to run on a different Voltage as the 9V types it used, no longer exist.

The biggest pain with the monster is the fact that it has been recapped before and all of the tails etc. were left from the old components. The person who did it was not particularly diligent or committed as wrong parts are used and a couple ar missing.

A couple of broken disks are still available & coming from the States; handy as its a 1936 model

Ther are plate resistors in the IF cans, all should be 5K, all are not, all are different types, one is cooked. One cap in there is also wrong.

In the other battery set cooked parts due to wrong wiring. A 50K resistor was added to the plate of the 1K7 after it's 250K was wired elsewhere. I expected the 1K7 to be damaged & it is, according to the tester (short).

Fixing this sort of thing is what kills time as its double & triple work, addiing to the cost of repair.

Marc

I see you have the problem of fixing the faults generated by others. It is good to have the original values to go on. In these situations.

I fixed the rattle which turned out to be the dial pointer vibrating on the glass scale and as well the dial scale itself rattling due to dried out black gunk. I left the dial in situ and sqeezed blue tack between it and the frame with the flat of a screewdriver on each corner and bent back the pointer. The pointer had worked itts way up the dial cord which brought about the problem. All OK now. I used my griddip meter to fix the scale/pointer.

I tried 1200 grit emery on the plastic case with some success. What really made a difference was some furniture wax. It covered remarkable well.

I am looking sadly at a blown 6SQ7 in an AWA. 512M I have quite a few valves but this or its equivalent is not amongst them. I am reluctant to "Upgrade" the circuit with a later valve which I have as no longer as designed. Might have to try and buy another at an exhorbitant price.

Your old player was it push/pull OC71's in the finals? Protecting these early transistors from thermal runaway was par for the course and a pain. Get the polarity wrong and you don't get another chance.

Martin

OC72 (4)*a senior moment"

. Toothpaste worked well on the celluloid of an airzone dial winddow, but had to be very quick, Marc

Martin