Excellent photos STC830. Now we need photos from a very early model with a serial number less than 3000, anyone?

"Slight accident..."

I emailed in the order (file names) 225, 226, 230, 232, 258, backbar.
They were posted in the order 258, 232, 230, 225, 226, backbar.

It looks to me as if Outlook might reorder attached files. I have other occasions of images out of order (not here) and just assumed that I had made a mistake. Now I wonder.

Don't change the MTL, I think everything is plain enough. And the photo order is more logical as it has ended up, given that Garyoz's emphasis is on the circuitry, and the photos with the backbar are now together.

Yeah, I am not sure how it all works with cut and paste sometimes. I've at times performed the "copy" part of the function from left to right, grabbing numerous files and then watched them be uploaded to the web server in a completely different order. It could be decided by file size or some other unknown aspect.

Off the subject of comparative circuits, apart from the four machine screws attaching the chassis to the base of the cabinet, there are six wood screws and a panel pin that attach the top of the cabinet to the base. I assumed that these were to preventing the top from parting company from the base and chassis if the radio was lifted by the cabinet top, which is likely given that it was originally advertised as a portable radio.

But it is possible to remove the top of the cabinet from the base with the chassis attached to the base if the six wood screws are removed and the panel pin winkled out, which mine could be since it was protruding enough to get a grip on it with small pincers. My radio case separated easily, but if glue was also applied and is still hanging on separation may not occur.

This is perhaps a little less awkward a disassembly task than removing the four machine crews securing the chassis and sliding the chassis out, but the main advantage would be easing cabinet restoration by making the inside of the front of the radio more accessible and making possible separate finishing of the varnished top and painted base.

Photos uploaded to Post 34.

Thanks Brad.

What I didn't try to explain without the photos was the small triangular piece of wood (fillet) glued into the angle joining the base to the top of the cabinet, which can be seen in the photo of the back of the radio. The cut-out for the fillet can be seen in the photo of the front. This was the only sign of a glued joint joining the base to the top. Paint can be seen where it has penetrated between the base and the top after assembly.

In my case the fillet was already broken when I received the radio. The radio would have been glued with the typical cabinet making glues of the day which, while strong enough that in my case the fillet wood broke, dry brittle. This brittleness was used by cabinet makers to allow disassembly by scoring along glue joints with a sharp knife and breaking the joint with a sharp blow. So if you are game given the radio's age, or have cabinet making experience this fillet should not stop disassembly of the cabinet.

Excellent photos does it have the change over switch?
Any more low serial number radios out there, please?

Yes, it does have, but the wiring for it and the extension speaker change-over switch has been removed. The switch is visible in the top left hand corner of the first photo in post #26.

If the mice have eaten your back board label here is a replica you can cut out and use.

Astor Mickey Mouse OZ Backboard

Thanks, but the backboard is OK.
The ARTS&P is missing though. If there were enough radios with ARTS&Ps and with serial numbers near 7522 would see if I could guess at the number for the ARST&P of my radio. Could then maybe set about making a replica using some sort of thin light blue plastic sheet.

Document uploaded to Post 39.

The ARTS&P should be white plastic for 1934, blue sticker for 1935.
See;

https://www.radiomuseum.org/dsp_hersteller_detail.cfm?company_id=18761

I am restoring a very early Astor Mickey OZ serial number 211. The schematic is not as per examples on internet or the HRSA supplement.
Obvious differences are:

1) filaments all in series connected to 68V AC winding on transformer.
2) the two diodes on the 25Z5 are in parallel making a HALF WAVE rectifier. There is no centre tapped high voltage winding.
3) it has the extra 620 ohm resistor in series with speaker field winding, minnie mouse speaker switch etc.
4) no asbestos heat shield above the 43 so slight heat damage cracks on case.
5) did have asbestos shield between volume control and transformer.

I have not checked all component values but putting in 24μF main filter caps I have no perceptible hum. and receiver is quite sensitive and working OK. Just made replacement metal cover over death power socket and internally clamped cloth mains cable.

So its pretty much the USA AC DC version with basic transformer addition as expected.

I have found these post very useful as I begin work on my Astor Oz, which I picked up last year at the HRSA Auction in Melbourne.

My Serial No. Is OZ 1172 has the valveline up 25Z5, 43,2B7, 2D7 AND 2A7. Unfortunately the output transformer has a large DC resistance 750K, which eventually dropped to 200K after putting a mega 250V across.

The 25Z5 is low emission, the 43 Is short and dead. The other valves are test good.

So I am looking for a 43 output valve is any one out there who can help me. Or suggest someone who can. As it 25V filament valve I am not aware of any direct replacement.

I'll see what I have got later today.
Note that 6F6 is an octal 42, so you could rebase a 6F6 with your dead 42's base.