If anyone has a better quality print of the circuit of the AORSM on CD HMV 779 it would be appreciated.
Set has been hacked a bit, but the machinery says the shield is connected to HV winding (1K) & that's not good.

Second is a request for circuit & info on a Astor 1930's Car Radio (stamped April 193_ :Pity stamping is incomplete).

1st RF 78; 1st IF 78; Pentagrid 6A7 (released Jan34) 2nd detector / 1st AF 6B7 (released Jan 34) Rectifier 84; 6V Vibrator type. Remote field coil spkr (stuffed). Remote controls & dial.

Have the diagram in AORSM 1938, designated HMV 779 B/Cast. The diagram is small (diag and component values half a page) but everything including component numbers and values is legible.

Will scan and send tonight.

STC380: Thanks. As said, one I have is hopeless especially when it has been got at and I just have to check everything, despite the transformer being in trouble.

I seem to be having a run on sets that have been messed up by DIY experts, this is the second from the same source, even that it was not the DIY new owner that was responsible for all of it.

I have to take the blame for one Astor I bought for a collector about a fortnight ago. Astor seemed to use the worst grades of rubber, and between it & a hacker, it took a week of spare moments to rewire it & sort it out. Even the IFT's & mains transformers were included.

The point here: Its fine to whinge about the situation, but only action & methodology will fix it, albeit that it will not happen in five minutes. These days with kids, its to easy to replace, or seek instant gratification.

Marc

The circuit is also in my Vol 3, 1939 and the circuit is quite clear. Between STC's page and this one, you should be OK. Emailed to your inbox.
Harold

1930's Astor car radios with that valve line-up including a 41 output are as follows:

220/DA, 6 & 12 volt. 1935 to 1937.

6376/EE, 6 volt; 6376F/FD, 6 volt; 12376/FB, 12 volt. 1936 to 1938.

6376S/ED, 6 & 12 volt. 1936 to 1938.

IF for all models is 173kHz.

My mistake it was volume 3. If there is anything not legible in Gandhn's copy, let us know and I'll scan mine.

The paper in the 1939 number is good quality and hasn't deteriorated. One other I have (1937) is not so good and the pages are literally falling apart.

It's interesting to see the internals of a car radio of that vintage. It's not something that I would ordinarily come across or seek out.

Watch that condenser at the top right. It'll contain PCBs.

A well built machine by all accounts. Almost military spec.

With thanks, I have now have a readable HMV circuit & can sort the mess while it is decided what to do about the transformer.

The Astor mentioned got taken home, so that's one less in the line.

I did not seek this radio, In the Vintage Car Club here, they know I fix radio's, so it quickly found me. Some newer ones are horrors.

If photo's of the pan of the Car radio are wanted, it can be done. I worked in Chemistry & that cap is not alone in containing PCB's: Some paper types have it as well, e.g. The grey metal clad ones.

Some paper is acidic & you can often smell the Acetic Acid (Vinegar) I have a few books like that. I do make a point of putting Sodium Bi Carb in porous sachets in the containers of books when they have to be stored water proof & vermin proof and in a couple of instruments here that create acid internally.

Marc

Just noticed that there is a voltage table on the two pages over - did you get that Gandhn?

If photo's of the pan of the Car radio are wanted, it can be done.

I think they would be interesting to add to the first post for the record ... although I gather the exact model is still unresolved?

The voltage table for the HMV is readable and is needed to repair the transformer after it is stripped down. albeit I have other ways of supplying it in the meantime to get it mobile.

Just noticed that there is a voltage table on the two pages over - did you get that Gandhn?

I missed that, but Marc's table is readable (post above), so all is good.
Harold

I have pretty much all I need, can't do much about the owner. The other thing that is not clear is the boards albeit I can work around them. I note the 6V6 is as I keep saying, the grid resistors have failed.

Interesting that the missing back bias resistor is at the opposite end of the set to the rectifier & speaker plug and then wires for the CT and an electrolytic run all the way back. Some designs do leave one guessing? I have had to make small mods to a couple of sets this year, for design faults causing feedback, or instability.

Car radio is not in work just yet, need to have a discussion with its owner about some mechanical issues.

Marc