I picked up what I thought was a Stromberg Carlson model 4A17 a 4 valve chassis.
But what I got was unlabelled no S/N 5 valve chassis. The valves installed were , EK2, 6G8G, 6SJ7,6V6G and 6X5G.

I have looked on the HRSA Radio Model list , Radiomuseum and could find no radio with this valve line up.
I was able to get the radio working after replacing the caps and some resistors as well as dealing with so poor soldering joints.

The key questions here for this knowledgeable group is
1. Has anyone seen this valve line up and can confirm is this is in fact a Stromberg Carlson Chassis?

2. The reason I suspect it is connected with Stromberg Carlson, it was in the 4A17 cabinet but it also has the unique guiding slots that fit in the moulded Bakelite tags that correctly position the chassis in this cabinet.

3. The Chassis has no markings at all not even a serial number that I could find. The IF coils are clearly marked Radio Corpration P/L this might be a clue.

5 The real intersting fact is that the layout of this chassis is something I had not seen in an Australian Mantel Radio before the Power transformer sits in the middle of the chassis. I can send some pictures to Brad if you are interested and you thing you can help me find out any information at all about this chassis.

I have sent some pictures to Brad, also the IF coils are label RCS Radio Pty Ltd, not sure if that is the same as Radio Corpration?

Radio Corporation sounds like RCA, an American firm. RCS was (I'm pretty sure) local to Sydney. I'd say they are the ones that made your IF transformers.

RCS Radio was a quite long lived local company based in Sydney, at a few different locations throughout its existence. It started in a shop opposite Victoria Park near The University of Sydney and shifted from there to Canterbury Road, Canterbury and when the company was wound up about ten years ago it was located at Chester Hill.

RCS started out making radio parts for kit radios and the smaller manufacturers and in recent decades were the provider of printed circuit boards for kits described in Silicon Chip, Electronics Today and Electronics Australia magazines.

Radio Corporation was a bigger company, which made Astor radios in Melbourne, and later a few other brands.

In the late 30s Stromberg Carlson imported many parts (including those unusual IFTs with the adjustments on the side) from the US.

This radio looks like it was made during WW2 (when imports became difficult) so they used locally-sourced IFTs from RCS.

Thanks for loading the pictures Brad.

The mystery around this radio, which I am starting to believe is home made/kit, is if you look at the third picture,there is a special positioning lug on each side as I mentioned in point 2 of my initial post. This lug slide over the tabs on each side of the specific cabinet of the SC model 4A17. I have not been able to find a 5 valve version of a chassis for the 4A17 anywhere.

As also note in my initial post point 5 the positioning of the power transformer is quite unique to me, but keen to hear is anyone reading this post has seen something similar. We usually see the power transformer on the far side of the chassis. Are there any other example of a Australian chassis with the power transformer in this position?

Also the electrodynamic speaker with the Output Transformer makes TG-1 is exactly the same one used in the AWA Bakelite R31 Empire State Radio which I own, though mine is painted that AWA blue.

I love a mystery but any information or ideas on this chassis would be great.
Thank you for clarifying the RCS history and Ian's suggestion the this could have been made during WW2 has merit but love to know who made it and why it suited to this particular Stromberg Carlson Cabinet.

My late mum had (and I still have) an STC mantle radio of the same vintage.

It is a 4 valve set but the chassis number stenciled on it calls up a 5 valve.
She acquired it during WW2 when she was working for an advertising agency.
She was required to log the radio advert playouts to make sure they were getting their money's worth.
It was obtained for her at a time when you couldn't buy a new radio but STC were one of the agency's clients.
She was told that they put the few civilian radios they made together from parts that they had.

It has an electrodynamic speaker too. Cobalt for magnets was kept for war purposes.

The speaker in your Stromberg Carlson would be a Jensen, made by MSP which was a division of AWA.

At least this radio has good quality valve sockets, better than those common brown wafer ones.

Hi Ian,
What model was the STC your mother had, or was it not designated a model number.

I think you are right I am guessing this was made of what ever parts that could be found during the war and they made it to suit the Stromberg Carlson, Cabinet model 4A17.
The speaker is definitely found in AWA radios of the late 30s, did not know they were made by MSP, they have a strange metal cone centring configuration which sometimes causes a terrible rattle.

As there is no visible serial number, Stromberg Carlson,though they did use stencil type labelling even for the serial number so it might have been all rubbed off or it was not a production model at all.

Any comments at all about the positioning of the power transformer, or is this more common than I thought, I am a little oppressed with layout and why it was done this way, it also could be a matter of why not?

Your right Robbbert those wafer sockets are for causing intermittent problems that are time consuming to identify.

Cheers George

Jensen speakers, especially the American ones tended to have a deeper cone than all others. There are two types of "spider". There is a three legged spiral on the inside of the cone, alternate is a full convoluted circular ring, under the cone.

If it rattles I normally use a function generator to find the frequency at which it rattles. This can be from a loose cone, or "poling" due to the cone being ripped, warped. or the voice coil hitting the centre pole through mis alignment of the spider, or any of the previous.

Plus foreign objects in it

Marc

If it's of any help, I recently restored a 1940 AWA Fisk Radiola "egg crate" model. It started life as a 4 valve battery-powered set (86Z I suspect), but was modified in 1964 to be a 5 valve 240V set. It has the power transformer mounted centrally and the chassis also has the same retaining lugs as yours.

Hi Jacksprat, sorry I did not respond earlier, have been travelling.

That is interesting but makes sense for the transformer to be mounted where the original 'vibrator' box would have been mounted. So it does raise the possibility that mine could have been a battery set, though if it was modified it was well before 1964, possibly even in the factory.
The metal chassis box might have been intended for a battery set, thus the central placement of the power transformer.

No, they used the same chassis for two or more different models, Standard practice.

For info I have sent Brad a photo of a HMV 847. This is a 6V battery vibrator set converted to mains. Speaker is not original.

If it was a battery set it is very likely that it may still have battery valves, as is the case with the HMV. Eg.1K7, 1L5. Goat shield added to stop the 1K7 oscillating.

Photo uploaded to Post 14.