Hi

I have a David Jones 30-33 era radio that I am about to restore to working order. Does anyone know who produced radios for DJs in that period and where I might obtain a circuit diagram. Valves are, 35 x 2, 24A X 1, 80 X 1, output missing and unknown and 3 are shielded by a horseshoe shaped shield that slots into the chassis . The dial has numbers and no station markings. I think the speaker is a Magavox.

Regards

Greg W

David Jones' house brand was St James (named for the St James precinct where their Elizabeth St store still stands). Many (all?) were made by A.W. Jackson P/L, though I don't know what year the St James brand came into use for radios, but I think it was later than the 1930s.

Yours is likely a TRF set. The missing valve in your line up may be a 47.

Thanks GTC. I have a St James TV from the late 50s but have not seen early 30s radios with this brand. The radio in question has DJ pressed into the transformer cover and on the dial escutcheon.

Looking around, it could be a Vox Humana manufactured by T.F. Stewart & Co. Ltd, Sydney, circa 1932.

Photos uploaded.

Interesting. Looks like it's already been restored at some time.

I wonder if one of those controls does regeneration?

I'm intrigued by the stamped transformer casing. I would not have thought the manufacturer would have gone to that level of trouble to brand a set. Dials, yes.

I looked up the trademarks database and found that David Jones first registered "St James" on 26 May 1927 for "Goods of precious metals (including Britannia metal) and jewellery and imitations of such goods".

DJs registered St James for "Vacuum cleaners and carpet sweepers; radio receivers and valves therefor" on 10 Sep 1937.

A bit of guesswork here. That transformer is not original ( signs of another transformer ) . Possibly like my EMMCO Troubador it may have started out as 2 volt filements and been converted to 6 volt. The rectifier socket doesnt look original either. The I.F cans are identical to my EMMCO as well.
Im guessing EMMCO made the chassis.
The cover on the new Transformer may be from the original.

Before, the site chucked wobbly. I was going to point out that the early EMMCO AC4 has the same valves listed. I have only worked on one of their sets it had been seriously monkeyed with and EMMCO circuits are like hens teeth.

I ended up reverse engineering it and it appeared in Silicon Chip, or something like that. I sent Kevin Chant the circuit with appropriate warning on it as to how it had been derived. I also had a series 59 STC Chassis; Neither I or HRSA could find a circuit so it got reverse engineered, a couple of mods made and listed why on the new circuit, also sent to HRSA & Kevin as that may help someone else.

EMMCO would have made most of the parts for it, including the transformer. That is an advanced "Padderless" tuning gang and nothing like the common Stromberg-Carlson & AWA types used by nearly everybody.

The spec I have for it seem to have newer valves like #58. However, a change in valves was never uncommon as many just changed filaments & bases & the circuit changed little, or nothing. as it was the same valve electrically (E.g. #80 /5Y3 ; 6A7 / 6A8; 6D6 / 6U7) It is very likely that if the set was made for an exclusive more "exclusive" up-market end use, It would be built differently than the one for the commoners.

As with the EMMCO I had and several others, reverse engineering is time consuming, but allows one to work out, like the EMMCO here, work out what the Monkey has wired up wrongly. EMMCO also used bottom trimmers on some IF Transformers.

For those who dare I have explained my way of reverse engineering. I will not leave the original wire in a failed tube resistor. That gold wrapped cap looks European as there are some here.

Marc

I believe the transformer is original........the extra mounting holes in the picture are for an outer transformer casing which I had not put back on. The rectifier socket looks to be identical to all other sockets in the radio so maybe the picture is a little distorted. Carl, do you have a circuit for your EMMCO? In response to other comments, one control is obviously volume/on/off. The other is connected to the IF area so it could be regen...... I don't know enough to say with any certainty. It did have some repairs made about 13 years ago by a local expert but I never got around to putting all the bits back or hooking it up to the speaker, so I would like to check it over and fit the correct output valve which I have misplaced along with the knobs.

Greg Williams
The closest schematic for my EMMCO is on the Kevin Chant site. What makes me think the rectifier socket isnt original is that you would usually find a 80 rectifier ( four pin ) in that position. Possibly all sockets replaced as a upgrade to the 6 volt filements. Having a on off switch also tells me its been modified as ( I could be very wrong ) because most AC operated sets at that point in time were run off light sockets (houses back then rarely had many AC wall sockets) which are not polarised and the only safe way to make sure you do not end up with a hot chassis was to use the light switch to turn them on or off. Other high end manufacturers started using double pole switches.
It looks like who ever worked on this was quite neat.
Oh and I didnt see Marcs reply. The EMMCO schematic I refered to on Kevins site is Marcs efforts.
Another observation is the existing electrolytic cans. Have they been restuffed with new Caps? There are no new ones underneath! I believe the capacitor cans may be out of a newer set ( 1950s) and restuffed as these cans did not appear in this time frame.
Seems I was looking at the wrong socket on top. You have a 80 rectifier.

Another observation. The replacement potts! are they upto the current handling requirements? As I believe the originals would have been wire wound!
Greg I notice you are a Canberran. My email is open so why dont you arrange a visit maybe to look at the chassis or a cuppa and a chat.
Regards Carl

Thanks to all for your help in identifying the radio. Now that I have seen the circuit for the Emmco AC5 on Kevin Chant's site, all I have to do is check the caps, find the 47 and connect the speaker. The previous repairs were carried out by the late Ron Snashall, so I am very confident everything else is good to go. Will let you know how it goes.

Regards Greg

I might just have a 47 in my stash. I will look on the weekend!
So it's still a 2 volt filement!

Same as the ones listed #35 has 2.5V heater; #47 2.5V heater, grid bias -16.5 250V Anode and Screen Rl 7K, Wo = 2.7 Watts.

At the time the circuit was drawn it belonged to a collector (still has it) and all that we had confirmed was it was an EMMCO & found pictures of the chasses that could be bought without cabinet from Trackson Bros Qld. but really had no idea of which one it actually was.

I have photo's of it as it ended up in a Mag. The chassis is nothing like the one shown here. As noted; that one was hacked. It was reverse engineered as it was and not touched until such time as the new circuit was vetted by several in the Radio Club to ensure that it was correct on paper. Then, and only then, was that circuit transferred to the unit and wiring errors fixed.

In situations like this rushing into it will not succeed to the same extent as planning. It may (and did) take longer to attain a circuit, but the time lost one end, was saved at the other & nothing got damaged.

Marc