Astor two-valve radio.

[Alan Merritt]

Hello

Found this two valve radio today - I've never had one this thrifty with the valves! Cabinet has been sprayed, and partially stripped back.

I've never seen such a tube line-up, either: They're both Made in USA , and from the rear, the left hand one 12B8 GT Hygrade and the right 32L7 GT National Union Electron Tube, it's possibly a US design, and components are Australian made.

The knobs were very solidly glued onto
the shafts, and prising them off meant the cabinet and chassis separated. Maybe live chassis? No ratings on capacitor can.

Very long ?aerial wire attached is original The plug is clearly for mains 240v, and the speaker has an output transformer, otherwise it's a mystery to me as to it's origins.

A few photos speak volumes, look forward to your comments and advice.

Cheers from chilly South Australia!

[Reece]

Rather odd design. I was not familiar with these tube/valve numbers. Looked them up: the 12B8 is a triode/pentode, and the 32L7 is a rectifier/beam power output. So you have the equivalent of a four valve/tube set. The heaters add up to 44 volts, to run from a 240 volt power line, so they had to add a transformer, which is not cheap. Then they added a dial light, which is usually left off a cheap radio, so I'm sort of getting mixed signals about where the money was going in designing/building this set! It has a field coil speaker so that must serve as the power supply choke: wow. There are cheaper ways to build a low cost radio but this doesn't seem to be the way? They could have added another tube and an IF transformer and made it into a superhet for just a couple of dollars more! There were some tiny two-tube US sets in the late '30's but I'm not familiar with them. They I believe used resistance line cords to drop the 120 volts to what the heaters wanted, something that only gun-totin' US cowboys would tolerate, and would not fly in the land of high-voltage Oz!

Keep us informed on what you find in this interesting set!

[Sandy G]

I have both 2 & 3 tube Arvin sets from the Thirties. Cute l'il guys, the DO pick up stations, but aren't exactly 1st rate BCB DXing machines...

[jr_tech]

Alan Merritt... Nice Find !

Sandy G... I need to learn more about these simple 2 & 3 tube sets... Was the case design similar to the Arvin on the right?


2 Metal Arvin Case Styles

But likely using a "pointer" style tuning knob?
jr

[Sandy G]

Yeah, the 2 & 3 tube babies kinda look like little bread loaves, like the guy w/the maroon knobs..

[Alan Merritt]

Of the underside.

Thanks for the replies so far, although a lot of what Reece said baffles me!

The valves seem pretty rare, my local net searches have not been helpful.

I will do the usual - replace caps and test resistors. If OK, then clean switches, etc then a start with a lightglobe as ballast.

Any hints with circuit diagrams? The cap ratings are difficult to detect.

Cheers, Alan

[Alan Merritt]

Had trouble attaching..

[old_coot88]

Hah. Interesting little bugger. Looks like it is a superhet judging by the tuning condenser having one section smaller than the other, and what might be a single, unshielded IF xfmr mounted directly below the tuning cap, under the chassis. Bill(oc)

[Reece]

Alan, I don't wish to be baffling! What in my post do I need to explain further? Be glad to.

[Alan Merritt]

on second reading, it makes a lot more sense, Reece.

However it still applies somewhat to "make it into a superhet ...for a few dollars more.." .."field coil speaker as power supply choke: wow.." it seems the dial light is an integral part of the circuitry...

I as as a self-taught fixer my plan here was to do the usual re cap etc, as in my previous post.

Will keep you posted.

[Reece]

What I was getting at is that the el cheapo two or three tube sets made in USA were really made on the cheap with as few parts as possible, no dial light, no "airplane type" dial but the tuning condensor with the knob directly on its shaft, no mains transformer, the heaters in series, and the extra voltage drop to the heaters handled by a big resistor on chassis, or a resistance-type line cord, which had a thin nichrome resistor wire wound around an (gasp!) asbestos core. The cord would get warm in use and the user was warned to leave it extended so that it would dissipate the heat, but who reads warnings? These things earned the moniker "curtain burners!" Some of these sets got put in metal cabinets besides increasing their potential (pun) to be little shockers, all of which seems pretty far-fetched today, but we pioneers were a tougher lot then. I know Aussies were, too, but dealing with dropping 240 volts through a line cord would have been another story, thus the mains transformer in your set. Do you know of any Austrailian sets that don't have a mains transformer, but are connected directly to the line? That may have been prohibited by some code.