[Antipodal]

Hi everyone, 
I have come across the remains of a car radio of considerable vintage. The valve lineup is OZ4 41 85 58 57. The components suggest it is American. There is a sticker on the chassis which has been partly rubbed off but the remaining letters are  " ....LAN BROS. " Does anyone know if Gilfillan Brothers  ever made car radios? Or were there any other U.S. manufacturers  with Brothers in their title? And the valve lineup suggests an odd mix of filament voltage for a 6 volt car radio but the tube numbers are stamped into the tube sockets and the sockets are all original riveted in .Any help in unravelling this mystery appreciated. 
Thanks

[Arran]

There were a few books put out back in the day to identify various makes and models of radio by the layout of the tube sockets, and the types. I think I may have a reprint of one somewhere, but there used to be a web page where you could do this.Regards An alternative may be to try looking up Gilfillan Brothers sets on Nostalgia Air, Gilfillan was an RCA licensee so they made a lot of their money renting out parts of their plant to smaller manufacturers who wanted to use their license. The tube/valve lineup is a bit strange in that an 0Z4 is an octal based cold cathode, gas rectifier, all the others have the old style bases.
Regards
Arran

[Arran]

Hello Again;
  I had a look through the Rider Manuals I have from 1935 to 1942 and whilst Gilfillan did manufacture some car radios, and did use some 2.5 volt AC tubes in some of their AC models, I couldn't find a single car radio that used 2.5 volt tubes, let alone a mix of 2.5 volt and 6.3 volt tubes, nor a mix of those and a 0Z4 cold cathode gas rectifier tube. All seemed to use 6.3 volt tubes, and maybe an #84 rectifier (basically a older six pin ancestor of the 6X5) I did not look at their post war sets however. I also looked in a reprint of an RCA book put out a set index based on tube/valve socket layouts, there was even less in it then the Riders books under Gilfillan, maybe six sets in all, and only one car radio. If you could post a photo or two that might help, assuming the ###an Bros was not the manufacturer, and not a dealer or importer.
Regards
Arran

[Antipodal]

Thanks Arran , You have certainly put in the work. I will try to get a few pictures up of this set. The odd mix of 2.5 and 6.3 volt tubes was the centre of much discussion at our  vintage radio group here.All the best

[Arran]

No trouble at all, I had to look up what I may have had on a U.S made General Electric model (as opposed to Canadian General Electric) and thought I would look up Gilfillan Brothers at the same time since the Riders listing are in alphabetical order anyhow. I have a pair of Gilfillan sets but they are both your typical post war AC/DC radios, basically with the same circuit, but with different dials and cabinets. That weird tube lineup made me curious, I would guess that the 2.5 volt tubes are in series, but the 6.3 volt ones are not, sometimes radio manufacturers would cobble things like that together to get around parts shortages, or use up surplus parts, Philco was notorious for doing things like this both in the U.S and Canada, they even built a few sets around surplus car radios after the U.S halted car production, one using a Ford radio, the other a MoPar (Chrysler) car radio.
Regards
Arran

[MrFixr55]

I agree that it is likely a Franken radio from the manufacturer who likely got a deal on the 57, 58 and 85 tubes. The 85 is a 6.3V duo-diode triode det /1st AF tube. Strange that they are using it instead of a 75 or a 6Q7 as the 85 requires substantial (-10 to -20V) negative grid bias where the 75, 6Q7 or 6SQ7 usually have no added bias, therefore they likely got a deal on them also. The 58 is likely the IF instead of a 78 or 6K7 and the 57 is an "autodyne" convertor (1st detector) instead of the 77 or the better and more stable 6A7 or 6A8 pentagrid convertor. For these 2 2.5V 1A tubes, there is likely a dropping resistor and these tube filaments in series. Using a 0Z4 saves some filament current. According to Radiomuseum, the 0Z4 was released in 1935 and first used in 1936., so this is likely a 1936 model year radio.

The use of autodyne convertors as opposed to pentagrid convertors in car radios of the mid 30s was not uncommon. In fact, Delco used an autodyne 1st detector, using a 6C6 in Cadillac radios for the 1935 model year and a 6J7 for the 1936 model year.