[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.

[Joe Rossi]

There is a Mission Bell model 19/19A that could be what you’re looking for, Riders vol 4. It has the tube line-up of: 0Z4, 58, 57, 41, and a Wunderlich tube. The Wunderlich tube is replaced with a Sylvania 29 (2.5v filament) or a Sylvania 69 (6.3v filament). I got this info from vacuumtubesinc.com under “Tube Tidbits”. Cheers,

[Antipodal]

Hi everyone, 
Special thanks to Joe Rossi for tracking down this obscure radio and thanks to others who took up the hunt as well.
I must apologise for sowing mis-information.  I identified the rectifier in my initial entry as an OZ4. It is in fact an 84.

But thanks to Joe it can finally be identified as a Mission Bell Model 19 or 19A car radio.I checked the i.f. frequency - sure enough it was correct.

Some interesting points arise with this set. 
First of all it has turned up here in N.Z.  
 Gilfillan radios sold well here in N.Z. I have been to a museum here in the South Island devoted to Gilfillan sets. 
Secondly ,yes, very odd mix of filament voltages for the valves with both 6.3 and 2.5 volt valves..The 2.5 volt valves are in series ,the chain ending with a half ohm wirewound resistor to earth.  I measured the voltage across the last 2.5 volt valve filament at 2.3 volts.  The wunderlich valve is replaced by an 85 and the socket wafer  is embossed 85 so  the set  may be a later example .I note that Gilfillan Bros address  was in Venice Blvd in Los Angeles and Mission Bell seems to have had their factory , or at least their address very close by which lends weight to the idea that Gilfillans rented out parts of their factory, although of course I have not been to this particular street or indeed to Los Angeles..

As found the set had had a rough time! Sundry wires hung off in all directions and there was no tuning head. The chassis had been butchered around the  tuning condenser and the aerial coil was not connected to anything ,but  the  aerial coil can  did have two wires emerging from it,one just the right length to reach the tuning condenser whose tuning gang was not otherwise  connected to anything except the grid clip for the first valve  So this lead  proved to be the correct one, the other being the aerial lead.The capacitor  from the plate of the first audio to the grid of the 41 was predictably  leaky and  once replaced  helped sort the distortion and the set ,if it can be called that now goes ,albeit using my bench h.t. supply and bench 6 volt supply.
And it goes surprisingly well. Apart from connecting the wires to the aerial and tuning capacitor and figuring out what to connect to where  no other work was required to get it to go.

So the next task is to explore the vibrator and rectifier side of things. The vibrator is not a plug in one so something new here for me. 
But thanks again to those who helped track down  the identity of what seems to be a rare radio.
All the best everyone.

[Antipodal]

Hello everyone, 
As mentioned in my last post I was going to see if the vibrator / rectifier section could be persuaded to work to make this set "self sufficient". 
We have had some luck here. Initially while the vibrator vibrated , it  seemed  no a.c. was appearing on the rectifier anodes. Checking the  buffer cap across these anodes  showed it to be  very leaky. Replaced with a new 1000 volt  one a healthy a.c. appeared  when the set was powered up  and  with  rectifier plugged in  I measured slightly over 200 volts  between the cathode of the 84 and earth. 
The set is remarkably sensitive especially considering there is no r.f. amplifier.
I have mentioned that there are some differences between the schematic on radiomuseum and this set.The radiomuseum circuit shows a half wave rectifier only. This lends weight to the idea that my set is a later " factory improved " set.

Especial thanks to all who have contributed so helpfully  to identifying and tracking down the make and origins of this set. I'm hoping it will provide an interesting talking point at our next vintage radio club meeting.

[Joe Rossi]

Glad I could help!  Cheers,