[bridkarl]

This was sitting as a decoration in the local record shop so it followed me home for $50.
Basically intact including the multicolored rotating glass dial. Obviously the transformer, caps, are trashed and the rest needs to be gone through but it has the original speaker fully intact. Case is ok but needs new veneer on top. 
I dug out the Rider’s pages for this. I’ve never seen it where they actually give you a picture diagram of the entire radio - wiring, parts placement. I’ll have to figure out what kind of transformer I need for this - it’s 115 v input to a 5Z4.


Not that I needed another project but I just couldn’t stand to see this just decaying away in a shop window. I’ll have to research this further while I finish these 41-250 and 41-255 that are presently on the bench.

[David]

Some info from beitmans giving ohms value for the power transformer different input voltages. Hope this helps David    

[bridkarl]

Thanks. This will be a good Fall/Winter project. Someone put on an 8mfd cap instead of the 16 plus some strange (tv?) transformer.Not sure the radio
would even work like that 

 Plus duct tape on the power cord.  Not sure what they were thinking but I’ll get it all sorted eventually. 
I expect the final parts for my two Philco 41-250 and 41-255 projects this week so I’ll get those done and then see about this.

[MrFixr55]

This will be a pretty nice radio. The 5Z4 likely has similar specs to a 5Y3, with the advantage of having a cathode sleeve, making for a more rugged tube. Years ago I had a philco console (Can't remember the year, it had a 10 or 12" Speaker (think it was a 12), Octal and Loctail tubes, pull out grille for the phono, AM and SW (I can't remember if it had the old Armstrong FM Band). Well, I was not in my room where the radio was, the radio was on and the 5Y3 developed a plate to cathode short, burning the transformer. My sister and mother screamed (My little hobby caused them to do that a lot), and Dad's intervention meant nothing. The radio had to go out to the curb, chassis, cabinet, speaker and all (I snuck the tubes and replacement Jensen PM speaker back).

So a transformer for 5 300mA tubes, 2 700 mA tubes and a 2A 5V rectifier is what you need. Unfortunately, the B winding AC voltages are not given, but one from a Philco 16, 116, a similar RCA or Zenith console will do. (Sometimes, I think that all circuits came from RCA engineers, as there are so many similarities among the manufacturers. ) Of course, take it from a hopelessly unrestorable radio.

I am guessing that this radio is ca 1936-1937 which was one of the first couple of years after 1930 that GE built radios instead of sourcing them from RCA. GE sold RCA designed and built radios as late as the 1935 season. (Prior to 1930, RCA sold radios built by GE, Westinghouse and Wireless Specialty Apparatus, as RCA had no manufacturing facilities. In 1929-1930, RCA bought the Victor Talking Machine Company who had just started building radios in addition to phonos. In 1930, an antitrust suit settlement caused the breakup of the GE-Westinghouse-RCA consortium, and part of the deal was that GE and Westinghouse were not to build their own radios for a few years, buying RCA made sets for resale and totally reversing the previous operation.) In addition, GE was an early proponent of metal tubes. I do not know whether GE or RCA actually invented the metal tube. RCA may have claimed that they invented the metal tube but, as one Phorum member said, RCA claimed to invent the electron!

[David]

Duck Tape can fix everything.

[bridkarl]

I’ve included the circuit. Pretty standard. I’m
figuring I need about 700 v plus 5 v for the rectifier and the normal 6.3 filament voltages. It’s positively the last thing I’ll need to get to - no point in powering this up until I get the caps etc done. This Hammond gives an idea of what I think might work if I get a new transformer. 

I’m including a list of transformer wiring color codes. Might be useful to someone.

[Arran]

The original transformer was likely a horizontally mounted one, unfortunately most of Hammond's offerings are not so you would have to make a mounting plate to cover the hole in the chassis, or it will look like the grey one which was bucksheed in there. However AES sells replacement power transformers for guitar amplifiers which are horizontally mounted, so it's usually a question of picking out the one with the right voltages and current ratings, so seven 6.3 volt tubes, plus a 5 volt rectifier. So five 300 ma tubes, and two 700 ma tubes, which equals 2900 ma, or 2.9 amps for the tube heaters. It's a sort of silly design, they used a 6F5 and a 6H6 when they could have used a 6Q7/6R7, if they had used a 6Q7, and a 6F5 they could have eliminated the interstage transformer, this seems to have been a fad around 1937-38 to "tube stuff" chassis this way just to boost the tube count, but not really doing anything useful.
Regards
Arran

[bridkarl]

I may have a lead on the transformer from
an A-81 which is basically the same 1936 GE radio in a different case. If not I’ll follow your suggestion.