Truetone D-925

[electra225]

This small console radio belonged to my grandmother's cousin, Hershel. He was a farmer and would hire me on occasion to pitch hay bales or do other chores. He liked listening to the Chicago White Sox on radio. This radio was out on his front screened-in porch. You could close the windows for winter, or slide them open for screens in the summer. We would come to the house when the White Sox played. Hershel would get us each a big glass of sweet tea and we'd listen to the radio. I have had this thing probably close to 40 years, and have never used it much. It is pretty much original. Built in 1935, I think by Belmont. The four bushings that stabilize the tuner are all shot. That will be the first thing I'll have to address. Then it needs a good cleaning. I will try to re-stuff the filter caps, since there really isn't room to put terminal strips under the chassis. The dial string is still there and in good shape, so that's good. I'll change the filter caps, then power up and get a baseline of operation before I go any further. Everything, so far, looks good, just really dusty and dirty. This is an eight-tube chassis with eye tube. 6N6 P-P output and an eight inch speaker.

[TC Chris]

Found photos online-- a handsome device. They had a lot of tubes but more for audio than for RF. No tuned RF amp. Get yours going!

Chris Campbell

[electra225]

I've got pictures, but was too lazy to upload them.

[electra225]

I worked on this old radio most of the day today. I was choring some, so I guess it was part of the day, whenever I was not on "Honey-do" duty.

As you can see in the pictures, I cut the filter cap cans apart and restuffed them. After I did the first one the hard way, I found I could cut the wires, then unscrew the can from the chassis. The nut that holds it tight is soldered to the chassis. Restuffing the second one took a third the time the first one did. I powered up slowly once I got the filter caps done, first with the dim bulb and KAW, then without the dim bulb. By the time I got to 90 volts with the rectifier in, the radio started playing. It actually sounds pretty good. Badly out of alignment, with dirty band switch and tone control. I replaced one coupling cap that I broke off while I was tinkering with the filter caps. I need to get a print of the diagram so I can properly align it. I believe this will be a good performing radio. Looking at the plate on the rear of the chassis, it says it was built by "D Corp, Detroit Michigan". Perhaps not Belmont, but maybe Detrola? The speaker is prinstine for being a 1935 model.

[electra225]

Here is a picture I forgot above.

[TC Chris]

Wait... three-gang tuning cap but no RF amp tube? Maybe I had the wrong schematic?

Chris Campbell

[William]

It looks great, Greg. Nice Job! I find it interesting that it has an input for "phono" or "television". I get "phono", but "television"? From what I have read RCA was the first to commercially introduce TV and that was 1939. Maybe this radio was just planning for the future.

Bill

[Motorola minion]

What a neat chassis, the brands we never see are often a surprise. I have NIB 6N6 tubes but never knew what used them.

Medium wave is same as broadcast. I like how it has longwave band scale in middle, not sure that LW was used in USA.

[electra225]

Chris, I don't have a diagram for this chassis, but it appears to have a tuned RF stage, just no an amplified tuned RF stage. The front end seems stout. I have never seen a set quite like this one. The chassis is crowded, but appears to be well-built. It has a friction drive setup for the tuning mechanism, which I took a shaky picture of. I really need to invest in a tri-pod. I can't hold the camera still anymore. I do better with my phone in that regard, but I prefer using a camera. I trust I have the bushings in the tuner mountings in the correct location. The old bushings had turned to mush and most of them were laying under the chassis when I took it from the cabinet. There is relatively generous room where the pushbuttons pass thru the cabinet. One pushbutton looks "pretty breakdownable". I'm sure they are unobtanium, so I need to come up with a plan on that. I made a masonite back for the cabinet to keep cats out of the speaker. I gained cobwebs, so that needs attended to. I don't own an air compessor yet, but a good puff of air would do wonders in the tuning capacitor. The lower end of the dial is weaker than the upper end, so alignment is indicated there. This radio still runs the tatty antenna wire that was on it when Hershel listened to the White Sox 60 years ago. I asked him then why he didn't fix that wire. He said it didn't do anything, so it wouldn't short out or hurt anything like it was. And, I still need to find a spot where I can put a fuse.

If this radio is from 1935, it uses a pentagrid converter, a 6K8. Then a 6K7 If amp, 6Q7 detector, first audio, AVC amp, a 76 audio amp, phase splitter with 6N6 P-P audio, all fed to an eight inch speaker. It uses an 80 rectifier and a 6U5 eye tube. All the tubes are branded Truetone except the rectifier. I don't see codes on the tubes. The tube numbers are mostly gone for some reason. I have to label the tubes with tape when I remove them, so I have no idea who made the tubes. Radios from 1935 typically employed a separate oscillator and mixer so they could increase their tube count. If I were building this chassis, I'd have used an RF amp then used a single-ended output, maybe a 6F6. I will give that little speaker its due. It puts out a lot more bass than I figured it might.

As a potentially interesting aside, I took a shot of my box of tuner bushings. I got a small paper bag with a considerable number of universal-fit tuner bushings when George Fathauer owned Antique Electronic Supply on 1st Street in Tempe. That must have been in the early 1980's. These are all I have left. I forget now how many I bought at the time, but I figured they would last me three lifetimes. I'd like to both have more bushings and to be able to have a conversation with George. That man was amazing the things he knew about radios. He always had time for a conversation. Ours were typically about the converter stage in a radio. I still have problems wading thru that stage at times.

Another feature of this chassis that I appreciate is that fact that the tuner, tuner drive system, the dial backing, are all made in one piece. Most times, when you replace the tuner bushings you have to then make everything else work again. This was all in one piece. I unsoldered two wires and the whole assembly came up together. I replaced the bushings, did a little cleaning, then put it all back. I didn't have to mess with the dial string, a major blessing.

[electra225]

I have the electronic components replaced, ready for an alignment. I cleaned controls, which helped considerably. I made sure all the tube sockets are clean. The radio-phono switch works well with no noise or intermittent operation. This chassis draws 90 watts. The PT gets warm after it runs two or three hours. I installed a fuse. 1 1/2 amp is the smallest fuse I had. My supply of one-amp ones needs to be replenished. I'm also now out of fuse holders. I printed the diagram from Nostalgia Air, so alignment is the next step. I 'll finish cleaning, them put the chassis back into the cabinet.

[TC Chris]

I 'll finish cleaning, them put the chassis back into the cabinet.

Looked pretty spiffy already in your photos.

Chris Campbell

[electra225]

Thanks, but I haven't shown the dirty spots.....

The diagram lists the year of manufacture as 1939. That would follow, given the TV sound input. 1935 might be a bit early for TV sound, yes? Hershel, or somebody, wrote "1935" on the sticker in the cabinet with the tube layout on it. And I now believe it was built by Detrola. I'm headed for the shop in a few minutes to try and complete the alignment.

[electra225]

I let the signal generator, VTVM and the radio chassis to warm up probably an hour while we ate breakfast. The alignment went well and I'm satisfied with its performance. The chassis is back in the cabinet and it's all buttoned up. A cool feature of this radio I had forgotten about is that the dial lights also light up the pushbuttons. This thing may give my Philco 40-180 a run for its money performance-wise.

[William]

Congrats, Greg, on a job well done. Someday I need to learn how to do an alignment as most of the old radios I have done do not perform all that well.

Bill