Temple model 8-90

[TC Chris]

Yay for DIY solutions. Somewhere I read about using coffee filter paper for cone repairs. It's strong (retains its strength when boiling water soaks it). Your radio is in very good condition, original I assume, and has value even if it would not command a high price. It is always interesting how technology advances. These radios came along as radio transitioned from a hobbyist activity to a mass entertainment medium. People with no electronic knowledge did not want to deal with batteries (A batteries were often lead-acid and messy; B batteries were expensive; some even had C batteries for bias) or multiple dials. The AC-powered, one dial TRF radio made radio available to all. A bit later, the dial got crowded, and superhets were far superior in selectivity. But for a while, these radios were the home entertainment centers of the day.

It's worth remembering that when houses were first wired for AC, it was intended for lighting only; appliances were run from screw-in plug adapters until it became obvious that outlets for devices made sense.

Chris Campbell

[electra225]

The upper end of the dial out here is fairly crowded. Antenna strength with a TRF radio is very critical, particularly if you want to pick a weaker station out of stronger ones. "The Bull" that broadcasts Western Red is at 1340, and there is a strong blab station at 1360. With a superhet, this is no big deal. The Bull is stronger, but the other station still interferes with the TRF set unless I use my longer antenna. I think the fidelity on a TRF is better, since there is no oscillator to make birdies or other interference. The TRF set won't drift like a superhet will. I like the old radio. It has P-P 45 output, which is the most valuable part of the radio. The output tubes are engraved Philcos. $$$$$$$....

[Dr. Radio]

Just saw this post now.

When I first saw your pictures, I thought it might have been the same radio used in the episode titled "Static" in the original Twilight Zone series!

[Motorola minion]

Since the original post, I passed an antique place on Lincoln Highway west of Bedford, that had a Temple sitting outside on a covered porch, with the 45s intact.

I would have offered them $30 for it had they been open. The cabinet was nicer than mine too. I will be by there again soon

[electra225]

I'm going to "test drive" my speaker repair tomorrow. The only thing I can see not being satisfactory about the repair is one place I had to repair that may make the cone stiff. If that is not an issue, I don't see why it won't work. So, now we know where there are three of these sets? I had never seen or heard of one before I got mine.

[electra225]

My repair kluge was 95% successful. The audio might be a tad more mumbly than it was. It doesn't sound like the Concert Grand, but then it never did. Antenna strength has a lot to do with audio quality. The LED light on my bench lamp messes with this radio. I need a long antenna to get stations on the lower end of the dial, hardly any antenna for it to perform well on the upper end of the dial. I listened to Western Red on this old radio today, the entire three hours. The dial light wasn't working last time I used the radio. I removed the bulb and it checked good. I rubbed the contact of the bulb on my pants, now it works. I was listening to Western Red on "The Bull" at 1340 AM. All I used for an antenna was a test lead connected to the chassis of the radio setting next to it. This radio badly needs a tone control. The audio could stand to be a little brighter. If I was going to run a 1928 radio all day, every day, the speaker should be reconed.....

[William]

It's amazing that something from 1928, basically untouched, is still working. How does that happen, and today any electronic anything gets tossed as soon as it fails because it can't be fixed. What a waste our world has become.

Bill

[electra225]

This thing is still running on its original filter caps. I haven't checked wattage draw lately, but it ran for more than three hours and the only hot part on it was the rectifier tube and the 45's. The power transformer on this thing is like you see on welders. Both the primary of the PT and B+ are fused from the factory. The volume control varies the signal to the front end, rather than varying the signal to the audio section. If I turn off the light on my bench, the audio on this radio is cleaner than that on a superhet, since there is no local oscillator to create birdies in the audio. It is kinda too bad the radio snoots don't like these sets. They really are amazing, considering their being as primative as they are.

[William]

Greg, would this Zenith radio be considered a TRF?

https://www.radiomuseum.org/r/zenith_760_ch_2054.html

Bill

[electra225]

No, the description says it's a superhet.

The best way to tell a TRF set is that it doesn't have IF transformers. And, typically, the tubes are lined up in a neat row, instead of being placed all over the chassis. All a TRF chassis does is to take the RF signal broadcast by the station, amplifies it, sends it to the detector, then sends the audio to the audio section. This Temple radio has four stages of RF amplification (#24 tubes) than a #27 detector, #56 first audio, then P-P 45 output, with an 80 rectifier. The advantage to a superhet is it separates stations better. And it has AVC.

[William]

Thanks, Greg, I guess I missed it saying it was a superhet. I have that radio setting in the basement, I picked it up about 5 years ago at a local estate sale for ten bucks. I'm not sure what I will ever do with it, but it looks nice just sitting there looking old.

Bill

[electra225]

Are you considering fixing it?

[William]

Not really, but if I ever do it's a long way off.

Bill

[electra225]

Bring it up easy on the Variac, KAW and dim bulb. Get a baseline on it. You may have to replace the filter caps, but after that you should be able to get a baseline on it to let you know where you are when you started. Take it from there. That radio is earlier than the ones with the wimpy power transformers and rubber wiring. Might not take much to get it going.

[TC Chris]

This radio badly needs a tone control. The audio could stand to be a little brighter.

Consumer AM radios often had a "quality" capacitor tucked into the audio circuits to limit high-frequency response. People were not used to or expecting extended-range audio in those days, and limiting HF response kept out atmospheric noise and such. Sometimes there's a cap across the OPT secondary, or maybe they ground-out the HF ahead of the final amp, or sometimes they use coupling caps that limit HF levels. In theory, TRF radios are capable of wider bandwidth than most superhets, and could sound better on good program material. Seems to me that Heath made a "hi-fi AM" tuner that was a TRF, intended for local reception with a wide audio frequency range.

Right now my trusty superhet GE Superradio II is playing the Grand Ole Opry broadcast from WSM like it's right next door.

Chris Campbell

[TC Chris]

It's amazing that something from 1928, basically untouched, is still working. How does that happen, and today any electronic anything gets tossed as soon as it fails because it can't be fixed. What a waste our world has become.

I've said this before, but I've got a 1924 Crosley VI that will pull in WSM in Nashville. Two tubes, regen. circuit. Very simple and approaching 100 years old.

Chris Campbell

[electra225]

i have never used a regenerative radio. I have also never driven a Ford Model A nor a model T. My stepdad liked the three-dialers. He had a Radiola III-A that he really liked. This old Temple radio is the oldest one I have had or have used.

[TC Chris]

My first radio build, a Knight-Kit "Space Spanner," is a regen set. Three tubes, one of which is the rectifier and does not really count. One is the amplifier. The third one does all the RF heavy lifting.

The subject just pushed me down a rabbit hole, looking at online info regarding my Crosley VI. As far as I can tell, it had one RF tube and one amplifier. (No rectifier: they did not exist then. You had batteries. Me, I have an ARBE power supply for these old-timers. ) So this and the Space-Spanner are design cousins.

Chris Campbell