'68 Imperial kid's record player

[radiotvnut]

I just picked up this Imperial "one tube wonder" record player from '68. As usual, it is beat up and has the usual problems. It uses a 7-pin 25EH5 output tube and a silicon diode rectifier. The tonearm and platter are plastic and the amp is as basic as a "one tube wonder" can get. This thing probably cost under $10 when new and was probably one of the last tube models.

[bob91343]

And the dropping 'resistor' for the tube heater is the motor winding.

[radiotvnut]

Yes, that's right. The chassis also has a hole for another tube sicket; so, it won't be much truoble to add a preamp stage, if I need to. On some of these, I've been adding an extra preamp stage so that I can use a lower output, more modern cartridge.

[bob91343]

The extra hole may be for the stereo model.

[radiotvnut]

Yes, I forgot that there were a few of these manually operated "one tube wonder x 2" models that were stereo.

[maxhifi]

how is the idler holding up?
on most of my old phonos, they are deteriorated to near uselessness
But mine are older than this one

[dieseljeep]

Originally Posted by radiotvnut

I just picked up this Imperial "one tube wonder" record player from '68. As usual, it is beat up and has the usual problems. It uses a 7-pin 25EH5 output tube and a silicon diode rectifier. The tonearm and platter are plastic and the amp is as basic as a "one tube wonder" can get. This thing probably cost under $10 when new and was probably one of the last tube models.

I never saw one sell for less than $17.95. I wonder if there was a Sams Photo-fact available for it.

[Electronic M]

One could probably draw their own schematic in less time that it took to look up the sam's.

[radiotvnut]

The idler has a notch in it from the speed selector being left in gear. As much as it cost to rebuild an idler, I'll probably clean this one up and use it as-is.

I don't know if this unit was covered by Sam's; but, others were and they all use basically the same circuit. Like what was said before, this one is so simple that I could draw a diagram in two minutes.

[dieseljeep]

Originally Posted by Electronic M

One could probably draw their own schematic in less time that it took to look up the sam's.

I guess it was a poor attempt at humor.

[dieseljeep]

Originally Posted by radiotvnut

The idler has a notch in it from the speed selector being left in gear. As much as it cost to rebuild an idler, I'll probably clean this one up and use it as-is.

I don't know if this unit was covered by Sam's; but, others were and they all use basically the same circuit. Like what was said before, this one is so simple that I could draw a diagram in two minutes.

I just aquired an almost complete Sams library from a shop that was going out of business. Even the big names in the business made or had made these very basic units. Sams sure has a lot of coverage on these items.

[Electronic M]

Originally Posted by dieseljeep

I guess it was a poor attempt at humor.

Okay not funny I guess.......Given I go to the library (two different ones depending on vintage and avaliability) for my sam's and have to call and wait on hold for them to confirm they have it, and that I can draw a decent print for a single tube circuit in a few minutes it would probably take less time for me to draw it than to find out which library has it.

[Jeffhs]

I wonder how many of those "one-tube wonder" record players, like the Imperial phono being discussed here, were susceptible to interference from extremely strong AM radio signals. Imagine listening to your favorite Beatles record on your Imperial (or other brand) one-tube phono, only to hear your area's local AM station in the background -- or, worse, drowning out the sound from the record entirely.

BTW, since most of these one-tube phonos used a 90-volt phonograph motor in series with the tube filament, an open filament would stop the motor in its tracks. If the tube should develop a heater-to-cathode short, the motor would probably have well over 110 volts across it, immediately burning out the winding. An excellent case for fusing the 110-volt input circuit; I wonder why these phonos weren't fused to prevent disasters like this? Wouldn't have added that much more to the cost of an already cheap phonograph, and could have saved the unit from catastrophic failure.

[maxhifi]

my 'one tube wonder' is made by fleetwood in montreal canada, same as my silvertone tv. It's a real united nations of parts - bsr made in germany motor and turntable, tesla 4'' speaker from czechoslovakia, japanese output transformer, canadian 25EH5, USA made Astatic tonearm, and the cheapest possible chassis and controls. The plastic turntable is so light and cheap it wobbles a bit. My califone school player feels like a thorens in comparison.

[dieseljeep]

Originally Posted by Electronic M

Okay not funny I guess.......Given I go to the library (two different ones depending on vintage and avaliability) for my sam's and have to call and wait on hold for them to confirm they have it, and that I can draw a decent print for a single tube circuit in a few minutes it would probably take less time for me to draw it than to find out which library has it.

It seems to be the same thing all over. When I lived in Milwaukee, the branch libraries only had the later Sams coverage, where the main library had all ever issued. Anyone that was into repairing or collecting these items, by now, should be able to troubleshoot a simple amp or AA5 type radio without a schematic.