An old timey radio

Hi Bitrex, You might be interested in looking at this forum,

Where do you buy those tubes? A guy on Ebay wants 15 bucks for a 12AL8, not exactly cheap.

Over 6W for the 12AL8 filament alone won't get you an energy start rating on the radio :-)

I can remember 90V BATTERIES ;-)

And I've owned several cars with vibrator generation of the plate supply. ...Jim Thompson

But I just remembered that my 1961 Renault Dauphine had an AM radio with 12V plate supply... made by Automatic Radio (Boston, MA)...

I have one of these radios:

See? There were actually integrated circuits before you were born :-)

Oh yeah, those vibrator cartridges you had to replace once in a while.

The schematic won't open. What's that transistor doing on its side?

I never had to replace one. The nicest was in a 1950 Nash (I bought it in 1956). The radio was mounted in the trunk with a big woofer on the rear window deck. The vibrator supply used the field coil of the speaker as the power supply choke ;-) ...Jim Thompson

It's a PNG, but impossible to blow up to readable size.

That's the audio output device... 2N176... class-A :-) ...Jim Thompson

That car must have been a chick magnet back then :-)

The front seats would fold back flat to make a bed ;-)

But that radio would kill battery in about an hour. I always parked on a downhill slope (*), so I could coast and pop the clutch ;-)

(*) Easy to do in WV (8-) ...Jim Thompson

Search for "subminiature tubes". Not exactly 12 volt tubes but most work with 40-60 volts.

They were pretty robust-- I remember wiring one up in series with the

Best regards, Spehro Pefhany

Yikes, what is that, an untuned RF amp and a regenerative detector?

That is very weird in several places.

John

Sure, submins you can get. They must have opened lots of bunkers in Russia because things like nuvistors show up by the boxload on auction sites. But they won't be very good with a 12V plate voltage either.

When I rented my first car in America (Chevy Nova, the small model) and the seat would not do that I asked the car rental guy. Because EU cars could nearly always do that back then. He said it was purposely not done, to discourage people from camping in their cars.

Most of the time I didn't even have a battery in my Citroen. It was either downhill or muscleing the crank. Thumb always _over_, else ...

Guessing the filament needs current regulation. A 1.5V battery, fresh, might yield a short, bright flash instead. And with only 5 wires to it, I'm guessing these 'pentodes' are usually used the easy way out and wired up as triodes?

Jon

There were quite a few car radios using 12v ht around the crossover period from tubes to transistors. The ones i've seen (Motorola, Radiomobile ?) used transistors for the audio stages, but the performance was never as good as tubes with real ht. they were the last gasp of tubes in mobile equipment before the great wave drowned them all.

Fond memories of one or two valve trf sets with reaction control. Age

Regards,

Chris

They weren't cheap in the '60s or '70s, either.

Thirty-nine pounds? Wasn't that like a king's ransom in 1926? Like, equivalent to about three grand today? ;-)

Thanks, Rich