Oldtimer question (valves/tubes)

I was trying to remember what exactly it was last night. I *think* there's a EHT generator in there to attract the 'soot' to the paper that can be easily converted into a 60kV taser. But I might easily be mistaken, so don't quote me on that.

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Cursitor Doom
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I really must get around to visiting that place some time. I've heard very good reports of it.

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Cursitor Doom

It's a shame that mostly all the links in the project section point to sites that are gone....

Reply to
three_jeeps

yes, motors, drive pullies, belts, lead screws, stepper motors, microswitches,

Reply to
three_jeeps

formatting link

John ;-#)#

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John Robertson

These simple generators were intentionally distorted. They were over driven for three reasons.

The first was to make sure that the output didn't drop out and kill the osc illation at the high end of each band.

The second was to produce harmonics on the higher bands.

The third was to allow the unit to continue to operate as the tube aged. As far as the coils failing, some adsorbed moisture, which lowered their 'Q'.

Often, the 400 or 1,000 Hz tone was distorted, as well due to the lack of A GC. It gave a distinct sound in the receiver being aligned. Look at what HP did in their 606 and 608 series generators to produce a clean signal. They certainly didn't attempt to do it with two tubes!

I remember the low voltage tubes in car radios. They weren't used for very long. It was an attempt to eliminate the Vibrator derived HV plate supply, without using the more expensive transistors of their day. I think that Phi lco/Ford went that route, while Delco and Motorola went straight to all tra nsistor designs. For used Philco, Bendix and Motorola radios in the '60s an d '70a. BTW, Galvin Manufacturing invented the car radio, then they changed their name to Motorola to reflect their main product line.

Reply to
Michael Terrell

I thought the first car radio was back in the early 20s....seem to recall seeing a picture in a magazine or old encyclopedia (I used to read those for fun as a kid) in the 60s.

The Galvin/Motorola was the first commercially successful radio. Nice to know where that famous name came from, thanks!

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speaks of a car radio in

1924 in NSW, Australia.

John :-#)#

Reply to
John Robertson

5

om

e

the

-

iven for three reasons.

oscillation at the high end of each band.

. As far as the coils failing, some adsorbed moisture, which lowered their 'Q'.

of AGC. It gave a distinct sound in the receiver being aligned. Look at wha t HP did in their 606 and 608 series generators to produce a clean signal. They certainly didn't attempt to do it with two tubes!

ery long. It was an attempt to eliminate the Vibrator derived HV plate supp ly, without using the more expensive transistors of their day. I think that Philco/Ford went that route, while Delco and Motorola went straight to all transistor designs. For used Philco, Bendix and Motorola radios in the '60 s and '70a. BTW, Galvin Manufacturing invented the car radio, then they cha nged their name to Motorola to reflect their main product line.

I had never heard of the 1924 radio. Was it a real car radio, or a battery powered radio installed in a car? I also remember one of the old Roy Rogers TV show episodes with a battery powered radio on a horse that they used to catch the bad guys. I saw that over 50 years ago. ;-)

I remember when Bendix switched from TO-3 output transistors, to TO-220. De spite the warnings not to bend the leads at the case, they did. They had ov er a double digit failure rate within two months of the cars being sold. Th ey used a tiny daughter board, and mounted it in one of the holes for the o riginal package. They were very shitty radios. :(

Reply to
Michael Terrell

I think it was more likely a battery radio that someone jammed into a car. I have a RCA 24 in my collection of early 20's radios that was an early luggable battery radio. Used a few WD-11s and had two spares in a holder - I imagine the tubes did not like being bounced around so spares were really needed!

I had little to do with car radios, mostly I played with home battery radios as a teenager.

How that led to pinball and jukebox sales and service is a mystery...

(well, not really, I LIKE fixing things!)

John :-#)#

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John Robertson

ery long. It was an attempt to eliminate the Vibrator derived HV plate supp ly, without using the more expensive transistors of their day. I think that Philco/Ford went that route, while Delco and Motorola went straight to all transistor designs. For used Philco, Bendix and Motorola radios in the '60 s and '70a. BTW, Galvin Manufacturing invented the car radio, then they cha nged their name to Motorola to reflect their main product line.

The 1924 radio was experimental. Imagine trying to get stable reception wit h a mobile positive feedback circuit set to the brink of oscillation, power ed by either HT dry batteries or a vibrator PSU. Plus the thing had a huge aerial rig over the car. It wasn't a practical commercial proposition.

Of course you can lose the PFB and have a row of valves, but then your HT b attery drain is far worse.

NT

Reply to
tabbypurr

Very interesting, thanks!

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