Valve JAN-7193

[Andrew7773]

Any info on valve. JAN-7193 SC961A it has two top caps base is 8 pin Int-Octal. It was in a signal generator made by Acton Elec in the 1950's
Thanks for any help Regards Andy.

[ms660]

http://www.r-type.org/exhib/aaa0163.htm

Any use?

Lawrence.

[Radio Wrangler]

JAN is American for Joint Army/Navy. Their type is 7193. JAN is printed on lots of American war surplus valves.

Also known as DET20, VR135, or CV6

It's a late 1930s VHF triode. with anode and grid on the caps.

I knew I'd seen some recently and there were two in a box of old stuff up at the radio club. I've got them here to check the numbers for equivalents.

Probably Acton Elec were building products for sale out of government surplus parts.

David

[janpa3fyz]

This triode type was also used in the B-set of the WS19.
The CV6 in the British sets and the E1148 in the US sets.
Jan Terranea PA3FYZ

[G4XWDJim]

The 19 set used one in its VHF 235 mHz section. As a kid in the 50s my mate and I had one of those signal generators. I think it also used the meter from a 19 set. Is the meter mounted in the bottom right hand corner. Maybe other bits too if we could see the innards.

If you're stuck for one of those valves I can find you one.

Jim

[G4XWDJim]

There are other threads on here about the same equipment. Search under test gear Acton.

I found a picture of the sig gen that I think we had as kids. Is this the same as yours?

Jim

[Andrew7773]

Thanks to all for the speed and great info on this valve. I must be slipping its nice to know that there is such great help out there. I too started with 19set in the 50's before starting a life time in the Radio and TV industry, but I had forgotten my roots my father ex signals in ww2 would be laughing now. I blame the years of semiconductors and chips for ruining a good industry bring back droppers and pcl85 and a nice warm workshop with a van to go and get the chips for dinner.
Thanks again.

[Radio Wrangler]

Do you want a spare?

David

[Mark James]

I have a whole tray of these! Anyone know of any good homebrew projects for them?

Mark

[Herald1360]

Headphone amplifier?

RF Sig gen?

[Radio Wrangler]

Pair 'em up as ECC8x 6SN7 alternative for people who want a bit more treble.

No, I think the Classic RF sig gen is a very good application. THe Acton folk got it right.

David

[ms660]

Paint a face on them

Lawrence.

[G4XWDJim]

A good homebrew project -

Build a 235 MHz transmitter to chat to the 19 set boys and lots of others all at the same time.

Jim

[turretslug]

Originally Posted by Radio Wrangler

Pair 'em up as ECC8x 6SN7 alternative for people who want a bit more treble.

I expect that the top-cap connections have made it less appealing to a market that likes valves to be on show, otherwise its derivation and electrical similarity to a classic triode would have led to its quickly being hoovered up.

That construction ought to make for efficient interfacing with tapped tuned lines- I wonder just how high it can go?

I've heard it referred to as the Dalek valve!

[Radio Wrangler]

The long path to the cathode will prove a serious limitation. I understand that at 235MHz they were already well down a reducing power curve.

The audio people really don't like top caps, which is a shame because if we could sell them on 3-500Zs, we could maybe thin down their numbers a bit and make spare bottles for period equipment a bit more affordable. Anything that looks like a 3-500z ought to sound amazing!

David

[paulsherwin]

I also have a signal generator using two of these valves, though not from this company. The valves were made in huge numbers for the 19 set, mostly in America, and though the 19 remained in use as an HF transceiver for a couple of decades the VHF section had already become obsolete by the end of the war. Many thousands of E1148s were dumped onto the surplus market in the late 40s and they were one of the cheapest valves you could buy for a while.

They are actually an attractive valve when working, with a very bright heater. You could build a very exotic looking pantry transmitter with one or two of them.

[Mark James]

Paul .... the pantry transmitter appeals. Any basic circuits to start from for a novice at design?

Mark

[Dave757]

Hi,

It has always puzzled me why there was no size difference between the caps on the 7193, but perhaps it was designed for the 19 set or a similar application where its keyway location would make misconnection impossible.
Of course you can visually check the connections through the glass!

Kind regards

Dave

[paulsherwin]

Originally Posted by Mark James

Paul .... the pantry transmitter appeals. Any basic circuits to start from for a novice at design?

Mark

A simple pantry transmitter is just a modulated oscillator, and it should be possible to use E1148s in many of the American 'phono oscillator' designs. Some of them specify a pentode not a triode but simply removing the extra grid components should be all that's needed.

[Radio Wrangler]

I'm a bit of a supporter of transistors for pantry transmitters for a few reasons:

1) They run cooler and without high voltages, so they're safer when forgotten and left on.

2) The low temperature makes it easier to keep free-running oscillators stable.

3) They're easier to keep the radiated power down to reasonable levels without much screening, otherwise you can spread your signals a bit too widely.

You could certainly make a pantry transmitter ouy of a couple of DET20s, but there are easier ways.

David