Scaler with Dekatron Counter

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Mac Doktor

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Apr 19, 2023, 1:02:04 PM4/19/23
to neonixie-l
I just received this:



Appears to be working. The HV rotary switch is stuck. Dekatrons light up. 

The seller has another listing which includes a scintillation probe:



The scintillation probe is a crapshoot. The crystal may be good, it may be bad. I have one that's working. Need to fix that switch.


Terry Bowman, KA4HJH
"The Mac Doctor"


“...the book said something astonishing, a very big thought. The stars, it said, were suns but very far away. The Sun was a star but close up.”—Carl Sagan, "The Backbone Of Night", Cosmos, 1980


Dekatron42

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Apr 19, 2023, 2:16:15 PM4/19/23
to neonixie-l
Nice catch!

Did you get any sort of documentation with it?

I have a bunch of those counters but only one amplifier, like the in the second auction, and a bunch of different probes plus a bunch of different shields/holders for the probe above the sample being tested, made from aluminum and lead mostly.

The most common failures have been the 6BG6A tubes being poor after long usage and a few transistors that have been blown. The plastic window in front of the mechanical counter tends to come loose and drop inside the case and that means that dust enters the mechanical counter which makes it count poorly. Apart from that all of mine are working flawlessly.

/Martin

Mac Doktor

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Apr 19, 2023, 2:24:11 PM4/19/23
to neonixie-l
On Apr 19, 2023, at 2:16 PM, Dekatron42 <martin....@gmail.com> wrote:

Did you get any sort of documentation with it?

Of course not. ;)



The plastic window in front of the mechanical counter tends to come loose and drop inside the case and that means that dust enters the mechanical counter which makes it count poorly.

Still in place on this one. Without the analyzer I have no way to hook my probe up. I know where to find the circuitry but then I still have to come up with HV connectors and cables. 


gregebert

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Apr 19, 2023, 4:30:30 PM4/19/23
to neonixie-l
Historical mix of assembly techniques....PC board (looks single-sided), point-to-point components on sockets and terminal strips.
Does it have that wonderful aroma of conformal coating often found in vintage equipment ?

Too bad it doesn't have 6 or 7 dekatrons instead of 5. Would have made a neat clock.

Mac Doktor

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Apr 19, 2023, 5:13:00 PM4/19/23
to neonixie-l
On Apr 19, 2023, at 4:30 PM, gregebert <greg...@hotmail.com> wrote:

Historical mix of assembly techniques....PC board (looks single-sided), point-to-point components on sockets and terminal strips.
Does it have that wonderful aroma of conformal coating often found in vintage equipment ?

Not that I can tell. I assume that the only reason there are tubes in this thing is for the HV supplies. Correct me if I'm wrong.

Looks like someone replaced a bunch of capacitors which should make things a bit easier. A schematic would be nice.


Too bad it doesn't have 6 or 7 dekatrons instead of 5. Would have made a neat clock.

Terry Bowman, KA4HJH
"The Mac Doctor"


"If only you could see what I've seen with your eyes."—Roy Batty, Blade Runner

Nick Andrews

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Apr 19, 2023, 6:03:51 PM4/19/23
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Some serious boat anchors there!

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Mac Doktor

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Apr 19, 2023, 6:14:17 PM4/19/23
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On Apr 19, 2023, at 6:03 PM, Nick Andrews <nickja...@gmail.com> wrote:

Some serious boat anchors there!

Museum pieces. Seriously.


Terry Bowman, KA4HJH
"The Mac Doctor"


Nick Andrews

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Apr 19, 2023, 6:19:32 PM4/19/23
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Certainly!  If you can afford the shipping, that is.  So what's missing from the HP units?  Those plug connectors are familiar...

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Mac Doktor

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Apr 19, 2023, 6:29:50 PM4/19/23
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On Apr 19, 2023, at 6:18 PM, Nick Andrews <nickja...@gmail.com> wrote:

Certainly!  If you can afford the shipping, that is.  So what's missing from the HP units?  Those plug connectors are familiar...

I'm not sure what you call it but I guess it amounts to an analog "pre-scaler". They made these up to ten decades. My 521A only has four but that's enough for H:M, right?

Nick Andrews

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Apr 19, 2023, 7:47:21 PM4/19/23
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Hmm...

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20230404_215458.jpg

Mac Doktor

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Apr 20, 2023, 11:48:07 AM4/20/23
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On Apr 19, 2023, at 7:46 PM, Nick Andrews <nickja...@gmail.com> wrote:

Hmm...

I think that's the first time I've been able to read the lettering and there are lots of them on eBay.


Terry Bowman, KA4HJH
"The Mac Doctor"


Nick Andrews

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Apr 20, 2023, 3:11:14 PM4/20/23
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I picked up three of these HP counters and another from govt auction cheap because of the nixie displays.

HP5214L Preset Counter
HP 5243L with 5262A Time Interval Unit plugin
HP 5245L with 5252A Prescaler plugin
NMC PC-4 proportional counter

Now I know to keep an eye out for them in the future.  Really need to get stuff cleaned up so I can set these up and test them for function.

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Tidak Ada

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Apr 20, 2023, 3:47:59 PM4/20/23
to neonixie-l
A long time ago (55 years), I had to use this Picker counter at university.
We had to calculate the half-life decay of Cesium-137
I get still a raise in hartbeat as I remmeber the reading of those running dots.

Who in hell has devloped this ugly machine....?

eric
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