Elesta EZ10/A/B tester refurbished!

[Dekatron42]

Hi All,

Today I finished restoring my EZ10/A/B tester that I bought a while ago.

It is a small and nice box that makes it possible to test how the EZ10/A/B under real working conditions. The tester is built around a very simple circuit (two circúits in fact, one for EZ10 & EZ10A and one for EZ10B incorporated into one circuit) the circuit for the EZ10B and power supply can be found in the "Elesta technische mitteilungen Die dekadenzählröhre EZ10B nr 17 februar 1961", and the circuit for the EZ10A can be found in the book "Elektronische zählschaltungen" by Konstantin Apel and in the Elesta EZ10/A datasheets.

The tester consists of a power supply that can be adjusted so that the working conditions are calibrated, a driving stage which is controlled by a push button, a switch which selects either EZ10 & EZ10A or EZ10B and an Anode current potentiometer that sets the operating point. All of these parts come straight out of the Elesta information except that the power supply has been modified to only use one high power wire wound potentiometer for setting the voltage used for the guide bias and driving stage. This then results in that the anode voltage for the EZ10 is just added on top of this voltage by the second winding and not regulated at all, so it gets a bit higher than the 580V in Elesta information.

After having tested all of the components I decided to replace almost all of them, the tester was moldy and had a foul smell to it when I got it so it had not been stored well over the years, this had affected all of the resistors and capacitors badly as well as the outer tape layer of the transformer. Some resistors were more than 40% out of tolerance and a few capacitors were either working better as high ohms resistors and some were 600% out of tolerance! After having replaced them it worked like designed.

To test an EZ10/A/B you turn the Anode current control to the left stop, select the type of EZ10 you want to test with the EZ10/A | EZ10B switch, then set the Calibrate/Test switch in the Calibrate position and turn on the power. Now you adjust the voltage control so that the needle hits the red dot at 1.6mA. Then you can put your EZ10/A/B in the socket and switch to the Test position and adjust the Anode current control to the test currents: 1.1mA, 1.3mA or 1.6mA for the EZ10/A or 1.3mA, 1.6mA or 1.8mA for the EZ10B and the push the Key switch so that the glow is chased around the tube twice - just as it says at the end of the label taped to the front panel!

There is really nothing magical about this tester but the information on how the EZ10/A/B's were tested is very nice to have and also the pin straightener on the front is very good to have.

I've tested a bunch of my EZ10A/B's now and found two flaky EZ10B's, one turned out to have a loose pin that got stuck in the test socket! No wonder that one didn't count properly!

I've included a few photos and also the schematic plus the text at the front if anyone wants to have a go at the missing pieces where the label has been torn. I think that the first word might be either "Keep" or "Use" and the last word "pin" but I haven't been able to figure out more even though I have been trying to push the torn pieces around.

/Martin

[Instrument Resources of America]

How does ""Use gauge to straighten pins"" sound to you??? Ira.

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[Instrument Resources of America]

P.S. very nice restoration job. Where is the schematic that you say is
posted. I do NOT see it. Thanks, Ira.

On 2/9/2014 2:25 PM, Dekatron42 wrote:

[Dekatron42]

Hi,

Thanks!

The text fits perfectly!

The schematic is in the PDF-file, fourth file named "Elesta EZ10A-B Tester.pdf".

/Martin

[Tidak Ada]

Hi Martin,

 

Thats great news! A verry interesting tester. I have here a couple of EZ10B's that I want to set in a pre scaler for a clock project.  I have a 4MHz TCXO that I have to scle down to 4, 2 ,1, 1/2 and 1/4 Hz. The first stage will be unfortunately made with some TTL, because of I dont know there is any tube that is able to do the job.

Can you sserve me with copies of applicable information from teh books you mention?

Please keep me informed!

 

eric

---

From: neoni...@googlegroups.com [mailto:neoni...@googlegroups.com] On Behalf Of Dekatron42
Sent: zondag 9 februari 2014 23:26
To: neoni...@googlegroups.com
Subject: [neonixie-l] Elesta EZ10/A/B tester refurbished!

[Dekatron42]

Hi,

The Elesta document can be downloaded from Dieter here: http://www.tube-tester.com/sites/nixie/dat_arch/EZ10A_EZ10B.pdf (not a good scan but the only one I found for download), the book by Konstantin Apel can be bought cheap on Ebay now and then and also at places like Abebooks for around $10-20 plus shipping, there are two editions, one from 1961 and one from 1967 that I know of, they are both interresting as they contain a few different circuit diagrams.

/Martin

[Jon]

Super job Martin - it's a lovely box, and good to see it working again.

I wonder if the missing text is "Use gauge to straighten pins". It fits grammatically with the phrasing of the other items on the note, and seems a fair fit to the visible handwritten text.

Jon.

[Dekatron42]

Hi Jon,

Ira beat you to the solution by a few minutes, but a big thanks as now two people have guessed the same sentence and I tried it out in my image software and used text from other portions and it fits very well!

/Martin

[Jon]

Oops - didn't see Ira's post from a few minutes ago. SNAP !

Probably right then.

Jon.

[Tidak Ada]

Hi Martin,

 

OK, I will look for that books. Sadly only books in Italian language. I can't read that language...

If you have a link please let me know.

 

In case you have Dieter's in formation, I enhanced it with Photoshop, so if you like.... It is better readable, but sadly not enough for an OCR.

Further there are some very interesting pages in Dance's book.

 

eric

 

 

---

From: neoni...@googlegroups.com [mailto:neoni...@googlegroups.com] On Behalf Of Dekatron42

Sent: maandag 10 februari 2014 0:16
To: neoni...@googlegroups.com
Subject: Re: [neonixie-l] Elesta EZ10/A/B tester refurbished!

Hi,

The Elesta document can be downloaded from Dieter here: http://www.tube-tester.com/sites/nixie/dat_arch/EZ10A_EZ10B.pdf (not a good scan but the only one I found for download), the book by Konstantin Apel can be bought cheap on Ebay now and then and also at places like Abebooks for around $10-20 plus shipping, there are two editions, one from 1961 and one from 1967 that I know of, they are both interresting as they contain a few different circuit diagrams.

/Martin

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[Dekatron42]

Hi,

You can find atranscript here: http://www.radiomuseum.org/forum/die_dekadenzaehlroehre_ez10b.html.

The book by Konstantin Apel is available at Abebooks, found four copies now where two are of each edition, http://www.abebooks.com/servlet/SearchResults?an=konstantin+apel&sts=t .

/Martin

On Monday, 10 February 2014 00:30:19 UTC+1, Tidak Ada wrote:

[Instrument Resources of America]

You are very welcome, and glad that I could help.   Ira.

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[Tidak Ada]

Hi,

 

I've found a 1961 issue in Belgium and ordered that directly at the seller.

 

Thanks for all your help

 

eric

---

From: neoni...@googlegroups.com [mailto:neoni...@googlegroups.com] On Behalf Of Dekatron42

Sent: maandag 10 februari 2014 0:39

To: neoni...@googlegroups.com
Subject: Re: [neonixie-l] Elesta EZ10/A/B tester refurbished!

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[John Rehwinkel]

> I have a 4MHz TCXO that I have to scle down to 4, 2 ,1, 1/2 and 1/4 Hz. The first stage will be unfortunately made with some TTL, because of I dont know there is any tube that is able to do the job.

I can think of lots of tubes that can do that easily. I'd probably use miniature dual triodes for size reasons.

- John

[Tidak Ada]

John,
Concerning thermionic tubes you are right, but my goal is to use only cold
cathode tubes, surely not in the last place to keep power consumption low.
A divide by 10 counter, even with submini's or Nuvistors consumes a lot of
Watts...

eric

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[Dekatron42]

Eric,

One subminiature thermionic valve will not draw much more power than an EZ10B!

I understand if you want to keep it all cold cathode, I did the same a few years ago but never found a cold cathode tube that worked at those speeds in an oscillator circuit. There are a lot of books on crystal oscillators and I think that you could use a crystal oven with either a 1MHz or 100kHz crystal and have a very stable oscillator with those, the TCXO might be somewhat better but with the lower frequency you can just copy a circuit from any old frequency counter.

/martin

[Tidak Ada]

Martin,

 

Yes one, but the number needed for a divide by ten counter makes it much more power consuming.

The same applies OCXO's and a Rubidium standard.

 

May be I want to make the oscillator to precise, but the final design will probably be quite difficult to set at the right time, so I like to avoid that with a very accurate time keeping element.

 

Thanks for thinking along with me,

 

eric

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Sent: maandag 10 februari 2014 13:02

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[John Rehwinkel]

> Concerning thermionic tubes you are right, but my goal is to use only cold
> cathode tubes, surely not in the last place to keep power consumption low.
> A divide by 10 counter, even with submini's or Nuvistors consumes a lot of
> Watts...

You're quite right of course. But since you had neglected to specify cold cathode tubes, I couldn't resist jumping in.

- John

[Dekatron42]

Eric,

You could build a phantastron circuit with tubes, similar to the dividing stages used in for instance the Tektronix 180a Time-mark Generator, they are quite precis with quality components and easily divide by ten, or whatever number they can be tuned to by selecting component values. The phantastron uses a lot less tubes compared to a binary divider.

/Martin

[Tidak Ada]

Hmm could be, but despite I have heard about it, I am not familiar with the Phamtastron circuit. Does it deliver a sine or an block/pulse at the output?

I have to look for some clear theory.

 

eric

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From: neoni...@googlegroups.com [mailto:neoni...@googlegroups.com] On Behalf Of Dekatron42

Sent: maandag 10 februari 2014 16:22

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[David Forbes]

On 2/10/2014 12:44 PM, Tidak Ada wrote:
> Hmm could be, but despite I have heard about it, I am not familiar with the
> Phamtastron circuit. Does it deliver a sine or an block/pulse at the output?
> I have to look for some clear theory.
>
> eric

Eric,

Google does not help with the Phantastron, as someone borrowed the name for a
product.

The circuit is also called a Miller sweep circuit. It is used in oscilloscopes,
and in old digital pulse circuits as a frequency divider. A pentode tube
generates a sawtooth wave, and is triggered to reset by a synchronizing signal
only when near the end of the sweep.

Look at any old HP frequency counter for a decimal divider using the
Phantastron. They were also used in early television sync generators. This is
why the old television line count was a product of small numbers such as the
US 525 line TV: 525 = 5 * 5 * 7 * 3.

--David Forbes

[Dekatron42]

Eric,

You can download the HP 521a frequency counter manual here: http://bama.edebris.com/manuals/hp/521a/ which has a description of the Phantastron circuit. You can also download the Tektronix 180a manual here: http://bama.edebris.com/manuals/tek/180a/ and have a look at the circuit diagram and also the description in the beginning about the frequency division.

/Martin

On Monday, 10 February 2014 20:44:38 UTC+1, Tidak Ada wrote:

[Tidak Ada]

Yes, I found a HP pre-nixie counter that uses it, but no clear theory.

eric

-----Original Message-----
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Behalf Of David Forbes
Sent: maandag 10 februari 2014 21:00
To: neoni...@googlegroups.com
Subject: Re: [neonixie-l] Elesta EZ10/A/B tester refurbished!

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t.

[Tidak Ada]

Hi Martin,

 

Sadly they are .djvu files, I cannot open them as a Acrobat-8 user.

Sadly I don't get the hit of this afternoon again. Google is strange...

 

eric

---

From: neoni...@googlegroups.com [mailto:neoni...@googlegroups.com] On Behalf Of Dekatron42

Sent: maandag 10 februari 2014 21:33

To: neoni...@googlegroups.com
Subject: Re: [neonixie-l] Elesta EZ10/A/B tester refurbished!

[David Forbes]

Eric,

I have a textbook "Digital Logic Circuits" or similar that describes it in
depth. I will see about scanning it.

[Grahame Marsh]

I don't know eher this was clipped from and it might just be a copy of what you have already.

I've built a few dividers down to 1Hz and they work phantastically. Always use the 6AS6 and not just any pentode.

Grahame

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[Tidak Ada]

Would be nice David!
I hope it doesn't cost too much of work, but I really appreciate your offer.
Even if I decide not tu build it it will be fine reading

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[David Forbes]

On 2/10/14 3:03 PM, Grahame Marsh wrote:
> I don't know eher this was clipped from and it might just be a copy of
> what you have already.
>
> I've built a few dividers down to 1Hz and they work phantastically.
> Always use the 6AS6 and not just any pentode.
>
> Grahame

I have an 8 page textbook section. I'll scan it all in tonight.



--
David Forbes, Tucson AZ

[Charles MacDonald]

On 14-02-10 04:24 PM, Tidak Ada wrote:
> Hi Martin,
> Sadly they are .djvu files, I cannot open them as a Acrobat-8 user.

There are stand alone .djvu readers for most operating systems...
http://djvu.org/resources/

The adobe PDF readers tend to now play nice with others.

--
Charles MacDonald Stittsville Ontario
cm...@zeusprune.ca Just Beyond the Fringe
http://Charles.MacDonald.org/tubes
No Microsoft Products were used in sending this e-mail.

[David Forbes]

On 2/10/14 2:58 PM, David Forbes wrote:
> Eric,
>
> I have a textbook "Digital Logic Circuits" or similar that describes it
> in depth. I will see about scanning it.

Here it is - the book is "Pulse and Digital Circuits" from 1956. I
scanned the Miller and Phantastron sections.

http://www.nixiebunny.com/PhantastronMiller.pdf

[Matthew Smith]

Quoth David Forbes at 2014-02-11 14:38 ...

> Here it is - the book is "Pulse and Digital Circuits" from 1956. I
> scanned the Miller and Phantastron sections.
>
> http://www.nixiebunny.com/PhantastronMiller.pdf

Thank you from me, as well!


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[Tidak Ada]

Hi David,

Found this morning your copy. Looks very interesting.
Many thanks for your efforts.

eric

-----Original Message-----
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Behalf Of David Forbes
Sent: dinsdag 11 februari 2014 5:09
To: neoni...@googlegroups.com
Subject: Re: [neonixie-l] Elesta EZ10/A/B tester refurbished!

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[yen...@internode.on.net]

I seem to remember Morris posting that he had used a Phantastron in something of his?

 

John K. 

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Sent:

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Subject:

Re: [neonixie-l] Elesta EZ10/A/B tester refurbished!

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[yen...@internode.on.net]

I have a few radar books describing theory and actual circuits  - I can scan some if needed too.

 

John K.

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Sent:

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Subject:

RE: [neonixie-l] Elesta EZ10/A/B tester refurbished!

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[threeneurons]

Morris used it in his timebase, as a divide-by-5 stage, and a dekatron, for a total of divide-by-50. That clicked a relay at 1 pps, to increment his stepper relay nixie clock. It was all mounted vertically on a pole, IIRC.

I bought a bunch of 6AS6 pentodes shortly afterward, and ran a few phantastron experiments. For a divider, it works like a one-shot, that needs its cycle to stop just short of the intended time. Say your using 50Hz as your syncing signal, and you want 10Hz out. Setup your RC timing of the phantastron to between no less than 80mS+ (say 81mS), and no more than 100mS- (say 99mS). That is adjust it to between 81 to 99mS. Split the difference, and put it at 90mS. As long as it stays in that range, it will output a sync'd signal at 100mS (10Hz). If you are using 60Hz, instead, then that 80mS+ (4 cycles plus) becomes 87mS+ (5 cycles plus). Keep the divisions small, since they're dependent on the RC component tolerances, and drift factors.

[Tidak Ada]

What do you, mean with small divisions ? Should a devide by 10 be a to great step (from 4Mhz to 400kHz)? 400 kHz should be 'easy' for an EZ10B and is practical formy design...

John,

 

If you think it is usefull information for me, I would be glad with a PDF copy of the pages in question.

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[Grahame Marsh]

The attached is one that I drew in Eagle.  Divide by 10 (from 50Hz) then 5 to get 1Hz.  A copy of published designs. Works very well, easy to tune the two stages to the required factor.  The divide by 5 will divide by 6 as well. 

Grahame

[John Rehwinkel]

> I've built a few dividers down to 1Hz and they work phantastically. Always use the 6AS6 and not just any pentode.

However, Eric said he wanted a low power implementation. Which makes me wonder if any of the subminiature pentodes out there could be pressed into service. Due to the way the rod pentodes work, I think they wouldn't work well. I'm guessing the trick is how G3 causes the current to divide between G2 and the plate. I may have to grab some tubes and breadboard some stuff.

- John

[Grahame Marsh]

The heater power alone can be just a killer.

My (poor) understanding is the design of 6AS6 g3 is as a control grid
proper, like g1. And not there to repel secondary electrons from the
anode. I would guess that a given pentode must just be road tested to
see if it will work - as you say time to breadboard something.

G

[Charles MacDonald]

>>> Always use the 6AS6 and not just any pentode.

> My (poor) understanding is the design of 6AS6 g3 is as a control grid
> proper, like g1.

The 6AS6 Data Sheet from Western Electric says it is for low power
applications at Hugh and Ultra High frequencies (this is from March
1947, so the data sheet is probably not talking about the same Ultra
High frequencies we think of)


The next Line is:
"The usual Control Grid and the suppressor Grid can be used as
independent control elements. The tube is suitable for use in gated
amplifiers, Gain Controlled amplifiers, delay circuits and mixers."

There is a 1949 data sheet that calls it a "Pentode (Dual COntrol)"

Experimentation with other tubes listed as "mixers" or dual control
tubes might be in order, Perhaps colour TV Martix and colour demodulator
types?

[Tidak Ada]

Graham,

Reading some schema's I got in the meanwhile, it looks as the phantastron
isn't able to divide frequencies in the MHz region.
Yours starts at 60 c/s and the HP532A counter from 10 kc/s and below. Is
there any evidence it is possible to divide down from 4MHz to 400 kHz? I am
getting afraid that will be very difficult.

eric

-----Original Message-----
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Behalf Of Grahame Marsh
Sent: dinsdag 11 februari 2014 23:14
To: neoni...@googlegroups.com

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[Tidak Ada]

Afik I have read for short that te 6AS6 was THE tube for pahantastron
circuits.
But may be later there where develoed more tubes with suitable merits.

eric

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[John Rehwinkel]

>>> I've built a few dividers down to 1Hz and they work phantastically. Always use the 6AS6 and not just any pentode.
>> However, Eric said he wanted a low power implementation. Which makes me wonder if any of the subminiature pentodes out there could be pressed into service. Due to the way the rod pentodes work, I think they wouldn't work well. I'm guessing the trick is how G3 causes the current to divide between G2 and the plate. I may have to grab some tubes and breadboard some stuff.
>>

> The heater power alone can be just a killer.

Let's see, a 1AG4 draws 1.25V at 40mA for the heater. That's 50mW. An ordinary dekatron, at 450V and 500µA is 225mW.

Are there any submini pentodes with G3 pinned out separately? Yup, the CK511X is one. More interestingly, the 8522 is listed as a "dual control" pentode,
like a 6AS6, although it draws the usual 6.3V @ 150mA for the heater, same as a 6AS6/5725. The folks on the bay claim a Russian 6J2P is equivalent, I wonder.

- John

[Tidak Ada]

Yes, there are!

But if they are suitable is another question.

1Zh17b
1Zh24b
1Zh29b
1Zh37b

I can serve you with data of these tiny tubes. They are probably developed
for space, missile and airborne fighter.

These are all Russian subminiature tubes of an very uncommon construction.
There are no grids, but rod to regulate the electrons, more or less at the
way of a gammatron, making the system very ruggedized.
Joe Sousa (TCA) has written an article in the Tube Collector and more
extended at the forum of Radiomuseum.org

eric

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[John Rehwinkel]

> Yes, there are!
>
> But if they are suitable is another question.

As I stated before, I'm familiar with these "rod" pentodes, and I doubt they'd work well in phantastron circuits. The electron is a sheet beam, and the rods act as a lense instead of a grid, leading to a very low G2 current. Since the phantastron circuit depends on varying the plate/G2 current split, I don't think they'd be suitable. They're a lovely piece of engineering, and are great for low-noise use (since they don't have grids per se, they have much lower "partition noise" than gridded pentodes).

- John

[Grahame Marsh]

Eric

Going over the material again I have to agree with you. The timing
capacitor reduces in value by 10 for every 10 fold increase in frequency
of course. So at 10kHz it has a value of 47pF (from the pdf I posted)
and below that stray capacitance will dominate. Perhaps the limit would
be a 32768Hz crystal and a series of divide by 8 stages for the
technique but not much higher.

Grahame