trigger tube equivilents

[bob harper]

doing research on this jukebox pcb....a couple of questions please..the GR43's the equivalent has been suggested as Z700U by jan wuesten [german supplier i get obsolete stuff from] but looking at the specs for both on[franks electron tube page] there appears to me to differences in the specs....i am not experienced enough in these devises to know if they will work!

next the ER32 and EA33....the ER33 has actually a GR44 installed in its place [looks original] this a twin start 5 wire device, the specs on franks page...but the ER32 which has been desoldered and removed, i cannot find any info on...its another 5 wire device.

the other tubes i have found o.k and can get replacements, any advice/suggestions on the above gratefully received! thanks, bob

[threeneurons]

Do you happen to have a schematic of that jukebox PCB ? Even though different parts have different specs, might not exclude them. If we can see the circuit its used in, then maybe we can guess at the signal levels, and determine adequate substitutes.

[Nick]

If you need Z700Us and can't find any from Jan etc. let me know - a have a box of them...

Nick

[Dekatron42]

Hi Bob,

 

From the RFT databook och cold cathode tubes I got the information that GR43 is equivalent to GR44, Z70U, Z70W, Z660W and ER33 - possibly with some small changes in component values, but in most cases you can use any of them as a replacement for the other. The ER32 is equivalent to Z70U, ZC1010 and Z661W with possibly the same changes as with the GR43 when it comes to component values. All of these tubes are interchangeable in some form, the limit is usually how much current they can handle in the anode circuit. RFT only made 5-pin versions of their Z660W and Z661W , when they used them to replace the Z70U they just tied the two trigger electrodes together - with the two trigger electrodes used separately they work as the Z70W. According to the datasheet the GR44 is just a later model of the GR43 and works as a replacement without cirucit changes.

 

/Martin

[Nick]

I'm still hunting for XC24s...

Got loads of XC18s for a clock project, but not found any 24s...

Nick

[Dekatron42]

Nick, are you aware of the fact that you can use two XC18's wired in parallel with their anodes and cathodes tied together and with the trigger electrodes separate to emulate an XC24?

 

This trick was shown in old magazines as a way to only use the XC18's in counters where a reset capability was wanted much like when an XC24 was used. There are some other nifty ways of hooking the XC18's up shown in old magazines to build logic gates and such as well as decade counters using fewer than ten XC18's used for frequency division.

 

/Martin

[bob harper]

hi martin, thanks for your detailed reply...from what you say it looks like that they all can be probably replaced with the Z7OOU that jan offered me, with the exception of the 5 wire GR44/ER33 where the triggers are separately connected.....i am waiting for the schematic, once i get it i will post it up, for you experts out there to cast your eye over, before ordering all 10 of them.....thanks to all the help so far....cheers, bob

[NoCampersFluffy]

Martin
Could you post a link to the magazines please.
Kind regards
Michael

[Dekatron42]

Hi Michael,

 

I'm sorry but I don't know of any links to these magazines, I've only found them in old storage places for libraries, there they are glued together year by year and impossible to open and scan since they will break if you open them flat. Sometimes I had a hard time to open them enough to read the inner parts of the pages.

 

All of the articles that I've read are from "Electronic Engineering" from the late 40's to the early 60's. I did some Googling but couldn't find any source right now either.

 

/Martin

[bob harper]

hi all, have now got the schematic, for you experts to look over! also as the power supply is missing, it looks like its a just a isolation transformer at 220v is it worth going for a 240>220? also the original design used a pair of OA2 regulaters, solid state be better and easier? unfortunately the DC voltage is not shown....i have attached the 2 photo's....cheers, bob

[John Rehwinkel]

> hi all, have now got the schematic, for you experts to look over!

Looks like I was wrong, the tube you identified as ER33 really is an ER33 (that's no G on the schematic). Unfortunately, unlike the other tubes, the schematic
doesn't show what the various leads are.

> also as the power supply is missing, it looks like its a just a isolation transformer at 220v is it worth going for a 240>220?

I doubt it, and a 1:1 transformer will likely be easier to find. You can always add another 12-24V transformer wired to "buck" the voltage if you want to drop it a little with common parts.

> also the original design used a pair of OA2 regulaters, solid state be better and easier?

Solid state would be easier (you can get zeners for that voltage). As for better, you have two choices. The 0A2s are actually less noisy than equivalent voltage zeners, however I don't think noise is an issue here (this isn't audio circuitry). You could also use a series regulated supply, which would likely be more efficient (doing away with that 16 watt series resistor) than the existing shunt-regulated version. It would also be quieter, but not easier - a series regulated supply is more complex.

> unfortunately the DC voltage is not shown

A 0A2 regulates at 150 volts, so with two of 'em in series, you'll get 300 volts.

- John

[Dekatron42]

It would be a good idea to use a 240-220V transformer as the transformer supplies the motors and some other stuff with unrectified 220V AC. The transformer also supplies the voltage doubler with the BY104 diodes and 16uF capacitors so you need to check so that those are ok and that they will work with a higher voltage if you don't use a 240-220V transformer.

 

It looks like the ER33 is connected with anode on top, cathode at the bottom, the priming electrode is connected to the 10M resistor and then you have one trigger electrode to the left and one to the right. The circuit with the ER33 seems to be driving a relay (the rectangular box lying down with 10K written inside) means that you might not be able to use any of the similar trigger tubes as they will have a lower anode current which will either not drive the relay or wear the tube out prematurely. You can calculate the current from the resistance values in the circuit and the voltage drop across the ER33 and compare that with other similar trigger tubes. You'll also have to take into account the trigger voltages if you replace it with anything else.

 

The ER33 seems to be connected in a way that it is ignited at power on, from the trigger electrode to the right as that electrode is only connected via a voltage divider and a capacitor that gets its power on pulse from the 300V line. So I guess the ER33 is for resetting at startup and then for resetting at every cycle in the circuit.

 

It looks like your best choice is to find the Z660W or the Z661W and either connect the trigger electrodes together for the ER32 or use them separately for the ER33.

 

/Martin

[Nick]

I had come across the use of paralleled XC18s and experimented a bit - I discussed it with Grahame Marsh some years back when he was doing his trigger clock - I'd still like some *real* XC24s though - paired XC18s don't behave terribly reliably (current obviously doubles when second tube fires)...

There are a lot of XC18, XC24 & Z700U etc. circuits in the standard texts (Dance, Bylander etc.).

Nick

[Dekatron42]

You'll have to set up the XC18's so that only one can be ignited at any moment in your circuit to prevent excess current flowing in the anode resistor, this will be automatically done if you put two of them in parallel in the place of an XC24 in the circuit in the Dance book. The left XC18 (of the pair) which is ignited at power on will be extinguished when the #1 XC18 is ignited, and so it will cycle onwards until #9 is ignited which in turn will bias the right XC18 (of the pair) so that the count starts over at #0.

 

I can fully understand that you want XC24's but for testing the circuit two XC18's works just fine. I've tested it without any problems at all, and also built coupling stages that are self extingushing so that they are not part of the counting ring.

 

/Martin

[bob harper]

hi all, been a while, but back working on this jukebox....am getting there, and have been working on the selection system, checking components and replacing the missing/broken trigger tubes....i have a problem with the ER32 on the schematic [now replaced with Z660W] it is fired by contact K3 closing this a contact which closes and stays closed for the duration of a record playing but the trigger tube only needs to fire a pulse to operate the solenoid which resets the selection pin....it does do this, but then it continues to do this every few seconds...in operation it needs to fire once and then stay off even though K3 remains closed K3 is fed from the AC supply line through the diode...i cant figure out what extinguishes the tube and keeps it off  any help please? thanks, bob

On Sunday, June 16, 2013 12:24:24 PM UTC+1, bob harper wrote:

[Dekatron42]

Did you wire both trigger electrodes together, the Z660W have two trigger electrodes but the ER32 only one.

You must also check that the minimum anode current is 5mA as the Z660W might otherwise work unreliably in some situation according to the datasheet.

You might also have to check the capacitor connected to the anode as well as the anode resistor as those form the circuit that extinguishes the trigger tube, turning it off, and if they do not work properly the tube might not be fully extinguished and then it will turn on again - the capacitor might leaky opr any of the other capacitors/resistors surrounding this trigger tube might be leaky or having the wrong value.

Also don't forget to replace resistors with types that can handle the voltage in these circuits, many cheap resistors sold today only tolerate 125V or 250V which won't do in circuits like these!

/Martin

[bob harper]

hi all...well i have finally got this thing working...all trigger tubes, in the selection system the countdown tubes in the credit unit and the 3 digital display nixie tubes...but ONE remaining problem. the 1st tube on the left in the schematic a GR44 [i have tried another as well] fires when it should, but also when it should not, i disconnected the trigger and it still fires...the problem [i think] is that the K cathode is connected via a wiper contact on a rotating arm to the reset solenoid, which although cleaned and adjusted and tested with the meter, must be occasionally losing its contact [bear in mind the etched track is 50 years old] for a split second...which i am assuming [here my knowledge gets hazy] that would allow the anode voltage to rise and trigger the tube? if this is the case, is there a solution to this? if not, my thought was to put in a relay which when the motor driving the rotating arm is running it opens the circuit from the cathode to the reset coil...any thoughts anyone? thanks, bob

On Sunday, June 16, 2013 12:24:24 PM UTC+1, bob harper wrote:

[JohnK]

Depends on how and where you disconnected the trigger - may need to load down that pin.

Can you confirm that lifting the wiper DOES trigger the tube?   You could set up the right conditions on the other pins [including trigger] and then interrupt that circuit manually.

If it is a 'glitch' from the wiper, a capacitor/resistor network should improve things.

Let's see what is forthcoming from all the others here.

John K

Australia

----- Original Message -----

From: bob harper

To: neoni...@googlegroups.com

Sent: Thursday, March 27, 2014 6:34 PM

Subject: [neonixie-l] Re: trigger tube equivilents

hi all...well i have finally got this thing working...all trigger tubes, in the selection system the countdown tubes in the credit unit and the 3 digital display nixie tubes...but ONE remaining problem. the 1st tube on the left in the schematic a GR44 [i have tried another as well] fires when it should, but also when it should not, i disconnected the trigger and it still fires...the problem [i think] is that the K cathode is connected via a wiper contact on a rotating arm to the reset solenoid, which although cleaned and adjusted and tested with the meter, must be occasionally losing its contact [bear in mind the etched track is 50 years old] for a split second.......clip.....

[bob harper]

Hi right I have broken the circuit to the solenoid from the cathode of the gr44 all other wiring reconnected as schematic it does indeed fire the gr44 and the solenoid if momentary disconnected so that does seem to be the source of the fault. Bob

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[JohnK]

Maybe a capacitor across the wiper contact will solve it. The capacitor would normally be shorted by the wiper making correct contact. A momentary opening would be swamped by the uncharged capacitor. The capacitor may need a small series resistance to reduce the current from the capacitor when the wiper shorts it again. [ I hope - I can't picture the wiper etc that you mention. Want to hear from others too.]

John K.

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[Dekatron42]

Hi Bob,

There is a GR43 for sale on Ebay UK here: http://www.ebay.co.uk/itm/GR43-VALVE-SUB-MINIATURE-GAS-TRIGGER-TUBE-CERBERUS-NEW-OLD-STOCK-/251484552167?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item3a8da5bbe7 , maybe that seller has more if you need.

I am sorry but I don't understand which of the trigger tubes you mean by the "1st tube on the left" - what number is written close to the trigger tube?

/Martin

[bob harper]

hhih

hi martin, yes i am watching the  GR43 on ebay!

yes the 1st tube on the left i was referring to is marked ER32 [sorry thought schematic was posted up] it now has a GR44 installed in place [i have tried a couple] the fault has now been traced to the fact that the cathode connection to the solenoid is via a phenolic track on a pcb with a motor driven wiper arm carrying the connection this if momentarily loses continuity[the track is 50 years old] is enough to fire the GR44 and the solenoid...a capacitor has been suggested across the solenoid, which i have yet to try...bob

[JohnK]

I still haven't looked closely to see what the wiper and track is and where it is on the schematic. That said, my capacitor suggestion wasn't worded that way.

I suggest that the capacitor is wired such that one end is to the wiper arm and the other end is to the track that the wiper arm is supposed to contact. The capacitor is shorted out if everything is normal.  Does your wording mean that too?

Any photos of the track and wiper?

 

John K

Australia

----- Original Message -----

From: bob harper

To: neoni...@googlegroups.com

Sent: Friday, March 28, 2014 8:27 PM

Subject: [neonixie-l] Re: trigger tube equivilents

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[Dekatron42]

Hi Bob,

Thanks for clarifying which trigger tube you meant.

Having looked at the circuit and also at the datasheets for the ER32 and GR44 I think that you will have to adjust the value of the 16uF capacitor and the 150k resistor as they are used for the quenching of the trigger tube, however I don't know how you should change them, but you will have to make sure that you don't lower the 150K resistor too much as that limits the current through the trigger tube. The important thing with the 150k resistor and 16uF capacitor is that they need to have the correct value to make sure that the tube is fully quenched so that it won't re-ignite by itself. You could also try to lower the 22M resistor from the trigger to the common ground to say 10M to see if that helps in keeping the trigger stable.

I think it will be safe to lower the 150k resistor to say 100k and you should also be able to raise the 16uF capacitor to 32uF and even lower it to 8uF without much adverse effect on the trigger tube, but measuring the current in the circuit by hooking up a scope across the 150k resistor to see the peak voltage will give you a good look at what current flows in the circuit - don't forget to use an isolating transformer for the scope so you don't make a ground loop shorting the circuit!

Are you absolutely sure that the circuit diagram is correct around the ER32, there could be something that is not drawn as it is connected in real life.

And photos, as John K says will help a lot in trying to locate faults.

/Martin

[bobhar...@gmail.com]

hi thanks to you and Martin for replies yes meant to say cap across wiper not solenoid

The gr44 does remain stable and will only fire if the trigger pulse is given as long as I don't revolve the wiper arm ,(I temporarily disconnected the drive motor) as soon as I reconnect it and it's revolving at full speed that's when the fault occurs thank bob

Sent from my HTC

----- Reply message -----
From: "JohnK" <yen...@internode.on.net>
To: <neoni...@googlegroups.com>
Subject: [neonixie-l] Re: trigger tube equivilents
Date: Fri, Mar 28, 2014 13:22

I still haven't looked closely to see what the wiper and track is and where it is on the schematic. That said, my capacitor suggestion wasn't worded that way.
I suggest that the capacitor is wired such that one end is to the wiper arm and the other end is to the track that the wiper arm is supposed to contact. The capacitor is shorted out if everything is normal.  Does your wording mean that too?
Any photos of the track and wiper?

John K
Australia
  ----- Original Message ----- 
  From: bob harper 
  To: neoni...@googlegroups.com

 
  Sent: Friday, March 28, 2014 8:27 PM
  Subject: [neonixie-l] Re: trigger tube equivilents


  hhih


  hi martin, yes i am watching the  GR43 on ebay!


  yes the 1st tube on the left i was referring to is marked ER32 [sorry thought schematic was posted up] it now has a GR44 installed in place [i have tried a couple] the fault has now been traced to the fact that the cathode connection to the solenoid is via a phenolic track on a pcb with a motor driven wiper arm carrying the connection this if momentarily loses continuity[the track is 50 years old] is enough to fire the GR44 and the solenoid...a capacitor has been suggested across the solenoid, which i have yet to try...bob
  On Friday, March 28, 2014 9:37:07 AM UTC, Dekatron42 wrote:
    Hi Bob,


    There is a GR43 for sale on Ebay UK here: http://www.ebay.co.uk/itm/GR43-VALVE-SUB-MINIATURE-GAS-TRIGGER-TUBE-CERBERUS-NEW-OLD-STOCK-/251484552167?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item3a8da5bbe7 , maybe that seller has more if you need.


    I am sorry but I don't understand which of the trigger tubes you mean by the "1st tube on the left" - what number is written close to the trigger tube?


    /Martin

    On Thursday, 27 March 2014 09:04:33 UTC+1, bob harper wrote:
      hi all...well i have finally got this thing working...all trigger tubes, in the selection system the countdown tubes in the credit unit and the 3 digital display nixie tubes...but ONE remaining problem. the 1st tube on the left in the schematic a GR44 [i have tried another as well] fires when it should, but also when it should not, i disconnected the trigger and it still fires...the problem [i think] is that the K cathode is connected via a wiper contact on a rotating arm to the reset solenoid, which although cleaned and adjusted and tested with the meter, must be occasionally losing its contact [bear in mind the etched track is 50 years old] for a split second...which i am assuming [here my knowledge gets hazy] that would allow the anode voltage to rise and trigger the tube? if this is the case, is there a solution to this? if not, my thought was to put in a relay which when the motor driving the rotating arm is running it opens the circuit from the cathode to the reset coil...any thoughts anyone? thanks, bob





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[JohnK]

Thanks for the pic of the wiper. 

 I trust the Electrolube brand products -

http://www.electrolube.com/

 

Others swear by a very expensive American cleaner/lubricator. That one has cheap constituants that are marketed cheaply by others but those brands don't have the 'magic' apparently. The chemicals involved were discussed here or Tube Collectors Association group a few times.

 

John K.

----- Original Message -----

From: bobhar...@gmail.com

To: neoni...@googlegroups.com

Sent: Saturday, March 29, 2014 1:34 AM

Subject: Re: [neonixie-l] Re: trigger tube equivilents

hi thanks to you and Martin for replies yes meant to say cap across wiper not solenoid

The gr44 does remain stable and will only fire if the trigger pulse is given as long as I don't revolve the wiper arm ,(I temporarily disconnected the drive motor) as soon as I reconnect it and it's revolving at full speed that's when the fault occurs thank bob

...clip..

[Dekatron42]

Hi Bob,

Would it be possible for you to use a relay in between the wiper contact and the trigger tube? Maybe the wiper could drive a relay and you then use the relay contacts to drive the trigger tube, just for testing if that will solve the problem.

The problem with old SRBP PCB's is that contacts that rotate on them leave a track of dirt which will carry leakage currents. Sometimes you can get rid of this by washing them in an ultrasonic cleaner and also by bathing them in isopropyl alcohol, some need mechanical cleaning to remove the conducting track and some are impossible to clean enough which leaves the only option of letting them control a relay that then controls the original circuit.

/Martin 

[John Rehwinkel]

> The problem with old SRBP PCB's is that contacts that rotate on them leave a track of dirt which will carry leakage currents.

What is "SRBP"?

- John

[Quixotic Nixotic]

Synthetic resin bonded paper.

John

[Nick]

On Friday, 28 March 2014 16:30:04 UTC, Nixcited delighted wrote:
>
> > What is "SRBP"?

> Synthetic resin bonded paper.
>
...aka Paxolin or FR-2

http://en.m.wikipedia.org/wiki/FR-2

Nick

[bob harper]

hi all, thanks for suggestions for this fault.. relay and capacitor tried....it was indeed cured by a capacitor [0.47uf 630v] without the need for a relay.

now i have another question! i am trying to find why GR43 number 15 on the schematic strikes as soon as power is applied and stays lit, until it gets is extinguish pulse, it then after a few seconds re-strikes, it should not strike until it receives a pulse from ER32 tube 8 on the schematic...i have changed capacitors and checked values of resistors around this tube and cant find a fault...is it safe as far as the GR43 to disconnect the trigger and leave it floating, at least then i know if it striking spontaneously or getting a trigger pulse when it should not....thanks, bob

[Quixotic Nixotic]

On 12 Apr 2014, at 21:29, bob harper wrote:

> hi all, thanks for suggestions for this fault.. relay and capacitor tried....it was indeed cured by a capacitor [0.47uf 630v] without the need for a relay.
> now i have another question! i am trying to find why GR43 number 15 on the schematic strikes as soon as power is applied and stays lit, until it gets is extinguish pulse, it then after a few seconds re-strikes, it should not strike until it receives a pulse from ER32 tube 8 on the schematic...i have changed capacitors and checked values of resistors around this tube and cant find a fault...is it safe as far as the GR43 to disconnect the trigger and leave it floating, at least then i know if it striking spontaneously or getting a trigger pulse when it should not....thanks, bob

Hi Bob, good to see you are getting somewhere with the jukebox. It is certainly a unique design. Glad slugging the response with a cap cured the problem. Hope someone can help with the next part of the story.

John