Mullard HSVT - Gate Switch Hole Calculator & Editable Card Templates?

[Chris55000]

Hi!

Just a quickie one with a few questions on the Mullard HSVT!

1) Was there ever any form of Excel or similar calculator written that allows you to input the thermionic valve data from a valve datasheet that automatically calculates which holes to punch in the card?

2) Also is there an editable HSVT Card Template that you can fill in your own valve type nos., etc., on?

3) Can anyone recommend a cheap and easy method of making cards? I have a Tek 545A that uses some obscure valves that may not have a ready-made card available!

4) Will the HSVT test neon and gas voltage-regulator tubes, and if so, what indication do you look for?

Chris Williams

[David Simpson]

Chris, I might be pointing out the obvious - but why don't you delve through the massive HSVT Card thread, (At the top of this sub-forum opening page), raised years ago by GMB? It seems to me that every aspect of card manufacture & replacement, etc. can be studied at great depth. Folk are still adding to it, even now.
If you're desperate to get your TEK 545A's obscure valves tested, let us know the makes & numbers. If you're unable to get them tested on conventional valve testers, perhaps myself & a few other guys who have built specialist homebrew DC valve testers, could help.

Regards, David

[Chris55000]

Afternoon Dave!

I'll have another read of that - I must have missed some of it out somehow!

I've got some binders and coloured Index Cards - me thinks I would do well to print off a set of the manuals & things as well as GMB's thread pages on the HSVT to archive 'em in - I am thinking about one of these in the summer once my holliers are paid for - this is why I asked the questions!

Chris Williams

[Electronpusher0]

I started an Excel file to define the function of each hole on the card, determined by analysis of the schematic.
Very much work in progress but it may be useful.

Peter

[Ed_Dinning]

Hi Peter, a useful spreadsheet there. I look forward to seeing the completed one.

Ed

[PJL]

I did this some time ago in conjunction with GMB with a plan to incorporate his final version of the cards list. Seeing as that was back in 2006, it seems a waste not to share it. The program is written in JavaScript and will run on a browser, IE just asks you to accept the security risk but Chrome requires you to enable access to local files before it will run the JavaScript. It calculates the test conditions and, assuming your tester is working to specification, will allow you to interpret the deflection on the screen which is near enough linear. You can also make your own 'cards' by clicking on the holes and then see the corresponding test conditions. There is some documentation included but it is so long ago I really can't remember how much. I did check the results on my restored tester at the time but as per the warnings in the documentation...no guarantee and at your own risk. The calculations are not simple and involve emulating a triode!

[Electronpusher0]

Thanks so much PJL!
I will enjoy testing it out.

Peter

[Chris55000]

Hi!

. . .And from me also!

Chris Williams

[PJL]

Let us know how you get on

[Chris55000]

Hi!

Sorry to be a pain in the proverbial - I'm not sure exactly you get those two *.js files to run on Chrome - all I get on clicking them is a brief flash of a cmd box which then closes - should some sort of graphical dialogue box appear?

I tried using IE but that didn't do anything - is there a database or additional file needed or does the two js files contain everything?

Opening up the "example.js" in Chrome produces a listing of enormous length, mostly rows of '@' signs!

If anyone can enlighten me as to the workings of this I'd be very grateful - I've just joined the party with an E7600/3 that I'm collecting Bank Holiday Monday!

Chris Williams

PS!

I'm hoping the one I'm getting will have card 635 (EL84) in it - I have 8 Russian ones (6П14P) to test it with (after full servicing!) and I'll ne wanting to know if Mullard punched H9 instead of H8 in mine!

[Electronpusher0]

Originally Posted by Chris55000

I'm hoping the one I'm getting will have card 635 (EL84) in it - I have 8 Russian ones (6П14P) to test it with (after full servicing!) and I'll ne wanting to know if Mullard punched H9 instead of H8 in mine!

Hi Chris,
I guess you are referring to my post about card 635 being (possibly) wrong in this thread:
https://www.vintage-radio.net/forum/...=148550&page=2
I have tested all my EL84s since then and I remain convinced that the original card is indeed wrong and will show all EL84s as low emission, still probably in the bottom of the green band, but low.

If you find your card is "wrong" send me a PM and I can punch a new one for you for £3 (to cover the cost of the material and postage).
It will be in white as per the photo in the above linked thread.

Regards
Peter

[Electronpusher0]

Originally Posted by Chris55000

I've just joined the party with an E7600/3 that I'm collecting Bank Holiday Monday!

Hello again Chris,
Just noticed the text quoted below.
Unless the HSVT you are collecting is known working DO NOT JUST SWITCH IT ON you risk doing a lot of damage.

The high voltage capacitors will need reforming at the very least, the electrolytics in mine reformed but I ended up changing them anyway. The 4uf electrolytics in the high voltage supply would not reform and had to be replaced. The EY51 rectifiers and the EF50 also needed replacing.

If you need any further information check the previous threads on this forum, I found them very helpful. (and you can always ask here)

Peter

[PJL]

Originally Posted by Chris55000

Hi!

Sorry to be a pain in the proverbial - I'm not sure exactly you get those two *.js files to run on Chrome - all I get on clicking them is a brief flash of a cmd box which then closes - should some sort of graphical dialogue box appear?

I tried using IE but that didn't do anything - is there a database or additional file needed or does the two js files contain everything?

Opening up the "example.js" in Chrome produces a listing of enormous length, mostly rows of '@' signs!

If anyone can enlighten me as to the workings of this I'd be very grateful - I've just joined the party with an E7600/3 that I'm collecting Bank Holiday Monday!

Chris Williams

PS!

I'm hoping the one I'm getting will have card 635 (EL84) in it - I have 8 Russian ones (6П14P) to test it with (after full servicing!) and I'll ne wanting to know if Mullard punched H9 instead of H8 in mine!

Hi, if you are referring to my application. I messed up and have attached a new zip file here with ALL the files.

Even then you would need to use IE as I am still having problems persuading Chrome to access local files.

1. Download the zip file and copy to a location where you want to install the program
2. Click on the file to Unzip, it should open the folder automatically
3. Right-click on MHSVTCalculator.html and select 'Open with' and choose Internet Exporer.
4. Press on security button to 'Allow Blocked Content'.
5. Enter CARD No. and press Find

Example printout attached

[Chris55000]

Hi!

Member PJL, thank you very much for that!

With regards to the instrument I'm getting, I was given a large quantity of the modern high–voltage yellow polyester capacitors, 400V and 630V, these will be fitted to my instrument before powering up and a full rebuild of all the resistors will be carried out!

One question tho', it is safe to test between the windings of the mains transformer (with each winding pins connected together) using a modern solid–state insulation tester, and what would be the safest recommended test voltage?

(I am aware leakage on the high h.t. winding to earth/core or the LT windings, etc., can occur with these transformers, causing calibration and stability difficulties!)

I think it's the E7600/3 I won so hopefully it's the improved transformer!

[PJL]

Lots of out of tolerance resistors are the main problem with these. The high stability close tolerance ones survive OK but I ended up replacing most of the rest. There are a pair of electrolytics in the EHT that are also a priority. Beware of leaving the power on as it leaves the heaters running and wrecks the expensive EL37.

[PJL]

I spent a little time looking at Chrome and it appears that you can't use a form on a local file even after you have enabled local file access. I did find a few hits when looking for a solution but I suggest you use IE if you can.

[Ed_Dinning]

Hi Chris, possibly worth the EHT transformer trick of running low voltage DC through the mains pri and gently warming the transformer for several days to drive our any moisture.

These are a total pain to rewind.

I suspect the the original transformer would have been flash tested at 2KV. It may be wise to restrict this to 1KV for an old unit

Ed

[Chris55000]

Morning Ed!

I can easily remove the transformers and run them at low voltage current–limited. D.C . from a current–limited lab psu and I've access to a heated drying cupboard at work, and I think my work's insulation tester is 1000V max, if the insulation tests ok @ that voltage, hopefully there won't be too many wandering spot issues!

Chris Williams