+ Reply to Thread
Page 3 of 6 FirstFirst 12345 ... LastLast
Results 21 to 30 of 53

Thread: DIY valve tester.

  1. #21
    Join Date: Aug 2013

    Location: London

    Posts: 1,499
    I'm Sam.

    Default

    How about this one from Lampizator?


    Oh I forgot to draw the pot. It connects between the AAA cell stack - negative and the ground. The viper goes to tube grid. We also need interrupting switch because the pot (100K or 50K) will discharge the cells.

    Of course instead of cells we can build own electronic supply of variable voltage from minus 5V DC to 0V.
    Err, stick a plastic box over it when in use for safety!

    http://lampizator.eu/UPGRADE/tubetes...%20tester.html

  2. #22
    Join Date: Apr 2012

    Location: United Kingdom

    Posts: 2,302
    I'm Richard.

    Default

    Quote Originally Posted by Audio Advent View Post
    How about this one from Lampizator?




    Err, stick a plastic box over it when in use for safety!

    http://lampizator.eu/UPGRADE/tubetes...%20tester.html
    Er, yes, I've seen that, but it didn't get my juices flowing. And I would like something I could actually move safely! I may one day Lampizate my Squeezebox Duet, that wouldn't move.
    ABD.

  3. #23
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,173
    I'm Jez.

    Default

    They are both rather simple and limited... especially the second one!

  4. #24
    Join Date: Apr 2012

    Location: United Kingdom

    Posts: 2,302
    I'm Richard.

    Default

    Ah, well so am I, so the one I'm making should be ideal. I just need to test the old valves I have, and I have lots of the bits already.
    ABD.

  5. #25
    Join Date: Oct 2009

    Location: Birmingham, UK

    Posts: 394
    I'm Phil.

    Default

    nice cheap English new colvern 10k pot for the bias voltage adjustment

    (http://www.ebay.co.uk/itm/Poti-Wider...IAAOSwaNBUcGkp


    There seems to be two versions of this tester , but the b9a socket will test everything I have , will you be buying the transformer he has listed , me phil.
    Phil.

  6. #26
    Join Date: Aug 2013

    Location: London

    Posts: 1,499
    I'm Sam.

    Default

    Quote Originally Posted by awkwardbydesign View Post
    Er, yes, I've seen that, but it didn't get my juices flowing. And I would like something I could actually move safely! I may one day Lampizate my Squeezebox Duet, that wouldn't move.
    Doesn't mean you have to make it exactly like that on a piece of board! If I'd only shown the circuit diagram then the thought of safety wouldn't have entered your mind.

    What if the one you're thinking about had been mounted on a piece of wood would you reject that?

    The Lampizator has the advantage of being simpler and not needing a second power supply for the .... err whatever the batteries are for. AND what I like about Lampizator is that he does things in his very "it's so simple! Just do it like this on a piece of board and stop fussing and putting up barriers about having a case and everything being OCD perfect.. Just do it!" attitude. That appeals to me.

  7. #27
    Join Date: Aug 2013

    Location: London

    Posts: 1,499
    I'm Sam.

    Default

    Quote Originally Posted by Arkless Electronics View Post
    They are both rather simple and limited... especially the second one!
    Depends what you want it for I guess. Simple checking if the valves are ok and halves matched is probably all most are looking for for tube rolling.

  8. #28
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,173
    I'm Jez.

    Default

    Quote Originally Posted by Audio Advent View Post
    Depends what you want it for I guess. Simple checking if the valves are ok and halves matched is probably all most are looking for for tube rolling.
    Better than nowt but I'd want it to go up to 800V+ for power valves. Not much point testing a KT88 at 250V max.

  9. #29
    Join Date: Apr 2012

    Location: United Kingdom

    Posts: 2,302
    I'm Richard.

    Default

    Quote Originally Posted by oceanobsession View Post
    nice cheap English new colvern 10k pot for the bias voltage adjustment

    (http://www.ebay.co.uk/itm/Poti-Wider...IAAOSwaNBUcGkp


    There seems to be two versions of this tester , but the b9a socket will test everything I have , will you be buying the transformer he has listed , me phil.
    I'm getting a cheap carbon pot from RS. Is that Colvern wirewound? I have a couple of transformers, one 6v and one 15v x 2. The trafo he lists appears to be available only in Australia. Cheap enough to buy, but expensive to post! It would have been cheaper to buy this pair on ebay. http://www.ebay.co.uk/itm/3811099387...%3AMEBIDX%3AIT and http://www.ebay.co.uk/itm/15VA-2-x-6...YAAOSwr81UPXJa
    ABD.

  10. #30
    Join Date: Apr 2012

    Location: United Kingdom

    Posts: 2,302
    I'm Richard.

    Default

    Quote Originally Posted by Audio Advent View Post
    Doesn't mean you have to make it exactly like that on a piece of board! If I'd only shown the circuit diagram then the thought of safety wouldn't have entered your mind.

    What if the one you're thinking about had been mounted on a piece of wood would you reject that?

    The Lampizator has the advantage of being simpler and not needing a second power supply for the .... err whatever the batteries are for. AND what I like about Lampizator is that he does things in his very "it's so simple! Just do it like this on a piece of board and stop fussing and putting up barriers about having a case and everything being OCD perfect.. Just do it!" attitude. That appeals to me.
    Negative bias on the grid?

    Quote Originally Posted by Audio Advent View Post
    Depends what you want it for I guess. Simple checking if the valves are ok and halves matched is probably all most are looking for for tube rolling.
    Quote Originally Posted by Arkless Electronics View Post
    Better than nowt but I'd want it to go up to 800V+ for power valves. Not much point testing a KT88 at 250V max.
    Lukas' circuit is too basic for me. I think he threw it together in about an hour from bits he had in his pocket!
    And testing what I have is the main reason for building the tester, plus the design AND layout have been tested, it seems. Also I have most of the "expensive" bits. Just not a suitable baking tray.
    If I start getting fussy, I would want to test 845 DHTs too, as I have a couple left over.
    ABD.

+ Reply to Thread
Page 3 of 6 FirstFirst 12345 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •