Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: Ed_Chambley on September 05, 2017, 07:02:45 pm
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Hey guys, did a forum search and I cannot find a discuaaion on making a tube tester. I have a hickock 6000A, which is a good tester, but I recall someone mentioning a few years ago about either making or a design for a tester that would test tubes under operating voltages.
I would like to add one, but of course I do not need to test a large variety. I would like to test 9 pin and octals. For the power tubes, testing at 500 vDc wuld be nice, but most commercial testers are only 400 VDC. I really do not know why so input is appreciated.Up to 300 for small tubes would be nice. Of course, I do prefer adjustable.
I wish to match power tubes and check balance in dual bottles. If anyone has a schematic/layout and method, if you have the desire to share it would be appreciated.
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Build a Champ, two sockets at each location. Bring key points out to meter-holes.
Run known-good tubes through it. All good 12AX7 will be around 150V-200V at plate. 6SL7 will run a bit lower. All good 12AU7 or 6SN7 somewhat lower. If a ??? tube doesn't read like others, doubt it.
EL84 wants a smaller Rk than 6V6 6L6 for maximum output. But EL84 will work with 6V6 values, just make a note of what an average good EL84 reads.
Also feed guitar and speaker. 12AU7 needs more strum-power than 12AX7 but it will play OK. A tube may come to nominal DC values but rattle or hiss or buzz or ring like a bell. Such non-test problems may be more important than finding exactly 1,600uMho @ 1.5mA.
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Maybe this will float your boat: http://triodeel.com/tester.htm (http://triodeel.com/tester.htm)
Though it sure makes PRR's suggestion seem attractive, which also let's you listen to a tube to check for microphonics, e.g.
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thank to both of you. Good stuff.
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this one gets good reviews...
http://www.dos4ever.com/uTracer3/uTracer3_pag0.html (http://www.dos4ever.com/uTracer3/uTracer3_pag0.html)
--pete
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Thanks DL. Just a quick review of this has thrown me a curve. Some of the builds housing the board are first rate, but they also show basic approaches.
Again, good stuff.
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i would add automation: select from a menu and relays to configure the appropriate connections to the appropriate socket. IF i were to build one. and...IF i wanted a modern tester, i'd just probably just buy an amplitrex.
http://amplitrex.com/ (http://amplitrex.com/)
they're asking price is not unreasonable for what it does and is in-line for a decent piece of test gear, just don't need that level of testing. no one really does unless you're a distributor or an obsessed hi-fi nut.
i'm with PRR, just need to build the champ "test" fixture... :icon_biggrin:
--pete
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What is that 'not unreasonable' price? I don't see one on that site?
~Phil
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What is that 'not unreasonable' price? I don't see one on that site?
~Phil
2.9k
--pete
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this one gets good reviews...
http://www.dos4ever.com/uTracer3/uTracer3_pag0.html (http://www.dos4ever.com/uTracer3/uTracer3_pag0.html)
--pete
I have build this thing and a friend of mine did too. Works like a charm.
It has a bit of a learning curve adjusting measurement parameters in the accompanied windows software, but it is well documented on Ronald Dekker's site