What sockets for tube tester?

jack · Post by **jack** » Mon Dec 31, 2012 4:25 pm

Just built the electronics for a uTester3 from http://www.dos4ever.com - this is an excellent PC/uProcessor based full-function tube tester. Project blog & specs are here: http://dos4ever.com/uTracer3/uTracer3.html.

Now I've got to box this up. I'm thinking small flight case with a whole bunch of sockets...

But which sockets to provide by default?

Ideas please, for old English & US radios, valve amps etc.

What sockets do people actually use & need?

Thanks

pre65 · Post by **pre65** » Mon Dec 31, 2012 4:48 pm

Well, are you only able to fit one ?

B5 was common for British valves and I think B4 will fit B5 sockets as well.

And IO (international Octal) which it seems, is different to Mazda Octal.

Paul Barker · Post by **Paul Barker** » Mon Dec 31, 2012 6:35 pm

kit looks great value. What power of valve can it handle? Any ideas?

jack · Post by **jack** » Mon Dec 31, 2012 7:49 pm

Paul Barker wrote:kit looks great value. What power of valve can it handle? Any ideas?

Specs are on the project page I referenced in the OP. basically, any heater up to 19 volts and 1.5 amps. Any anode or screen from 0 to 300volts. Any grid from 0 to -40 volts. Max power is 65 watts...

So, all types of tubes including multiple triodes, magic eyes, pentodes etc..

Its a very very good bit of kit. Extremely clever design - should be too as Ronald Dekker is a professor of electronics and senior researcher with Philips. The blog is an excellent read too...

I'm really enjoying building this...

James · Post by **James** » Mon Dec 31, 2012 8:06 pm

Hi Nick,

Based on your tip off earlier in the year (thanks!), I too have just completed one of these as a Christmas present to myself.

Like you say, a fantastic bit of kit.

I too have been pondering the socket and switching arrangement and snapped up one of these to aid the switching between socket/pin configurations.

http://www.hificollective.co.uk/catalog ... -9206.html

I will post my configuration once I get it finalised.

Happy new year to all!

Best Regards

James

Paul Barker · Post by **Paul Barker** » Mon Dec 31, 2012 9:18 pm

Seems too good to be true.

I daren't spend the money on one but looking forward to some screen shots of when you guys play with these new toys.

Greg · Post by **Greg** » Tue Jan 01, 2013 2:34 am

Way-hey James, Happy New Year to you and Trudy. Nice to know my local mate has a valve tester

I'm surprised the kit doesn't come with recommendations on valve sockets and switches. The original finished build seems to have a choice of 9 sockets.

Greg · Post by **Greg** » Tue Jan 01, 2013 2:34 am

Double post deleted.

jack · Post by **jack** » Tue Jan 01, 2013 10:02 am

Greg wrote:...I'm surprised the kit doesn't come with recommendations on valve sockets and switches. The original finished build seems to have a choice of 9 sockets.

That's not really the point of it - the s/w & h/w can test & measure a large range of tube types - the sockets are "secondary" - just interfaces, and you can have as many different types of those as you wish.

It'd be great to have every socket type - say 25? - but that'd be a wiring nightmare. Best to be reasonably selective for those sockets permanently wired, and to use an octal->whatever adapter for those others odd ones.

The main problem to avoid is parasitic oscillation in the socket wiring, so its done like the AVOs - as loops with lots & lots of ferrite beads...

pre65 · Post by **pre65** » Tue Jan 01, 2013 3:16 pm

This here tube tester, does it just test valves, or can it be used to plot the characteristics ?

I ask because I'm using a twin tetrode as parallel single ended and with positive grid bias and there is no published information.

Mike H · Post by **Mike H** » Tue Jan 01, 2013 3:31 pm

It's web page(s) says it works along with a Windows program that makes the plots, so apparently yes. Will need RS232 serial interface port though to connect PC to the board.

Post by **Nick** » Tue Jan 01, 2013 3:44 pm

pre65 wrote:This here tube tester, does it just test valves, or can it be used to plot the characteristics ?

I ask because I'm using a twin tetrode as parallel single ended and with positive grid bias and there is no published information.

Given power supplies and meters you can plot your own curves.

Does the tracer handle +ve grid voltages and current? Would be great if it does?

James · Post by **James** » Tue Jan 01, 2013 4:50 pm

Paul Barker wrote:Seems too good to be true.

I daren't spend the money on one but looking forward to some screen shots of when you guys play with these new toys.

Hi Paul

Here's a couple of pictures of the tracer in action with a KT66.

The tracer cannot handle positive grid voltages, the hardware generates negative bias voltages only.

Best Regards,

James.

Post by **Nick** » Tue Jan 01, 2013 5:06 pm

Looks like a great bit of kit.

Paul Barker · Post by **Paul Barker** » Tue Jan 01, 2013 5:16 pm

Excellent. Sadly Vade Mecum only gives curves for 250v as the lowest G2.

It does say that at 200v g2 and zero g1 bias there would be 160mA whereas at 250v it would be another 50mA so 20 to 30% greater current per grid voltage.

So my 250v g2 curves would suggest at 300v -10v 120mA your findings at 200v a tad under 90mA, application of difference shown formerly would extrapolate 92mA so your valve looks right on the button.

I like the idea of using the relay base for simplicity and flexibility.

One could just make valve pin holes in Teflon push valve through and attach lebelled clip leeds for the other types, and have a relay base for octals.

I am wanting one now! WOW!!!!

audio-talk

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