[jostber]

The new VacuTrace seems like a great solution for tube testing and matching. Can it handle 211's as well?

http://www.haglabs.com/vacutrace.html

[hagtech]

Not directly, no.  You would need to insert an external heater supply (center-tapped 10V secondary of filament transformer).  I've done this before with big tubes.  You can sweep curves, but the operating area is quite small and it won't get you close to a normal operating point.  The VACUTRACE will max out about 400V and 200mA.  And it only drives the grid negative.  That's not going to tell you a whole lot about a big transmitter tube. 

On the other hand, if matching tubes like 6550 or 300B, if they match well at low currents and the curves lie on top of each other, they will likely be matched at high currents too.

jh

[jostber]

Thanks. Do you know what's the most used equipment to test and match 211's?

[jostber]

Or will you build a special edition for this? Somewhat like the Amplitrex with the 211 adapter?

[hagtech]

I was not planning on making a 211 adapter.   And you're the first to ask for it.  How does one test this tube now?  I don't know, probably some custom equipment.  In order to test this tube properly you need lots of grid voltage, both positive and negative.

Oddly, I was unaware of the Amplitrex.  I just googled it.  Interesting.  These are not easy machines to make!

jh

[jostber]

Here is the Amplitrex 211 adapter:

http://www.amplitrex.com/adapters.html

Of the vintage testers the EMC pops up most often during search:

http://www.worthpoint.com/worthopedia/electronic-emc-model-211-tube-tester-w-manual

And some use the Hickok:

http://jimmyauw.com/wp-content/uploads/2010/01/hickok-539b.jpg

This fella built it himself:

http://www.houseofficer.com/tubetester.html

[jostber]

More on testing with the Amplitrex:

http://psvanetube.com/wordpress/psvane-tubes-gf-test-method/