Tokin SIT THF51S curves high tension low current

monotube2

Member
2012-01-13 8:27 am
Here some infos about THF51S curves at low current high tension measured with ROE TEST by Helmut Weigl. More interesting the link in which Helmut analyzes the four samples I sent him

http://www.roehrentest.de/SIT_EN.pdf
 

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monotube2

Member
2012-01-13 8:27 am
very nice information , is there a similar test with the THf51S avalaible with low voltage , high current ? :)



Unfortunately not. ROE test was created to analyze the behavior of the valves, therefore the maximum current is limited to 300ma.
If further tests are positive, my idea would be to create a two-stage hybrid amplifier SE (input transformer, valve maybe DHT, interstage transformer, THF51S, output transformer) using the THF51S high voltage and 200 / 300ma to get 15 / 20 watts. Dave Slagle of Intact Audio has already produced transformers similar to your Tango FG50S and could design "ad hoc" for this need
 
If somebody in the USA has parts, I can perform low voltage high current curve tracing and publish the results.

I'm not sure how many you'd need, but I have a spare (for the moment) pair. I'm not skilled enough to take advantage of the results, but given the generosity of this forum - I could part with them for a while and wait on my build. I used one pair in ZM's SissySIT, and I am extremely pleased to say the least.

I'd be happy to bring them to Burning Amp and/or see if I can mail them.

PM me if that will work for you, and I'll get them your way somehow.
 
I'm not sure how many you'd need, but I have a spare (for the moment) pair. I'm not skilled enough to take advantage of the results, but given the generosity of this forum - I could part with them for a while and wait on my build. I used one pair in ZM's SissySIT, and I am extremely pleased to say the least.

I'd be happy to bring them to Burning Amp and/or see if I can mail them.

PM me if that will work for you, and I'll get them your way somehow.

PM sent
 

Itsmee

Member
Paid Member
2009-02-07 3:00 pm
Thanks for the suggestion, I'll have a look.

So far, no luck with silicone, either too small or sheet that's way too big and expensive. The bigger mica sheet for microwave ovens seems promising, if a little too thick, could split it.
I'm wondering if Kapton tape would work?
 
THF51 curves data

I couldn't find any good curve traces from THF51 out there. Here are mine, maybe they are useful for others. The data are in the ZIP attachment.

I was not sure about the THF51 power / voltage / current limits. If someone could shine some light on this, I might run the traces a bit further into the "hot" area.

For insulators, I use Keratherm/Kerafol, which is available as large sheets from Conrad.
 

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Last edited:
I was not sure about the THF51 power / voltage / current limits. If someone could shine some light on this, I might run the traces a bit further into the "hot" area.

Thank you for sharing the data. The only other information I have was from this thread. It may help. Soundhappy may have more information.

Hockey Puck SIT 2SK180 by Tokin source NOS

Specifically, the graphic in post #32 if the link is not working properly.
 
Perhaps interesting for you - some data and testing done by Helmut Weigl with the TOKIN THF51-S.

I won't impinge upon his copyrights!

http://www.roehrentest.de/SIT_EN.pdf

Yes, I saw those. These data were measured with a curve tracer designed for tubes, so the current range was quite limited. That's why I wanted to get better data at higher currents.

Thank you for sharing the data. The only other information I have was from this thread. It may help. Soundhappy may have more information.

Hockey Puck SIT 2SK180 by Tokin source NOS

Specifically, the graphic in post #32 if the link is not working properly.

THF-51S
Pmax = 400 Watt's
Vmax=600V
Imax=30A
:)

Perfect, thanks! I couldn't take my parts up to 400 W because the heatsink was getting very hot, and I didn't have the guts to take it higher than 200 W (about 90°C heatsink temperature). What is the 150°C spec in the table? Max. heatsink temperature, or max. part temperature? I attached the updated data.

These parts are great! I want to build something with them...
 

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