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Old 16th June 2014, 09:41 PM   #1
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Default LaoCao SIT Tests

A couple months ago I received some samples of the SITs from LaoCao in
China which are also being discussed in the thread

V-FET (SIT) amplifier production

I have some results of testing:

Attached are a diagram of the test setup, and the results of distortion vs
output for that setup expressed as output volts and also equivalent output
watts (as if it were driving a power amplifier follower stage).

In this case the bias figures were chosen to null the second harmonic.

Lowering or raising the output DC figure will increase the second harmonic.

The gain without feedback or degeneration is 36 dB, leaving plenty of
margin for feedback.

The output impedance is about 360 ohms.

In this setup the bandwidth is - 3dB at 200 KHz with the input seeing a
total source impedance of 400 ohms.

Attached Images
File Type: gif LCAO SIT TEST.gif (108.1 KB, 527 views)
File Type: gif LCAO SIT DAMP 1.gif (8.4 KB, 516 views)
File Type: gif LCAO SIT DAMP 2.gif (6.5 KB, 508 views)
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Old 16th June 2014, 09:50 PM   #2
Zen Mod is offline Zen Mod  Serbia
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F6-like FE feeding F4-like OS ....... with some serious SE bias ....
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Old 16th June 2014, 11:27 PM   #3
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Pretty neat. Wish those had been around when I did Ironamp.

Thanks, Nelson
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Old 16th June 2014, 11:55 PM   #4
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Quote:
Originally Posted by Zen Mod View Post
F6-like FE feeding F4-like OS ....... with some serious SE bias ....
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Old 17th June 2014, 12:10 AM   #5
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The tube guys really need to see this !

If Kiven is right, we may be able to get these parts before too long.....
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Old 17th June 2014, 12:48 AM   #6
L CAO is offline L CAO  China
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Thanks, Nelson
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Old 17th June 2014, 01:24 AM   #7
lgqliu is offline lgqliu  China
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2.png

3.png
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Old 17th June 2014, 01:30 AM   #8
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> The tube guys really need to see this !

What tube does it emulate best ?
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Old 17th June 2014, 01:37 AM   #9
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Quote:
Originally Posted by L CAO View Post
Thanks, Nelson
No, Thank You.

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Old 17th June 2014, 01:59 AM   #10
kevinkr is offline kevinkr  United States
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Quote:
Originally Posted by hitsware View Post
> The tube guys really need to see this !

What tube does it emulate best ?
Some of us are watching. The curves appear quite triode like, as to what it emulates I can't say.
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