Live Lab Hangout #1.1 Posted

[jama]

I have increase voltage in PS to 63Vdc. Now current increase to 1.9A with 3.6V of polarization voltage. Well, now into 8 ohm I have 1A of current and 7Vrms (6watt into 8 ohm).

 

[Michael Rothacher]

Go jama! 🙂

 

[jama]

Thank you Michael. You are our inspiration....thanks to you.
The photos are input and output together, output with 20Khz square wave, harmonics to sine wave and all together.
The next step is change number of bulbs. Transistor are not hot. I think is possible increase current ...

 

[Bones13]

Stellar work. I received a box of 182ES this week, and watching with anticipation. Keep up the good work.

 

[jama]

Good days all. Today I have add second bulb 500W 150V. Well. Output power increase until 10W rms. My laboratory power supply is full and output voltage low to 53Vdc, but with PS with transformer and caps sure we can reach a little more output power. Sit now is a little more hot, but with a good heatsink not a problem (voltage across sit is 9.5 Vrms and current is 3.2A).

 

[cwtim01]

... Output power increase until 10W rms ...

Congratulation on your great work.

Could you also post the spectrum at 1W output. From your spectrum picture @10W, it seems THD is around 9%, and I would be very interested to have an idea of the THD @1W.

 

[jama]

@cwtim01
I can not measure % low distortion, only can see FFT of my scope. With 1Wrms 8ohm I can not see harmonics (not possible I know).

 

[jama]

When I use trafo and caps (two units of 48V 3A in parallel and 4 x 37000uf/75V) , I have 65VDC and current (with 3.77V of polarization) is 3.57A. Now output power increase to 12Wrms to 8ohm.

 

[cwtim01]

@cwtim01
I can not measure % low distortion, only can see FFT of my scope. With 1Wrms 8ohm I can not see harmonics (not possible I know).

Thanks, THD must be pretty low @1W then 🙂

 

[jama]

But now heatsink of sit are hot. I can touch more of 5 seconds by hand (21.2V across drain and source pins = 21.2 x 3.6 = 76 watt!!!!!!)

 

[jama]

This is how 20kHZ square wave appear at output at full power... Square wave at input is ugly, but it is the same at output !!!.
My wave generator is not very good...

 

[Soundhappy]

....but it is the same at output !!!.

Clearly goood IT 😀

 

[jama]

Now I want to see what happen with 16 ohm speaker....

@Soundhappy. It is very funny mount this amp...

 

[Soundhappy]

@ Jama
I am glad you have good time 🙂
@ Diyers
Last news 2015 and research history
from Tokin & Sony static inductor transistors inventor

http://thz.caltech.edu/siegelpapers/THz_Pioneer_Jun-ichi_Nishizawa.pdf

long life Jun-Ichi Nishizawa San

 

[cwtim01]

Another data point, the curves are spaced by 0.25V apart.

Eagerly waiting for Hangout #5 🙂

 

[Soundhappy]

Eagerly waiting for Hangout #5 🙂

@cwtim01

My too 😀

And study

http://www.eng.auburn.edu/~wilambm/pap/2007/SID_Wilam.pdf

Your curve tracer are handy tool 🙂

 

[cwtim01]

... And study

http://www.eng.auburn.edu/~wilambm/pap/2007/SID_Wilam.pdf ...

You're really resourceful with SITs 🙂

 

[Michael Rothacher]

I can confirm that at least some of eyelabo_jp's stock have curves like the bad parts I've posted. He does not have the means to test this, but he does offer a 14 day return on his Ebay auctions. I recently had to return a batch of 180's and I'll let you know how it works out.

I would suggest, that unless you are able to test these parts upon receipt that you exercise caution in your purchases, which of course, is always the case when buying these old transistors.

 

[Soundhappy]

....is always the case when buying these old transistors.

Hello Michael

How many of 2SK180 or 182ES was not working ones
from your batch if we can speak % ??
Best regards

 

[Michael Rothacher]

None of the 180's were good. They all had to go back.