SissySIT

beginning of the work .... populating the pcb...

the 2SK180 are waiting ..... on the pcb they can not be soldered:ill:
 

Attachments

  • 20181111_004659.jpg
    20181111_004659.jpg
    229.3 KB · Views: 677
  • 20181111_011354.jpg
    20181111_011354.jpg
    172.4 KB · Views: 689
Official Court Jester
Joined 2003
Paid Member
open these red jumpers , if you didn't already set buffers

do you know Ugs for your 2SK180 , for Iq in range of 1A8-2A ?

of course that you need to find a way of mounting 2SK180 - use piece of L bracket , no lesser thickness than 5mm

take care that "flying" gate resistor is near gate pin of 2SK180 ; good practice is to heatshrink it with wire , that way it's sturdier
 
open these red jumpers , if you didn't already set buffers
naturally......you explained it clear...but...I do not want to miss the jumpers .... I left them for this

do you know Ugs for your 2SK180 , for Iq in range of 1A8-2A ?
no.....but maybe I can find it in the documentation I have

of course that you need to find a way of mounting 2SK180 - use piece of L bracket , no lesser thickness than 5mm
I already have a 4mm L bracket available.

take care that "flying" gate resistor is near gate pin of 2SK180 ; good practice is to heatshrink it with wire , that way it's sturdier
good practice
thanks a lot ZM...my master:)
 
Last edited:
characteristic curves obtained from Jama instrumentally supplied by SIT in attach.

In any case if you can give me a link where I can find the correct procedure I thank you ..... but I ask you: how should I then do the calibration?
 

Attachments

  • 20180102_124639_resized-1.jpg
    20180102_124639_resized-1.jpg
    283.5 KB · Views: 590
  • 20180102_124644_resized.jpg
    20180102_124644_resized.jpg
    252.5 KB · Views: 568
i saw D1+D2 being stuffed on your boards, and I remember them as leftouts in the Sissy circuit,
but wait for the Pros to respond on this, I´m troublemaker chicken : )

"..... but I ask you: how should I then do the calibration?"

you don´t do calibration, it´s just for veryfying that Sit is within (optocoupler?) window
 
Last edited:
Official Court Jester
Joined 2003
Paid Member
characteristic curves obtained from Jama instrumentally supplied by SIT in attach.

In any case if you can give me a link where I can find the correct procedure I thank you ..... but I ask you: how should I then do the calibration?


according to these graphs , so I understood they're exact measurements of your specimens , it seems that they're in region of -3 to -3V5 for our range of voltage and currents

so , just go for it

regarding surplus diodes - just cut their pins
 
in practise you cut negative wire from PSU, put 0,1R in between, there you measure across 180 to 200mV. But starting cold set it no higher than approx 150mV, it will rise significantly over half an hour so so. After Iq being stable do fine adjustment for offset.
(maybe all was clear to you : ), doesn´t hurt to write again, anyway)

Iq pot for beginning set as in schematic!
 
Member
Joined 2007
Paid Member
I have currently an F4 with CRC PSU with 8x27000u/50 Panasonic 105º TSHA
I intend to use this for my Sissy Sit but with dual mono operation with 2 250VA trannies and new psu boards.
I would buy more of the same caps but AFAIK they are no longer being available.
Assume I should I spread the caps over all 4 new boards and add something similar in remaining two 'slots' per board . I believe they are good caps. What would be a good match for optimum SQ? I could try to match specs but welcome any recommendations.
I imagine with dual 250VA supplies the 27mF caps are more of an overkill and I could add somewhat smaller capacity items.
 
Last edited: