Revisiting some "old" ideas from 1970's - IPS, OPS

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#881
vzaichenko said:
If you go to Index at the 1-st page and click "NS-OPS", you end up here:
Building instructions

Just note - clockwise / counter-clockwise directions are mentioned there, based on the trimmers orientation at my 1-st prototype version.

Anyway, set the bias spreader to the maximum R position, the clamping spreader trimmer - close to the middle R.

First - you set the bias with no signal. Then - set the clamping with signal.
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Ok thanks ,i got it.
Are the 1N5711 diodes interchangeable with 1N4007?
I'm afraid not🙁
 
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#884
jwilhelm said:
No they aren't. We'll need to get you a few more parts to finish assembling. Please let us know what you are missing. I was short a few parts when I put that together.
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vzaichenko said:
Unfortunately - not really.
1N5711 are the high-speed schottky diodes - high speed is important here.
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So,i will ask a topic supplier tomorrow.
If only the high speed is important,what about BA157,159,BYD33?
 
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#888
AndrewT said:
Would a signal diode like 1n4148 do the "fast" job?
Click to expand...

In fact, 1N4148 is closer to the required parameters, than all the other ones, mentioned by Thimios (those are mostly rectifiers). Capacitance is only twice as much (4pF vs 2pF), recovery time is higher (4-8 nS vs 100pS), but good enough for the purpose - I ran a few simulations.

So, 1N4148 can be used - it will just require re-biasing, as its forward voltage drop is slightly higher. Reserved placeholder within the bias spreader can be used for resistor, adjusting the trimmer's threshold if required.
 
#898
Small progress on power supply board (modifications are just for test).
I'm afraid that is time to desolder some of the power amplifier transistors🙁
I believe that these must be mounted on main heatsink.
To be more clear,Jef i see two points where you type +24v/-24v on power supply board.Is it right? To my point of view this points are connected to main power supply board.
 

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#899
Yes those three transistors mount under the board on the heatsink.

The +/-24V markings are just netports for the rail voltages. The 24V number is just a place holder, not an actual voltage reading. You will see +24V marked in other places on the schematic. These are all connected without actually having a line drawn.
 
#900
jwilhelm said:
Yes those three transistors mount under the board on the heatsink.

The +/-24V markings are just netports for the rail voltages. The 24V number is just a place holder, not an actual voltage reading. You will see +24V marked in other places on the schematic. These are all connected without actually having a line drawn.
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Thanks Jef!
I'm so harry and i must to desolder now.🙁
Is the rectifier board missing too?
 
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