Nisbeth, thank you for your quick answer.
Since you live within the European tax-union, shipping will not cost too much.
I will give you the price of the PCBs incl. shipping via PM.
Moreover: I will give you the documentation, the BoM (I even have a complete (more or less) "shopping cart" for the FC-100 components,
saved at "www.reichelt.de", drill-master, ...
We can talk about hard to get components, matching, ..., if you like.
Best regards - Rudi
Since you live within the European tax-union, shipping will not cost too much.
I will give you the price of the PCBs incl. shipping via PM.
Moreover: I will give you the documentation, the BoM (I even have a complete (more or less) "shopping cart" for the FC-100 components,
saved at "www.reichelt.de", drill-master, ...
We can talk about hard to get components, matching, ..., if you like.
Best regards - Rudi
Does anyone have a copy of the FC-100 builder's manual pdf?
I need to check the bias as
I have some issues with the amplifier.
It seems the bias is rising slowly with temperature and becoming unstable.
The 4A (F2) fuse keeps blowing if the amp gets hot.
I need to check the bias as
I have some issues with the amplifier.
It seems the bias is rising slowly with temperature and becoming unstable.
The 4A (F2) fuse keeps blowing if the amp gets hot.
Patriz, do you mean the issue described by Rudi in his builder's manual?
He solved the problem by disabling ThermalTrak diode and bypassing it with a BAT42 Schottky diode.
I'm not sure which diode should be bypassed. Rudi bypassed the second (Q2 transistor).
Also, in the datasheet of the BAT42 I can see the max forward voltage is 400-650 mV. Should it be lower @ 0.2-0.3 V?
He solved the problem by disabling ThermalTrak diode and bypassing it with a BAT42 Schottky diode.
I'm not sure which diode should be bypassed. Rudi bypassed the second (Q2 transistor).
Also, in the datasheet of the BAT42 I can see the max forward voltage is 400-650 mV. Should it be lower @ 0.2-0.3 V?
I installed the Bat42 diode but it didn't solve the problem. I bought another set of TT I installed the TT in a non definitive way until I found the right combination. Now is working without the Bat42. I bypassed the diode that gave me the best matching. It could be T2 I don't remember
I tested the amp again and when I power it on the voltage drop across each of the 2 emitter resistors is 38mV and then slowly doping down. After a few minutes it is 36mV and continue to drop 0.01 mV per second (from 36mV to 35.4mV in a minute).
Is this normal?
Rudi suggested checking and adjusting the bias after 15-30 minutes. Does it mean I should adjust to get 36-38mV when the amp is hot?
Once the amp is cooled down and powered back on the voltage is something about 44mV.
Is this normal?
Rudi suggested checking and adjusting the bias after 15-30 minutes. Does it mean I should adjust to get 36-38mV when the amp is hot?
Once the amp is cooled down and powered back on the voltage is something about 44mV.