faggianfra
New Member
Hi all,
I have a problem with my oscilloscope Leader LBO 518, I found already the problem in my ch1 vertical preamplifier circuit and I resolve it to exchange the dual fet (q23a and B 2n30809 in the schematic attached) with this for ch2.Now , the problem is: I'm not able to find the obsolete dual fet or any documentation about it.
I tried to put two normal fet but with no success.
I found some dual fet on the market, but the price of them is pretty high, so just to buy some of them for testing it will cost me the price of the scope.
Are there anybody thet could help me to find a solution to make it, or any idea how i can
polarize the fet to have the same function of the dual one, or give me some explication how is working?
I have a problem with my oscilloscope Leader LBO 518, I found already the problem in my ch1 vertical preamplifier circuit and I resolve it to exchange the dual fet (q23a and B 2n30809 in the schematic attached) with this for ch2.Now , the problem is: I'm not able to find the obsolete dual fet or any documentation about it.
I tried to put two normal fet but with no success.
I found some dual fet on the market, but the price of them is pretty high, so just to buy some of them for testing it will cost me the price of the scope.
Are there anybody thet could help me to find a solution to make it, or any idea how i can
polarize the fet to have the same function of the dual one, or give me some explication how is working?