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PostPosted: Tue May 03, 2022 2:56 pm 
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Joined: Thu Dec 16, 2021 8:20 pm
Posts: 64
So I have been using the CJ for some time with other modules.
Just finished up the mimosa and was having an issue biasing.
My Q2-S will only bias from 0 to 1.05
I cannot bias into compression.
any thoughts would be greatly appreciated.
thank you!

voltages for the board
+18 - +17.13
4.5 - 4.3
+9 - +8.6
-9 - -8.56
1 - 0.00
0 - -0.25 (is it weird that this is a negative 1/4v?)

these Q readings are bias trim min ~ max.

Q1
D - 8.6
S - 0~1.31
G - 0~1.066

Q2
D - 0~.568
S - 0~1.05
G - 0~0.184

IC
1 - .002
2 - 4.7
3 - 4.6
4 - 0
5 - .002
6 - 4.7
7 - 8.6
8 - 0
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PostPosted: Wed May 04, 2022 11:24 am 
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Joined: Sun Jan 22, 2006 1:39 pm
Posts: 5991
Location: Richland, WA
Barring a problem with the JFETs themselves, my first assumption would be that either the R10 2k4 resistor is measuring too high, or the bias trimpot is measuring too low. Are you sure it's a 10k trimpot?

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Please do not PM me. email is prefered. keith@buildyourownclone.com


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PostPosted: Wed May 04, 2022 1:23 pm 
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Joined: Thu Dec 16, 2021 8:20 pm
Posts: 64
I will check this afternoon. I will have to take out the trim pot to measure it, correct. It was the one that came in the kit. I did not measure it before putting it in. I will do the same with the resistor. And check back in. Thank you!


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