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bill  
#1 Posted : Wednesday, December 6, 2017 1:14:22 AM(UTC)
bill

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I couldn't find original QN1 /2 parts and used MJE15032G instead. Is this part ok?

Input voltage is approx. 18 VAC
I set VR1 to about 440 and VR2 to 997.
Output voltage is 13.2 vdc

I cant change the output voltage by adjusting VR2 (10K).

I'm only using the positive side of a V1 Placid bipolar board.

Any help is appreciated.
bill  
#2 Posted : Wednesday, December 6, 2017 7:50:23 PM(UTC)
bill

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I had previously found a wrong transistor QN4 and swapped it for a new correct one. Maybe others were affected?
SCompRacer  
#3 Posted : Thursday, December 7, 2017 8:12:16 PM(UTC)
SCompRacer

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I connected transformer incorrectly and ended up with fixed voltage (21v) on positive side of HD BP 2.1.

I ended up replacing QN 3, 4, 5 and Ref1B, 2B.

Check under Twisted Pear parts page. IIRC they sell the MJF122G and LT1034IZ. Check the parts list for supplier part numbers, like Mouser, digikey.

Good luck.
bill  
#4 Posted : Friday, December 8, 2017 2:56:09 AM(UTC)
bill

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Thanks. But are MJF122G and LT1034IZ suitable for the v1 boards?
bill  
#5 Posted : Friday, December 22, 2017 3:43:23 AM(UTC)
bill

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Anyone?
Brian Donegan  
#6 Posted : Saturday, December 23, 2017 2:13:20 PM(UTC)
Brian Donegan

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The LT1034IZ is fine. The MJF122 will not work well with the older Placid boards, as it is a darlington. I have abunch of the older transistors (FJPF5200/1943) available. I will add them to the parts bin.
bill  
#7 Posted : Saturday, December 23, 2017 10:31:28 PM(UTC)
bill

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Thanks Brian. I placed the order :-)
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