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heathkit sb 614

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kinkydoints:
I have gotten my HV circuit kit to replace caps and resistors on the high voltage circuit , on examination looks like these parts may have been changed at some point. There are two 70 mf caps next to the 3   0.1mfd +-10% 1600vdc cdent caps...these two aluminum caps do look original see pic for the location . The parts book call for these to be 70 mfd  electrolytic... but no idea of the voltage of these two big caps. Id like to change them also.  they are at c128 c124 on the board. on page 25

kinkydoints:
Im not a electronic wiz but if I can read the schematic the voltage is 290 vdc indicated by a oval with the 290 in it going to c128 70 mfd cap , c128 is grounded to circuit board ground, 209 vdc continues to r156 and r155 by zd 101 zd 102 to the c124 cap 70 mfd  to +180v "source" looking at the fold out schematic on page 103. I will need a 290 v or better cap in these two spots?  Im trying here guys.  but are caps listed a ac volts?

k7rmj:
I took a peek at your schematic in the manual. They both C124 and C128 are on the line that provides 190 VDC. The voltage coming off the bridge rectifier appears to be 290 VAC. I would suggest 350 to 450 VDC for those two caps just to be on the safe side. It may be easier to find 450 V caps but anything from 350 V to 450 V should be safe, IMHO. Anything over 450 V would be okay too.
Good luck with it and let us know how you make out.
73  DE K7RMJ  Frank

kinkydoints:
Thanks for the feedback k7rmj Im getting all my parts together and will getthis nice old monitor back to work again.

k7rmj:
Glad I could help a little. Good luck with it and keep us posted on progress.
73 DE K7RMJ  Frank

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