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across the bench [season-2] the electron strikes back

cj pv10a - 28.jpg
around 37w at 120v

with 59v across the 2.2k there will be 22v across the back half of the crcrc which will be 375v feeding the transistor filter/regulator. not to mention lower magnitude of ripple to be filtered. the 18.2k could be bumped up to 22k or maybe as high as 33k for more aggressive b+ filtering but that will also increase heat generated. a different component was selected to replace the mje340 and its poorly designed factory heat sink.
 
cj pv10a - 29.jpg
a few hot spots, need to take a closer look.

cj pv10a - 30.jpg
inspecting the lift kit. also note the larger filter cap for the 12v regulator circuit (6800uf vs 4700uf factory). the cap is also shifted away from the diode rectifier hot spot.
 
cj pv10a - t7.jpeg
the precision resistors near the line stage bottles should be on the high wattage upgrade list. also interesting to see how hot the reed relays get just idling, room for thermal improvement perhaps.

cj pv10a - t8.jpeg
might be able to drop that temp down to 122f/50c depending on latch voltage spec, need to find a data sheet.
 
cj pv10a - t9.jpeg
560k with the different color mid section near the 10 zeners

cj pv10a - t10.jpeg
the revised heat sink using a different transistor, not another mje340. with a pv5 the heat sink hits 200f and beyond (unmodified). no idea how bad the pv10 might get since this is the first of that model number to go across the bench.

using my hand to isolate the thermal measurement since the sink temp is so low, oh the horror of being cool.
 
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