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Replacement filter caps for SX-3900

Raccoon1400

Raccoon1400

Super Member
I need replacement filter caps for my 3900. They are 15000uF, 71WV.
The lead spacing is 2.5cm, and the distance between the centers of the two caps is just under 2". There are 5 leads. I can't find anything that will fit. There was a panasonic cap on digikey that had the same lead spacing and number of leads, but I just realized it's too fat.
Any suggestions? I really want to get this thing running.
 
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The physical factors predominate on this replacement, as they help mount the PC board at the correct height over the regulated voltage transformer. Modern replacements are usually smaller, and these are unusually tall and thin. (imo)

So far I have not found any that actually bear replacing.

There will be small amounts of AC present at the terminals under operation. There are with any receiver. If you are getting strange readings of ac over dc your meter may be the reason, and you will need to add a 0.1uf DC blocking cap in series with the meter leads. Be sure the cap is over 100 and preferably 200 volts.

After that, a difference in AC voltages of about a magnitude (0.5v vs 5v) is where I would start being concerned.

This is a can of worms you don't want to open unless you have to.
 
Raccoon1400 said:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P10647-ND

I think I can make this one fit.
Click to expand...


slightly smaller diameter, no problem, but almost an inch shorter. You will need to find and use stand offs to mount the cap clamps higher by an inch.

Terminal circle is 0.886 versus about an inch, a few new holes needed, but you should still be on the foils....

Congrats, you may be pioneering the standard replacement... :D

(p.s. I have the assembly NEXT to me right now, with a dial caliper, to check it all)
 
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I guess I'll try that one. It looks like closest fit. There are ones with the same lead spacing, and number of leads, but they are too fat.
When I tested the cap, the AC voltage under operation was 150mVAC, and there is a hum in the background. The previous owner had already figured out the issue and removed the cap, but didn't follow through and left it half apart , so I was left with a puzzle.
 
Those Panasonic CE THA 15,000 caps are the exact ones I put in my 3900. They work like a champ. A bit smaller in diameter and a little shorter. I used standoffs made of plastic to space the clamps down to fit,, then placed a wrap around the caps to ensure the clamps ere able to be tightened properly. As good as or even better than new as far as fit goes. I can provide pictures if you need them.

EDIT: Photos uploaded...
 

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measure ALL the regulated supply voltages and check the ac ripple voltage on their DC supplies, which is COMPLETELY separate from those caps you just replaced.

do you need a list or can you find them and post them yourself? +/- 54v, +/-32v regulated (and a few more) as well as +/- 65v or so unregulated.
 
markthefixer said:
measure ALL the regulated supply voltages and check the ac ripple voltage on their DC supplies, which is COMPLETELY separate from those caps you just replaced.

do you need a list or can you find them and post them yourself? +/- 54v, +/-32v regulated (and a few more) as well as +/- 65v or so unregulated.
Click to expand...

A list would help. I have a hard time making sense of these units. They are a tangle of wires and boards.
Thanks
 
sx-3900, awr-210 board (behind the front panel, on the power switch side)

pin 22 +54v dc regulated
pin 23 +32v dc regulated
pin 21 ground
pin 26 -13v dc regulated
pin 25 -21v dc regulated
pin 24 -32v dc regulated
pin 20 -54v dc regulated
pin 18 +12.8v dc regulated
pin 11 +5.5v dc regulated
pin 13 +20v dc UNregulated thus it can vary
pin 29 +48v or so driving the soft start relay.
pin 4 + or - 20v protect signal voltage, can be positive or negative depending upon model
pins 5 & 6 have about -14v dc and 3v AC on them for floroscan tuner display.
pins 1 & 2 have only 3v AC on them for floroscan VU meter display.



all the usual warnings apply, get a good bare metal chassis ground for your black mater lead, and insulate all but the tiniest tip of the probe of your red lead to avoid shorts when it slips.

to measure AC ripple on a DC supply, put a 0.1uf capacitor (100v or more) in series with the red multimeter lead.

But if there is significant AC ripple, the DC voltage should be incorrect anyway.
 
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I finally got a chance to check the voltages. Pin 18 and 11 don't have any voltage, DC or AC. All the others are very close to your values. Relay clicks in less that a second.


EDIT: noticed a couple caps on the board with their wrapper shrunken past the top of the cap. Looks like this thing saw a lot of use. I guess it would be best to rebuild the board.
 
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well, yes... but with the difficulty at getting to it, and some clearance issues on replacement parts, it IS a bit of a job...

thus inspecting/testing the board and rebuilding the board consume almost the same amount of effort.

pin 11 depends upon pin 18 to operate.

pin 18 uses a reference voltage from pins 22 & 23 power supply.

pin 18 circuitry is not near the hottest point of the board.
 
markthefixer said:
well, yes... but with the difficulty at getting to it, and some clearance issues on replacement parts, it IS a bit of a job...

thus inspecting/testing the board and rebuilding the board consume almost the same amount of effort.

pin 11 depends upon pin 18 to operate.

pin 18 uses a reference voltage from pins 22 & 23 power supply.

pin 18 circuitry is not near the hottest point of the board.
Click to expand...


I have the caps picked out, keeping the clearance in mind. My list mostly uses panasonic FW.

What is the difference between 2SD313 and 2SD313P? From what I can tell MJE3055TGOS-ND is a suitable replacement.
 
use mje15032 mje15033's.

you are NOT using my list and will repeat their engineering mistakes.
 
sx-3900 (and D7000) PSU parts substitutions by MTF

q1,q2 2sk34 - leave alone, unobtanium

q3,q9,q11 2sd313 to 863-MJE15032G
863-MJE15032G npn to-220 bce 250v 8a 50w 30mhz 70hfe $1.30

q4 2sc1885 to 512-KSC2383
q10 2sc2575 to 512-KSC2383
512-KSC2383YBU to-92L ecb 160v 1a .9w 50mhz 160-320hfe $0.17

q5 2sa912 to 512-KSA1013
512-KSA1013YBU to-92L ecb 160v 1a .9w 50mhz 160-320hfe $0.34

q6 2sb682 to 863-MJE15033G
863-MJE15033G pnp to-220 bce 250v 8a 50w 30mhz 70hfe $1.30

q7 2sc1915 to 512-KSC2690
512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.40

q8 2sa905 to 512-KSA1220
512-KSA1220AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.39

"datasheets:"
more robust replacement:
512-KSA1013YBU to-92L ecb 160v 1a .9w 50mhz 160-320hfe $0.34
512-KSC2383YBU to-92L ecb 160v 1a .9w 50mhz 160-320hfe $0.17

increased size for power dissipation, originals undersized.
512-KSA1220AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.39
512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.40

takes heat better:
863-MJE15033G pnp to-220 bce 250v 8a 50w 30mhz 70hfe $1.30
863-MJE15032G npn to-220 bce 250v 8a 50w 30mhz 70hfe $1.30


capacitors:

c1 2.2uf 50v 2.2 50 647-UPW1H2R2MDD
c5 10uf 50v 10uf 63v 647-UPW2A100MED
c24 10uf 50v 10uf 63v 647-UPW2A100MED
c8 10uf 63v 10uf 63v 647-UPW2A100MED
c9 47uf 25v 47 25 647-UPW1E470MDD
c12 47uf 50v 47 63 647-UPW1J470MPD
c13 47uf 50v 47 63 647-UPW1J470MPD
c10 47uf 63v 47 63 647-UPW1J470MPD
c11 47uf 63v 47 63 647-UPW1J470MPD
c16 100uf 25v 100 50 647-UPW1H101MPD
c17 220uf 16v 220 35 647-UPW1V221MPD
c22 330uf 25v 330 35 647-UPW1V331MPD6
c23 470uf 6v 470 25 647-UPW1E471MPD
c20 470uf 16v 470 25 647-UPW1E471MPD
c21 470uf 16v 470 25 647-UPW1E471MPD
c15 1000uf 35v 1000 35 647-UPW1V102MHD

c3,c4 220uf 80v size constrained!! Critical!!! 12.5mm dia max
2 647-UVZ2A221MHH 100V 220uF 12.5x25 3,4


bom text block:

647-UPW1H2R2MDD
647-UPW2A100MED
647-UPW2A100MED
647-UPW2A100MED
647-UPW1E470MDD
647-UPW1J470MPD
647-UPW1J470MPD
647-UPW1J470MPD
647-UPW1J470MPD
647-UPW1H101MPD
647-UPW1V221MPD
647-UPW1V331MPD6
647-UPW1E471MPD
647-UPW1E471MPD
647-UPW1E471MPD
35 647-UPW1V102MHD
647-UVZ2A221MHH
647-UVZ2A221MHH
512-KSA1013YBU
512-KSC2383YBU
512-KSC2383YBU
512-KSA1220AYS
512-KSC2690AYS
863-MJE15033G
863-MJE15032G
863-MJE15032G
863-MJE15032G
 
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