Noise suppression filters

[Jimc]

So what is the deal with these noise filters attached to the facet pumps? Are they needed? Has anyone removed them to see if there was any difference and if so what happened?

 

[doghead]

You do not need them.

 

[Jimc]

Awesome. Just one more thing to fail. Once I get into redoing the wiring those are coming off. They don't look too hot.

thanks dog headdog head

 

[Triple Jim]

If you're a ham and operate in the HF bands, the filters might come in handy.

 

[Jimc]

hey guys, another question concerning this. by the dc voltage regulator up by the blower wheel there is another thing that looks like a noise filter. not the red one attached to the regulator, the other one. its about 3/8" dia and 3" long or so. the parts manual says capacitor. what is this for? is it a noise filter and is it needed?

 

[storeman]

Someone smart can tell you what it does but, yes, it is needed and very expensive.

 

[Triple Jim]

Point me to a page in the parts list, or to the part in the schematic, or both, and I'll try to help.

 

[Jimc]

Parts manual page 118 item 17/20

 

[Jimc]

See that tube to the right of the terminal strip

 

[storeman]

Jim,
It has to do with regulation of AC from the stator to the DC VR I believe. I don[t understand its exact function but know it is necessary.
Jerry

 

[Jimc]

Hmm, ok jerry thanks. Mine is kinda destroyed. Wires are just solid leads and they broke off right at the tube. Do you have one if i need it?

 

[Triple Jim]

OK, thanks, I looked it up earlier. It's C1 in the schematic, a 50 uF 75 Volt non-polarized tantalum capacitor from the output of the regulator to ground, and it is indeed a very expensive capacitor. Tantalums have especially long lives, and are good at absorbing a wide band of noise, but in this application, all I can figure is that since the military was specifying, that's what was specified. If I needed one, I'd get something like a 50 uF 50V or higher rated electrolytic capicitor and observe its polarity, connecting + to the output of the regulator, and - to ground. If it charged the battery OK and there were no odd symptoms, I'd sleep fine. An example of a capacitor I'd try is:

http://www.mouser.com/ProductDetail...=sGAEpiMZZMtZ1n0r9vR22QsCVzpjG1J18Kh8sLvZs0U=

Insert the usual disclaimers here...

 

[Jimc]

thanks jim, i did a little digging as well. not really sure of the function of this thing other than as you said to absorb noise but it is expensive. i did find them brand new for $58. sears parts direct wanted around $180..lol. i like your cap better though. $3 is more like it. here is a link to the one i found. i found the real detailed specs of this one and the one i have and they are exactly the same.

http://www.tedss.com/CL23BL500TNE/?gclid=CJWa0tCrmbUCFVCd4AodRA0AdA

 

[Triple Jim]

I think the main purpose is to smooth out the output of the regulator, especially if the battery isn't up to the job. Anyway, I've never paid $58 for capacitor in my life, and if I need to replace C1 in my 003A I sure won't do it without a big fight.

 

[Jimc]

i hear ya on that. since the original one is 75v i looked at the one you have posted the link to and they do make it in 100v version instead of 50. i assume that would probably be more within spec and give a little extra headroom?? if im not mistaken a cap is only going to put out what goes into it voltage wise.

 

[Jimc]

you know i just cut the crap off the end of the one i have here and with the insulation off there might be just enough lead that i can solder a new wire onto it. ill give it a shot tomorrow.

 

[Triple Jim]

i hear ya on that. since the original one is 75v i looked at the one you have posted the link to and they do make it in 100v version instead of 50. i assume that would probably be more within spec and give a little extra headroom?? if im not mistaken a cap is only going to put out what goes into it voltage wise.

You can do that. I chose 50 because it's nearly double the normal voltage at the regulator output and will work fine for many years. A capacitor is a charge storage device, sort of like a mini-battery, but without a fixed terminal voltage, so you're right that whatever voltage if applied to it is what it will see. Its voltage rating is the maximum you should apply to it.

If you can solder to what's left of the old one, great. I remember someone else recently doing that successfully.

 

[1800 Diesel]

Hmm, ok jerry thanks. Mine is kinda destroyed. Wires are just solid leads and they broke off right at the tube. Do you have one if i need it?

Had the same problem with an MEP2 a few months ago. Wire broken off near the end of the capacitor. Scraped away some material IWO the "nub" and soldered a new wire to the nub to allow connection to the TB. Unit's been working ever since....

 

[Jimc]

After i cut away the plastic film from the end i definately have more there than i thought. There is actually plenty there to solder to. The wire goe into the end. Its not flush with it so i have a good 3/16". Thanks for your insight guys!