Please help me identify these .45 3kv TRW caps

kstlfido · 5th October 2011, 01:48 AM

Hi folks-

I came across a cigar box of these TRW .45uF 3kv (!!) caps recently.

They are metal cylindrical with axial leads. 2 5/8" (66mm) long; 11/16" (18mm) diameter.

Hermetically sealed ends. Gold plated leads. The type on the caps reads:

2760307-2
TRW 957
LMSC-35-1
.45 +- 10%
3000 VDC

kstlfido · 5th October 2011, 01:50 AM

Could anyone here shed some light on what these caps are, particularly the dielectric? Any help would be greatly appreciated.

Thank you- Kent

TheGimp · 5th October 2011, 02:34 AM

Cut one open and dissect it.

Just wear gloves in case it is oil filled, could be PCBs.

What do they measure? .45uF?

tomtt · 02:47 AM

Quote:

Originally Posted by TheGimp

Cut one open and dissect it.

i wouldn't-

higher voltage caps are not all that cheep.

post #5 -

TRW Capacitors Question

kstlfido · 5th October 2011, 03:04 AM

Yes, they measure around .45 uf (4.3, 4.6, 4.4, etc.).

gmphadte · 5th October 2011, 04:09 AM

Tektronix 2235 scope has similar caps. I also want to know what they r.

Gajanan Phadte

FlaCharlie · 5th October 2011, 10:06 AM

Caps with hermetically sealed glass ends are oil filled, usually paper in oil. Unless you can find some manufacturer specs somewhere you might have to open one up to check the dielectric. As mentioned earlier, the oil could contain highly toxic PCBs so take extreme care if you open them. Not sure exactly what 'extreme care' would entail. Gloves and mask at least. Then the cap should be disposed of as hazardous waste.

Probably easier to just try them and see if you like them.

. . . Charlie

gmphadte · 9th March 2012, 10:44 AM

They r PIO i.e. paper in oil

For photo, go to
diyaudioprojects.com/Solid/JFET-Phono-Preamplifier-Kit/

Gajanan Phadte

TheGimp · 9th March 2012, 03:40 PM

Those are soviet not US made caps.

This company claims they are film/oil caps, but do not specify what film.

8 NOS vintage TRW 45uF capacitors 3000VDC 3kv hermetically sealed film oil caps

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5th October 2011, 01:50 AM	#2
kstlfido diyAudio Member Join Date: Mar 2006 Location: Berkeley, CA	Could anyone here shed some light on what these caps are, particularly the dielectric? Any help would be greatly appreciated. Thank you- Kent

5th October 2011, 02:34 AM	#3
TheGimp diyAudio Member Join Date: Aug 2009 Location: Johnson City, TN	Cut one open and dissect it. Just wear gloves in case it is oil filled, could be PCBs. What do they measure? .45uF?

5th October 2011, 03:04 AM	#5
kstlfido diyAudio Member Join Date: Mar 2006 Location: Berkeley, CA	Yes, they measure around .45 uf (4.3, 4.6, 4.4, etc.).

5th October 2011, 04:09 AM	#6
gmphadte diyAudio Member Join Date: Jul 2003 Location: Dona paula, Goa	Tektronix 2235 scope has similar caps. I also want to know what they r. Gajanan Phadte

5th October 2011, 10:06 AM	#7
FlaCharlie diyAudio Member Join Date: Feb 2004 Location: Gainesville, FL	Caps with hermetically sealed glass ends are oil filled, usually paper in oil. Unless you can find some manufacturer specs somewhere you might have to open one up to check the dielectric. As mentioned earlier, the oil could contain highly toxic PCBs so take extreme care if you open them. Not sure exactly what 'extreme care' would entail. Gloves and mask at least. Then the cap should be disposed of as hazardous waste. Probably easier to just try them and see if you like them. . . . Charlie

9th March 2012, 10:44 AM	#8
gmphadte diyAudio Member Join Date: Jul 2003 Location: Dona paula, Goa	They r PIO i.e. paper in oil For photo, go to diyaudioprojects.com/Solid/JFET-Phono-Preamplifier-Kit/ Gajanan Phadte

9th March 2012, 03:40 PM	#9
TheGimp diyAudio Member Join Date: Aug 2009 Location: Johnson City, TN	Those are soviet not US made caps. This company claims they are film/oil caps, but do not specify what film. 8 NOS vintage TRW 45uF capacitors 3000VDC 3kv hermetically sealed film oil caps

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