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Re: Slightly OT: How can I dissolve Potting Compound?
Dear Dennis: We worked on arc and gas lamp ballasts since 1970s. Then designed and manufactured 12 kV HV modules, in 1980s..1990s. The encapsulant is a very high solids epoxy, specially cured. We used
By Jean-Paul · #175847 ·
Re: I built a TM500 mainframe tester, and updated the design. Someone might find this useful?
HI Please,Larry,add me to the list.I am located at Spain. Regards.
By iMac · #175846 ·
Re: I built a TM500 mainframe tester, and updated the design. Someone might find this useful?
I would also be interested in a set of the boards, please add my name to the list. I am in Dublin, Ireland so I am aware that shipping will be somewhat more than the nominal amount suggested. I am
By Peter Mulvey · #175845 ·
Re: SC-502 transistor
Thank you to everybody! I have enough information to attempt a transplant. I'll post here the outcome Giovanni
By Giovanni IZ5PQT · #175844 ·
Re: Slightly OT: How can I dissolve Potting Compound?
Hi Dennis, I believe it's not worth the effort, I'd personally build a new one using instructions from Sam's Laser FAQ: https://www.repairfaq.org/sam/laserhps.htm#hpstoc You'll find wealth of
By Nenad Filipovic · #175843 ·
Re: Slightly OT: How can I dissolve Potting Compound?
Supposedly a 50/50 mix of formic and acetic acids will do the trick but I've never tried it. DaveB, NZ
By Dave Brown · #175842 ·
Re: Slightly OT: How can I dissolve Potting Compound?
My approach to this sort of problem (I¡¯ve done it twice in the past thirty or so years) has been to use an Xacto knife to cut the potting compound away. I never did find a solvent that seemed to
By Dave Daniel · #175841 ·
Re: A question from the unwashed relative to: I built a TM500 mainframe tester...
Just a thought: I wonder if there are TM500 modules which are particularly picky on correct functioning of the mainframe. Such a module would - use all or most of the interface - show malfunction
By Martin · #175840 ·
Re: Slightly OT: How can I dissolve Potting Compound?
I guess the point I was getting at but missed, was that it was labeled as containing acetone, but nothing else.? I try to stay away from beauty products (they wouldn't help me- hahaha!), but when it
By Dave Seiter · #175839 ·
Re: Slightly OT: How can I dissolve Potting Compound?
Also xylene. Be careful of MEK, it will dissolve rubber gloves. -- Richard Knoppow dickburk@... WB6KBL
By Richard Knoppow · #175838 ·
Re: Slightly OT: How can I dissolve Potting Compound?
Dennis, A chemist friend once told me to try Dichloromethane. I have successfully unpotted two assemblies using this. First, it is nasty stuff, I put the part and the Dichloromethane in a glass jar
By Tom Bowers · #175837 ·
Re: Slightly OT: How can I dissolve Potting Compound?
Yup. Some nail polish removers use acetone. Some removers use ethyl acetate or MEK or both. Remember MEK is used in the "glue" that plumbers use to solvent weld together plastic pipe.... in other
By Roy Thistle · #175836 ·
Re: Slightly OT: How can I dissolve Potting Compound?
Hi Dennis: I couldn't remember... but finally did. There is the defacto go to FAQ... for "gas laser tube nuts" called "Sam's Laser FAQ" ... there is good bit of information about He-Ne laser power
By Roy Thistle · #175835 ·
Re: Slightly OT: How can I dissolve Potting Compound?
I've found that nail polish remover can have weird stuff in it (besides the obvious dyes and fragrances) that pure acetone doesn't.? Last summer I poured half a bottle into the plastic tub of a
By Dave Seiter · #175834 ·
Re: Tek 465 Negative 8 volt rail issues
To wrap up my PS cap replacement: I replaced all 5 power supply filter caps. See thread above for details on replacements. I spent a couple of afternoons carefully pulling old supply caps. With all
By Dave Peterson · #175833 ·
Re: How to clean Helitrim potentiometers?
My FG503 has one Bourns pot (Frequency adjust) that is riveted closed, and two AB brand 'ModPot' pots that are held together with small flathead screws. I've had good success in opening those up and
By Jared Cabot · #175832 ·
Re: Tek 577 D1 Repair (B07xxxx)
6. B072023 2020-Nov-15~30: Broken Trace The last trace's broken into two traces:1st half of last trace and 2nd half of base trace. </g/TekScopes/photo/255563/24?p=Created,,,100,1,0,0>
By Jack2015 · #175831 ·
Re: I built a TM500 mainframe tester, and updated the design. Someone might find this useful?
Just a quick note, I have updated the files yet again for those who have downloaded them in the past. I added cutouts to the card edge connector to ensure full compatibility with mainframes that may
By Jared Cabot · #175830 ·
Re: Slightly OT: How can I dissolve Potting Compound?
Gasoline is worse, but... MEK is listed as a precursor... but a lot of industrial chemicals are precursors... and despite being listed... it produced, and used in vast quantities, in the U.S. Model
By Roy Thistle · #175828 ·
Re: Slightly OT: How can I dissolve Potting Compound?
My first experience with MEK was in early 1966 in the Navy,I spilled some on my belly, It burned like fire, buy the time I got my pants down to wash it off it was gone, just a patch of very white skin
By Leon Robinson · #175827 ·