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Old 24th February 2009, 10:10 PM   #11
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by Magura



Calophone?


I have seen no mail from you regarding PCB since last weekend??


Magura

calophone - resin used for violin fiddlestick ;

shoot me at >prodanovics@nadlanu.com<

neobee have numerous hickups lately
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Old 24th February 2009, 10:15 PM   #12
Magura is offline Magura  Denmark
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Quote:
Originally posted by Zen Mod



calophone - resin used for violin fiddlestick ;


To tell you the truth, I have no idea.

The flux I use is sure meant for the purpose, but is older than time, so not made under that name anymore.

Mail sent.

Magura
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Old 25th February 2009, 12:21 AM   #13
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A good temperature controlled oven, ramp up to 250C, hold temperature for 30 seconds, let the parts cool off in free air.
Can the Jfets take that heat without damage?

JJ
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Old 25th February 2009, 12:51 AM   #14
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Apparently so. You won't see me doing it, though.

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Old 25th February 2009, 05:17 AM   #15
EUVL is offline EUVL  Europe
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> You won't see me doing it, though.

Well said.
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Old 25th February 2009, 07:34 AM   #16
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by Nelson Pass
Apparently so. You won't see me doing it, though.


Quote:
Originally posted by EUVL
> You won't see me doing it, though.

Well said.

naah .........

that's working temp in all MetalDanske amps .......

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Old 25th February 2009, 10:28 AM   #17
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I was bored this morning so my nose got the better of me..

I think what choky meant was colophony, see wiki here:

http://en.wikipedia.org/wiki/Rosin
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Old 25th February 2009, 11:15 AM   #18
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by vitalstates
I was bored this morning so my nose got the better of me..

I think what choky meant was colophony, see wiki here:

http://en.wikipedia.org/wiki/Rosin

yup .

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Old 25th February 2009, 12:21 PM   #19
flg is offline flg  United States
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I haven't tried any soldering on these JFETs yet but on a daily basis I do such things with similar devices to heavy copper PCBs. Low Temp solder paste is the way to go. For something like the I-Pak I would typically use an air pre-heat stage wich is entended to heat the PCB area up, from the under side, to about 125C over 2-3 minutes. At that point I would put the air pencil to the device and surrounding area from the top side. The paste I use has a Liquidous state at about 140C(Sn42/Bi58). The pencil is ussually set to about 380C but there are alot of variables involved like distance from the device, flow rate, etc. You can watch the paste flow and get molten after about 10-20 seconds. Generally you need a tap on the top center of the device to push down and squash out excess solder and voids and you're done!
Chances are the device would not see over 175C
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Old 25th February 2009, 03:04 PM   #20
Magura is offline Magura  Denmark
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Quote:
Originally posted by flg
I haven't tried any soldering on these JFETs yet but on a daily basis I do such things with similar devices to heavy copper PCBs. Low Temp solder paste is the way to go. For something like the I-Pak I would typically use an air pre-heat stage wich is entended to heat the PCB area up, from the under side, to about 125C over 2-3 minutes. At that point I would put the air pencil to the device and surrounding area from the top side. The paste I use has a Liquidous state at about 140C(Sn42/Bi58). The pencil is ussually set to about 380C but there are alot of variables involved like distance from the device, flow rate, etc. You can watch the paste flow and get molten after about 10-20 seconds. Generally you need a tap on the top center of the device to push down and squash out excess solder and voids and you're done!
Chances are the device would not see over 175C

Exactly, this is done on daily basis, nothing new, risky or fancy. This is a well tested, everyday manufacturing principle.

The only news to this, is that it's been done successfully, with relatively low-tech machinery.

.....and naturally the fun of being able to push the limits for the Lovoltech's a bit


Magura
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