I had a Knights 10 MHz OCXO that I really liked for my ham stuff,
partially because it was clean and stable, partially because it worked
on 12 V making it great for mobile radio use.
Quite a few years back I messed up and hooked up the battery supply
backwards which killed it. I liked it enough that I opened it up,
replaced a bunch of semiconductors and fixed it. The circuits had
surface mount parts, so I guess it was late 80's or early 90's vintage.
It was a standard large metal can format, about 2 x 2 x 4 inches,
soldered together on the connector end.
Trying to break the solder seal would have been a lot of work. I'm sure
the solder flowed at least 1/8 inch down into the groove between the end
piece and the can. I have a milling machine and I used it to cut a slot
around the outside of the can. The deepest edge location of this cut was
about 0.225 inch down from the end edge of the can. I can't remember
exactly how I decided where to make this cut, I probably made a test cut
in one spot. What I did was cut beyond the solder joint and just deep
enough to go through the outside can, but there was still overlap
between the inner end piece and the can so it was not too difficult to
reassemble after fixing the electronics. I think I tack soldered the
pieces back together and then sealed it with silicon. Finally I wrapped
the outside with foil tape to electrically seal the slot.
If I didn't have the milling machine and slotting saw, I think I would
try my method with a dremel tool by hand before I would try to unsolder,
either mechanically or with heat.
For perspective, I had earlier tried to unsolder a smaller tcxo can. I
used a propane torch with a gentile flame. By the time I got the solder
melted and managed to separate the two halves, I had also desoldered a
number of random devices from the internal circuit board. Unsoldering a
can without overheating the contents is not easy.
So, one more approach for your project.
Joseph Gray wrote:
That's a good idea. I just spent the better part of the past hour
trying it. So far, I have made a nice pile of solder shavings and have
cramped my hand. I haven't succeeded in opening the OCXO, however. The
base fits very snug into the can, so there isn't much more I can dig
out. I'll make another attempt tomorrow, after my hand recovers.
Joe
On Fri, Dec 4, 2009 at 8:46 PM, Ed Palmer <[email protected]> wrote:
I recently had good luck opening up a soldered oscillator with a utility
knife. Rather than use the sharp edge, I used the back edge of the blade.
That way, instead of trying to push the solder aside, the blade actually
digs it out of the crack - sort of the way a cutter works in a metal lathe.
Of course, great care is required to ensure that you don't amputate
something!
Ed
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 4661 (20091204) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
