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Old 9th Nov 2019, 11:01 pm   #29
evingar
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Join Date: Oct 2003
Location: Newbury, Berkshire, UK.
Posts: 1,770
Default Re: Soldering Iron For PCB's

Quote:
Originally Posted by Radio Wrangler View Post

Now for Metcals:

I have two. I use one in each hand under a stereo microscope for SMT work. All they cost me were the bits, though those are about £18 apiece.

Metcal bases, the power units are very expensive indeed. But they are also staggeringly unreliable. This doesn't sound good, does it?. People leave soldering irons on all day. Metcals are designed to be switched on right before soldering and straight off afterwards. Tey heat in only a few seconds. They are intended to let you swap a tip and be going again in under 10 seconds. Leave one on as a habit, and the base will die. Firms chuck out dead bases
So here is an opportunity for someone who can do a bit of electronic repair. The base unit supplies up to 70W at 13.5MHz into a nominal 75 Ohm load and throttles back the power into a mismatch. The use international rectifier hexfets as their power amp stages and that's all they usually need to get them going. Schematics are on the web.

So don't believe these things are too expensive. Collect some dead junk and hit it with some thought and engineering. You can have a dream setup for little cost. It will take time, but keep word out and keep your eyes open. You wouldn't want to miss an opportunity.

David



Another vote for Metcal.
I can't say I've personally found the MX500 type unreliable, even when abused. I have to confess to disabling the auto switch off on my home ones

I have a pair - both bases bought on ebay for around £100 - they were rigged for 110V but easy to change. I've also used them at a variety of places I've worked over the years.

With respect to the tips, they are expensive and care in needed. If you change them with pliers they will have a short life - always use the rubber thing attached to the lead. Ditto using a sponge that is flooded with water - it shortens the life of the tip no end. Use a slightly moist sponge only.

Thermaltronics do compatible tips that are cheaper than Metcal's own offerings. I've found them to be just as good.

http://www.thermaltronics.com/pseries_ref.php
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