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Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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8th Dec 2007, 12:09 pm | #1 |
Dekatron
Join Date: Nov 2006
Location: London, UK.
Posts: 3,496
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Tip for successful 'heavy' soldering
I just finished making a loop antenna for my vintage SW set, which needed very heavy solder joints in two places.
I just wanted to share a tip for those that haven't yet built up their own repertoire of techiques. Basically, I had to join an area of copper nearly 5mm in diameter to a solder lug that was much smaller, and then another similar wire to a smaller diameter wire. The details don't matter, but I imagine this problem comes up over and over in different forms. The picture shows one of the joins about to be made. I have joined the two grounded sides of a 560 pf tuning capacitor to form a central connection point. The heavy wire has been cleaned and is lightly turned round the smaller wire. But it's far too thick to wrap properly. These two joins need to be excellent from an RF point of view but also physically robust, so what to do? Well, first, you can see that the thick wire is strain relieved by being weighted down by the block at the top by a lump of heavy busbar. Next, I took a section of desoldering braid. I don't actually use this for desoldering at all! I passed a small section of the braid with the flat area in contact with both areas to be joined, passed the braid round again, tautened the second turn of the braid and tied a tiny reef knot. This holds the joint very firmly in place for soldering as well as making a more permanently robust physical connection that reduces the strain on the joint. The braid is flat, and the knot is so small that it is far from unsightly. In this case, it made a big difference to me that I was able to use this very thick cable instead of something smaller: the whole effiency of the aerial depended on it. But I'll save that for another post.
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Al |
8th Dec 2007, 4:58 pm | #2 |
Retired Dormant Member
Join Date: Mar 2007
Location: Skelleftea, Sweden
Posts: 250
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Re: Tip for successful 'heavy' soldering
nice work, i think that in this case a constrictor hitch would be even less obvious and easy to tie securely. the constrictor hitch is selflocking, the more you pull the harder it will hold until something breaks.
http://www.realknots.com/knots/constric.htm as i think you found out the reefknot has a tendency to slip/loosen while tying and will "stick out" the constrictor is flattish. |
8th Dec 2007, 5:04 pm | #3 |
Retired Dormant Member
Join Date: Mar 2007
Location: Skelleftea, Sweden
Posts: 250
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Re: Tip for successful 'heavy' soldering
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11th Dec 2007, 1:48 pm | #4 |
Heptode
Join Date: Mar 2003
Location: Cheltenham Spa, Gloucestershire, UK.
Posts: 525
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Re: Tip for successful 'heavy' soldering
yes, you must have a good solder joint with an aerial, or internal "dry" spots will set up crackles! ianj
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