Particularly the coils manufactured by Neosid looks a little bit filigram.
Thereby some homebrewer are keep away from the project to build its own radio station.
That does not have to be, because there is a simple trick, in order to get also without large machines very thin copper wire with an diameter of only 0.1 mm precise on the coil body.
Preparation of the wire
With me all wire ends were tinned before. Also with the 0.1 mm wire I trusted not in the thermal inertia. Maybe I saved so perhaps unnecessary annoyance with bad soldered connections due to still existing film of varnish/isolation. To tin I use already the several times described blob method. At the same time the wire end which should be tinned is to put from the end into a thicker tin bead on the tip of the hot soldering iron. The wire will be tinned cleanly during alternately pushing in and pulling out. If have set off somewhat film of burned varnish on the wire, then it disappeared at the latest after first pulling the wire through two fingers.
The make of the beginning and the end of each coil is also very simply. For it simply wind the tinned wire end around the angular coil feet tautly and the specified way.
How do I get the turns side by side?
After winding the begin I weight the free wire end with a laundry-clammy. In addition, every other reasonably heavy object is usable − only the wire may not tear. At the onset of the experiments I holding tight the coil horizontally with the thumbs and index fingers of both hands and let the weighted wire end hang freely down. In the meantime I discovered that holding the coil with a toothpick is simpler. The pick fits into the coil body, whereby this is moveable comfortably with two fingers. Thereby it's now simply possible to turn the coil body and to wind up the turns in this situation as closely as possible side by side.
I also tried to hold the coil body only with a hand and to wind the wire with the other one around the body. The windings did not become so firm however and the turns were more difficult to apply.
From the gentle force on the strength of the laundry-clammy results a firm coil. And you can see direct on the windings and recognize errors in such a way fast. Nevertheless once if a gap should have developed between the turns, then it can be eliminated with a fingernail by pushing the windings together. The end is then wound and soldered again, as describes briefly already above, tautly over the coil feet.
QRPeter, DL2FI, makes a small loop into the freely down-hanging wire end and hangs up the side cutter anyway necessary when homebrewing. That exercises somewhat more force on the wire than the nevertheless quite easy laundry-clammy.
How do I realize a tap?
Twisting and tinning the thin wire was too toilsome to me. In addition then two wires would have to be wound around the coil feet. Therefore I refrain from twisting and tinned only 5 mm of the wire in the correct place (for a test lead the wire to the feet before). The tinned piece is wound like used two or three times around the feet and led without separation/splitting of the wire by the groove in the coil again to the coil body. Afterwards the second coil can be applied.
The length of the taped feet do not pin differs thereby from that of the external feets and the coil can be soldered without an additionally distance on the board. And have no fear, that the three wire turns around the feet could slips. The feets are specially roughened, so you can solder the wire at the end of the procedure and not in between. For tinning the wires clamp the coil body with the feets upward careful in a vice or other clamping device. Therefore solder the wires with the hot soldering iron and something tin solder. But please do not heat the connection for a long time. Otherwise the feets become so hot that they slip in the plastic base of the coil or fall out.
Theoretically one would have to be able oneself to save tinning the wire ends before the winding on the feets. The applied varnish is actually so thin that it burns nearly immediately and insignificantly might not extend the soldering time thereby. But I am there more careful and tin the ends before.