Show to make electric soldering irons transformer lead pencil wire wire solder and ice pick needed by EDWIN RUST after borrowing tiny my neighbors soldering iron and blowtorch several times I 1 decided I 1 would not rely so BO much on his generosity but provide roy my own means of soldering connections I 1 procured a transformer whose output was from 14 44 to 25 volts then I 1 took a common lead pencil some son e no 18 wire some wire solder and the handle from an ice pick and constructed ted the soldering iron as follows the lend lead was removed from the pencil and put pill in the handle then a piece of copper wire was wound around the lend lead in a close coll coil two eliches from the end the other end of the wire was attached to one binding post of the transformer likewise a piece FORIER wire bolder j for an electric soldering iron of copper wire was wrapped around a length of solder wire and the other end of the copper wire was as attached to th the e other side of the transformer apply flux to the parts to be soldered attach the lead from the transformer to the electric light socket and turn on either 14 10 20 or 25 volts and you are ready to solder touch the pencil lead to thi the solder aad nd allow it to heat until the solder aws do not touch the solder bolder to the tha wire connected to the lead A clutch pencil may be used it if the wire Is connected to the pencil and part of the pencil wrapped with tape for uso use as aa a handle but the he lead in such a pencil usually Is small and breaks eastly easily imedio digest number of turns per inch in winding coil it if you have to wind a coll coil having sixty turns of no 22 wire double covered but dont know how long a piece of tubing you will have to use take a nail or a round pencil and wind on tightly an inch of wire Ble measure asure it with a ruler and then count the turns if you find 43 turns in that inch and you need CO 60 turns altogether divide 43 into 60 and you will know to the sixteenth of 0 an inch just how much ruthm i frel how to measure turns turna space to allow for the coll coil there will be 14 inches or about 1 inches allow an eighth extra etra at least for safe tys sake eake this scheme will help you out also when aben you happen to have a piece of tubing in the shop and wonder how many turn sot wire you can get on it sometimes you have to fit specified space as often occurs when you are aie making a n portable outfit and have a 0 nice cabinet read ready to use if you can cram the set into it using the same figuring as before you can find out what size of wire will do and of course you ought to use as large a size as possible for considerations eions of sharp tuning new york mall mail r wrong connection of phones causes damage one of the easiest ways to ruin a pair of phones Is to leave them connected in the wrong direction on a one or two stage audio amplifier there Is a right anda and a wrong way to connect phones and it if they are connected incorrectly they become demagnetize and lose their sensitivity the best way to tell which Is the correct connection Is 18 to plug the phones in the second stage of ampil amplification fi and tune in a loud signal the phone caps should then be removed and one edge of the diaphragm should be lifted up about an eighth of nn an inch with the finger when the phones are connected in one direction it a V very ery much greater pull will be noticed than when connected in the other direction after this has been determined ter mined some kind of a mark may be placed on the phone terminal that was connected to the plate of the tube when the greater pull was noticed on the diaphragm end and the phones should always i be connected with the marked ter terminal minal to the plate wise to mount tubes in vertical position if a vacuum tube Is allowed to turn burn in a horizontal position it will cause the filament to sag and this will change the operating characteristics of the tube and nd will also shorten the life of the filament it Is therefore wise to mount the like tube in a vertical position cushion supports made fron sponge rubber should also be placed under the tube socket whenever possible as this helps to absorb mechanical vibrations which cause noises in the receive |