7412533580

New Jobs for Tubę Pins

By ROBERT RUSSELL

Fig. 1. Raw materials: antenna wire and lube pins.

HAVE YOU evcr considered whał a shamc it is. whcn a vacuum tubę expires. 10 discard complctcly so in-tricately contriyed a component that still incorporatcs a variety of inherent-ly uscful materials? In the ease of oe-tal-typc tubes. at least. thorc is sonie simple salvaging you can do. There are literally dozens of places where the tubę pins can be used to make dcpend-able. compact connectors. often pro-viding a morę versatile set of terminals than do other connectors. Best of a 11. once the tubes thcmschcs are useless. the chief raw materials are aeailable free. Principal additional materials needed are the ”grippers’' or pin insert s found on octal sockets.

For his sereice hencli. the author bas used tuhe pins to simplify sueli connec-tors and connections as singlc-wire leads in several longths. coaxial cables. spccial lead-to-lead e.\tendcr connections. leads that accommodate a choiec of plug-in terminals including alliga-tor elips, linę cords madę to simulate TV cheater cords. and standard plugs with tube-pin input. Seeeral Instruments and other equipment have been adapted with tuhe sockets to which input. output, and power connections have been brought out for simple hook-ups. Many other applications will occur to users who adapt this tcchnique to suit their individual needs.

In addition to the pins and grippers already mentioned (and. of coursc. the items to which you intend to attach the pins i. one other materia! is needed: a suitable piast ic. This too is avai)able in the service shop or easily procured. Polyethylenc. which may be taken from ordinary TV twin-lead antenna wire. is highly suitahle hecause it is tough and durahle, yet easily molded with the right techniguc. Sec Fig. 1 for this piast ic and the pins.

To obtain a suitable length for molt-ing and molding. simply strip away the coppcr conductors from this length. To melt it. a błock of wood with a hole about •)$* inch square and about Va inch deep is needed. The piast ic. which or-dinarily sticks to evcrything including the wood and ones fingernails. is sim-ple to tanie. Oiling the hole in the wood and the fingernails will procent stick-ing. Use a smali soldering iron to melt the plastic gradually into the hole. If the iron bccomes too hot, it will bogiń to break down the plastic. producing smoke. carbon. and possihly gases that should not he inhaled. There are sov-eral ways of controlling the iron’s heat. if this hecomes neeessary. One con-venient way is to dip the iron occa-sionally into a glass of water.

Ocłober. 1959

Fig. 2. The three sleps in connecting a lead to a pin irom a discarded lube.

Wiłh smali amounłs of ingenuiły, effort, and ex-pense, you can make up a yarieły of connectors.

Fig. 3. How a lead-to-lead connector (center) is used lor extension cables.

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Fig. 4. Construction details lor some ol the technigues described in the text.

Fig. 5. Two-pin a.c. connector and matching socket lor instrument case.

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With the polyethylene prepared. we must ready the other raw materials. To free the pins from the tubes. wrap the lat ter in paper or cloth indicid-uałly and smash the glass. The pins can he chipped away from the sockets readily with a chisel. ^r|*hc soldering iron can he used to elear, away any connecting leads inside the liollow pins.

Tuhe sockets will be neeessary. to obtain the grippers or pin inserts and also to make up sockets for equipment-panel connectors. For the lat ter appli-cation. plastic tuhe sockets will generał ly be used. For sahaging grippers, wafer-type sockets are best. The lat ter are easily dismemhered l>> cutting or crushing the plastic around the two rivets of each socket. This permits separation ol the two plastic wafers making up the socket. between which the pin grippers are sandwiched and lield. Dismantling a single wafer socket gives you a fair supply of eight grip-jiers. Each of the lat ter consists of a strip of metal wrapped around at one end to clasp the tuhe pin with the other end bent over isre drawing to the left in Fig. 4A \ as a single tab with a hole at the end to accommodate connecting leads. In most applications. the gripper will be morę uscful if pliers are used to sgueeze the tah closer to the pin-hold-ing body (to the right in Fig. 4Ai. In some cases. it will be desirabie to soldcr the tab to the maili body.

To make up comcnt ional leads. obtain wire of the desired type and cut to size. Two-conductor. plastic-insulnted linę cord is <iuite suitable: it can be split down the middle to provide neat, durahle, singlc-wiro leads. For smaller size and greater fle.\ibility, #18 or #20 stranded hook-up wire can he used. Strip about \ inch from each end of the wire, twist the c.\posed conductor. and tin it gencrously. If the conductor is too thick for insertion in the tuhe pin. puli back a few strands and wrap them around the remaining ones near the start of the insulntion.

Fili the hollow of the tuhe pin with molten solder and. while the soldcr is still fluid, insert the tinned end of the wire. If the soldering iron can he rested on a hase during this operat ion to free hoth hands. a pair of long-nose pliers iCoiithiuetl on puye 159)

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