A FEW TIPS

Shannon News, 11 September 1928, Page 1

A FEW TIPS

Porcelain-Insulators for Aerial.— Glazed porcelain insulators and highgrade' typua pf-moulded composition insulators are best suited for aerial insulation. Spreaders should not carry parallel insulators on each wire; this.: reduces the insulation instead of ini-

proving it. The insulators should be placed in series, aiid strung 'at each end of the spreader rope. ' i Phone Cords. —It is often found that' phono cords fray whore they enter ■ the terminal tags. This can be pre-

vented by pushing two lengths of lyclc-valve rubber, each about linch. =*> long, on to each terminal tag. Force.. the rubber on to the broad part of the 'p ':ag, and roll a small portion of the , ■libber nearest to the cord back on it- ,• self. Push the rubber still farther on,. /. and then the rolled-back portion can ’ >c unrolled on to the ce.d. . '

Hand Capacity Ejects.— A. metal ' H eld will reduce hand capacity effect to a minimum in a set. It has been . ilouhtf that in a -well-constructed, care-''', "ully-designed sot capacity effects are ■■ .bsent. _ . ‘ Use of By-pass Condenser. —It is a good plan to use such a condenser, although the set will operate without, "'y; It usually improves the control, of the \ regeneration. ‘ > Range of Crystal Receiver. —The consistent range of a crystal receiver is rrom ten to twenty-five miles. How)vcr, under freak conditions, receivers '"'j )i this type have been known lo pick. up signals of stations more than 100 J miles away. . „ ' ' ‘ Loose Yalve Contact. —When the valve does not fit properly in its .sock-.. et a toothpick or a match-whittled down > to form a wedge can be placed between ‘ij the socket and the valve to hold it , ightly in place. ■ Crystal Sensitivity.—A sensitive spot on a crystal .soon loses its sensi- > tiveness. When one spot is exhausted . j. find another, until the crystal is-fin is.hed. Keep your fingers off the cry-: stal. ' Short-Wave Aerials. —It is common,; ' knowledge amongst many persons that ’• on the short wave lengths correspond- ; ingly short aerial should be used. This * is not so, as experiments have proved. It was found that for five-metre recep- ? ' Con the longest aerial possible,'but no earth 8 connection, proved to be the best possible method of pick-up. reception on%ave lengths from fifteen .metres.up to 100 metres an aerial with an overhaul length of 250 ft is advisr able. " This will give a greater pick-up of R.F. currents. Utilising the Old Valve. —A receiv- ■ ing or transmitting valve that will nqjf oscillate any more can be made to serve as a rectifier valve as long fis the plate or grid is not shorted to the .. filament. The socket springs connect- s ing to the grid and plate of the valve ;; should be- wired together, so that the ! . J valve will carry more current. - Testing a Valve.—The best test for.;' K > a hew valve is to put it in a regenera- i tivc receiving set or oscillator, and termine whether or not it will oscillate; -. This is true, because a valve that, will , oscillate will also detect and amplify (the other turn functions of a valve). This is the tost often used by manufacturers and dealers. , A valve that wiU not oscillate is practically . worthless , , for any use but rectifying.