Tips and Jottings

Radio Record, Volume III, Issue 14, 18 October 1929, Page 31

Tips and Jottings

A Makeshift Drill. _ [= sometimes occurs that a small hole is in an ebonite panel, and no drill is available. An ordinary pradawl will make a very good substitute, and it is surprising how quickly it bores a hole. ‘Me method of using is to rotate the tool backwards and forwards through about half a turn, pressure being applied to the hanflle. It is advisable to occasionally to lift the point out of a hole and’ place it back in a different position, so as to ensure that a really circular hole is made. Indoor Antenna. AN indoor antenna is quite efficient | for short-wave work, as, when working on high frequencies, height and length do not-matter very much. Many short-wave amateurs, in fact, use such an antenna in preference to an aerial, and excellent results have been obtained by some with a vertical indoor antenna only six feet long. Atmospherics are considerably reduced in strength by the use of such a system. Indoor antenna should not be made too long, and should be run near an outside wall of the house. This will help to keep it away from the -house lighting system, thus avoiding the chance of picking up hum. . A "Mains" Precaution. NB of the easiest and most effective precautions that can be taken with a receiver, using an eliminator, is to insert a fixed condenser in both the aerial and the earth leads at the point Where these enter the set. When buying large fixed condensers for this use, remember that they should not be worked at their "test" voltage. Usually the working voltage should not be more than half the test voltage, so that for use. on 200-volt mains, condensers test--ed at 400 volts or over should be used. An Aerial Hint. A=RIALS which are quite taut during wet weather, slacken considerably when conditions are dry. This

sagging generally means that the leade in. which would previously clear the house, is now dangerously near it, and a slight wind may swing it against metal gutterings. Thus signal loss ig caused, or more often a series of irri tating noises occur which are frequent» ly attributed to atmospheric troubie. Whenever there is a long spell of dry weather, an aerial should always’ be slightly ‘tightened to avoid this unwanted sag, though if too much slack is taken in, a break would prob ably occur when the aerial becomes we once more,