HUNTING RADIO HOWLERS

GOVERNMENT VANS ON THE TRACK

The wireless oscillators do not have it all their own way.  Re-radiated howls which spoil reception for other listeners are to be tracked down by Government experts employing the latest methods.

By the end of this month, the first of the new direction-finding motor-vans will, it is expected, be delivered to the Post Office engineers who are specially concerned with stamping out oscillation.  These vans will do their best to work in couples.

The general idea is to listen to any notable howls on frame aerials.  A compass bearing is taken of the quarry and the aerial is swung round until the sound reaches a minimum.  This gives a still closer reading.

Next, the van moves on to another spot and the procedure is repeated.  The bearing, naturally, is changed (just as a lamp-post changes it’s apparent position as you walk past it).

FINDING THE ‘LAIR’

When the bearings are plotted out on an ordnance map of the district, you will get two or more lines cutting each other and the spot where they intersect marks the ‘lair’ of the oscillator, or thereabouts, for an aerial is a length of wire which does not give a very exact ‘fix’ for this form of land navigation.

Two vans, in wireless telephonic touch with each other on a wavelength that does not interfere with broadcasting, can conduct a hunt in quite a short time and the offending listener is eventually run to earth.  (The same idea was used for submarine hunting during the war.)