RADIO PLAYS PART IN POLICE PATROL

Chronicle (Levin), 17 June 1947, Page 3

RADIO PLAYS PART IN POLICE PATROL

(Speeial Correspondent.)

Reeeived Monday, 7 p.m. LONDOX, June 16. Inquiries on behalf of New Zealand have been made at the Home Office in Whitehall reeently regarding the use and latest developinents in very high frequtency radio conimunieation by the Police 'jforces. The British officials readily 'eooperated and willingly pro- , vid^d inf ortnatiou. ' This in'cludhs detailg oi' the latest and most u'p-to-date niethod of pfoviding police; radio ..communication not only for citi.es and t'owns, where 'it is now eoihmOniy in -use, but also for country areas. By using automatic relay stations whieh increase the range of v.h.f. signals, and by employing amplitude inodulation instead ot frequency inodulation, so favoured by the. Americans, British radio cngineers find that they are able to double or treble the area in whieh the communication may be used. Two-way communication is now readily possible u { > to 30 to 40 miles and within an area of 1200 square miles or more. As a result radio communication for the police in everv county in Britain is progressing activelv. Already this new system is operating successfully in Hertfordshire where it enables police headquarters to speak at any moment with cars anywhere in the county. Patrolling cars travelling at high specd's caii also talk with each other though miles apart. This is a distinct development upon systems whieh have been in use for some time in about 50 British cities and towns and also upon partial systems in the counties of Lancashire aird Staffordshire where hilltop stations have to ' be manned or controlled by expensive telephone lines. A feature of the new system in Hertfordshire — • ' multi-station diversity traiismissiou" as it is known teehnically — is that two unattended radio stations on hill tops at either end of the county, are operated automalieally by radio from a control point centrally situated. All messages are reeeived or brQadeast through these two stations simultaneously, with the result that they are heard clearly in all parts ot the county, including several fairiy deep valleys in the Chiltcrns. "The equipment used is compact and in Britain, not excessively expensive. Each station, equipped for both transinitting and receiving, costs about £2000 while a car may be equipped with a transmitter and reeeiver for about £150. These occupy less tlian two square feet in the luggage boot while the switches, loud speaker and hand microphone are neatly fitted to the dashboard. The use of police cars in Britain has now reached a point where the roads are patrolled for 24 hours daily. In the London area where the number einployed ^ls fairiy substantial, it is estimated that a car may reach the scene of any incident within iive minutes of the order being reeeived. In Hertfordshire where the fleet of cars is not yet complete, the time taken is slightly longer since the distances to be covered are usually greater than in an urban area. This Hertfordshire system is the first multi-station radio controlled installation in Britain. There is no comparable development in any other, part of the world.