RADIO AND RECORDS

Radio Record, Volume I, Issue 30, 10 February 1928, Page 2

RADIO AND RECORDS

ELECTRICAL PICKUP. The combination of radio amplifiers, in electrical pickup and a gramophone is becoming increasingly popular. Most clectrical pickups for phonograph use impose less load om the record than the mechanical type, and for -this reasom a needle may be used for several records. For this reason mnumerous. ‘people have been surprised to find that the motor in the usual portable type phonograph has insufficient torque to rum some records witlt some types of pickups, although there was sufficient to run the mechanical reproducer, The reason for this is that some electrical pickups are considerably heavier than the mechanical reproducers. This weight is largely due to the use of a permanent magnet im the pickup. Since the sensitivity of such a pickup is proportional to the magnetic field strength, there is a relation between the size and weight of the magnet and the sensitivity. To make the ontput of the pickup snfticient to give loud volume on two stages, severa] mannfacturers have made units, which are quite heavy. This results im a drag on the record, and in cases where the spring motor is "weak,’" the speed is reduced, and frequently the record will ston.