Valve Radio and Audio Repair Handbook

Chapter 14

Automobile receivers

Chas E. Miller

For servicing purposes the receiving circuitry of automobile radios resembles closely that of contemporary mains powered domestic sets, and like the latter the vast majority settled into the four-valve plus rectifier superhet configuration (with, however, some interesting exceptions); therefore the same fault-finding techniques are applicable. It is in the power supply section that the two types differ because in the automobile receiver both LT and HT have to be derived from the car battery. In this respect it has to be remembered that during the vintage radio period both 6 V and 12 V systems were in general use and most manufacturers produced separate models for either voltage.

The LT presented no problem ...