NewcastleFalcon wrote:
Different radio, looks a bit more modern-may not have even needed a vibrator:)
No likely not but may have been a hybrid having both valves and transistors. Early transistors could not work well at radio frequencies but they could make good audio power amplifiers so many car wirelesses had special valves in the RF sections, ones that could run with an HT of just 12v on their anodes and be quite frugal on power, and early germanium power transistors in the audio output stages, things like the Mullard OC2x series or the Newmarket NKT4xx series... There may have en a few OC7x and 8x transistors in the early audio stages too...
Audio power transistors were a boon for the car wireless as audio output valves needed the high voltage only a vibrator could supply and they were terribly inefficient along with being noisy, both audibly and RF-wise. In the days it was hard to tell if interference was originating from the engine ignition system or the vibrator power supply...
Most of these early transistors were PNP types so suited the positive earth of the cars a treat.
None were VHF sets, strictly long and medium wave... VHF was still something of a new and scary world for wireless engineers...