Re: Let's discuss Packard 6V electrical systems and the change to 12V systems

Posted by Peter Packard On 2008/7/2 1:47:02

G'day all, I personally haven't seen any low voltage 6 or 12 v valve mantle radio sets installed in houses in Australia, but they would almost certainly have been Automotive radio sets. Our domestic supply is 240 v ac and most early farms not connected to a domestic grid used a 32 v DC system . Mantle Radio sets (valve) in Australian households were 220-240 volts but I understand that US valve radio mantle sets at 110 volts were the ones used in cars, powered by either 6 or 12 V DC. The DC was converted to AC by a multi-vibrator, then transformed up to the 110v. (I am not sure if the high voltage portion of valve radios in European cars were 220v or 110 volts) (The valve heaters would have remained at 6v or 12V DC). The multivibrators are identical to those used in a 6V Packard valve radio. The early car radios were not very efficient and used to draw around 10 amps (6V) or 6 amps (12). Anyone who had been at the drive-in using the clip-on lead onto your 6V car aerial would attest to the two hour drain on the cars battery. I am an electrical tradesman but am not a radio technician, so some of my explanations may not be fully correct. best regards Peter Toet.