William Sommerwerck wrote:
I'm guessing that the 7.5V specs are for the lowest voltage the designers
felt gave acceptable performance.

I feel that Grundig assumed the service person would connect
their bench supply between rail ground and 'battery +',
*not between 'battery -' and 'battery +'*.

Unfortunately, they call 'power rail voltage' and 'battery
voltage' the same thing. They are different by 2 V in MW mode!



--Winston