Michael Black wrote:

The wording "external DC supply" versus "AC power" makes me think
that he thinks he's comparing apples and oranges. Unless he's
talking about running it off batteries, an "external DC supply" runs
off AC and is the same thing as "AC power".


Even then he could have more noise from batteries due to the internal
resistance of the battery causing poor regulation, and noise picked up
on the wires that connect the battery to the radio.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida