If you use 6 x AA NiMH rechargeable cells you can have 2A/Hr rating which
means they will outlast even the best pp9 the overall voltage will be lower
but it shouldn't affect the audio.

--
Pete Cross

"Owain" wrote in message
...
Paul D.Smith wrote:
FYI, the R505 has a battery compartment only just big enough for the PP9
and
therefore too small for the "6 x C cell" adapter that they cell. I
believe
that a commercial 6 x AA cell would work, but not for very long because
AA
cells are low capacity.

If the batteries don't have to be *inside* the radio, you could get a
battery box (from Maplin) holding Cs or even Ds, as well as PP9 battery
clips. The battery clips would need to be soldered to the battery box
leads the *wrong* way round, so the stud on the battery box clip mates
with the claw on the radio's clip.

The angry wasp syndrome is probably due to poor smoothing and
suppression on the power supply rather than (voltage) regulation. It
might be possible to add better smoothing/filtering to whatever PSU
you're trying.

Owain