Lostgallifreyan wrote:
Does anyone know what the Sangean ATS-909's external antenna input impedance
is?
SNIP

What I really want to know is whether the ATS-909 will work ok with a
long(ish) wire outside feeding a 50 ohm coax via a 9:1 transformer, or if
that would cause more bother than connecting a wire directly to it and
putting up with local noise picked up from nearby buildings.

There's a 1K0 pot across the input which is used as a cheap and cheerful
RF gain control. So i'd assume about 1K. You wouldn't have a problem
with the wire attached direct, but you'll get lots of front end
intermod, as it's wide open - just a low pass filter (presumably 30MHz
cut off)before the RF amp. A bit of preselection is pretty necessary for
an external wire of any size.