"Graeme" wrote in message
...
"R J Carpenter" wrote in message
...

"Graeme" wrote in message
...

Am looking for a reasonable cost BCB (MW) superhet tuner or receiver
(valve
or solid state) which has a known sensitivity of 1.0 microvolt or less
for
10 dB s+n/n ratio.

1 uV at what impedance? what bandwidth?

Assume 50 ohms input impedance, and 6 KHz receiver bandwidth (3 KHz
received
audio).

BlueCat suggested a car radio.

Car radios have had bandwidths not far different from 6 kHz for some years
now.

Let's guess that the input impedance of an automobile AM radio is 5000 ohms.
That means that 10 uV at 5000 ohms is the same signal power as your 1 uV at
50 ohms. I'd guess that a good car radio would do that ... you might have
to raid a junk yard to find a radio old enough to be "good". Especially
avoid the recent cars with an amplified AM antenna on the roof.

Bob