On Wed, 15 Sep 2004 11:08:21 +0200, Toni
wrote:

Hi,

I have a Sony radio for SWL and I have seen that if I parallel a
300 ohm resistor to the antenna input the received signal drops
considerably [1]. I think this means the receiver's input
impedance is much greater than the normal 50/75 ohms. This makes
me wonder two things:

- How can I measure the approximate value of the receivers input
Z?

Normally done with a noise bridge.

Am scratching my head what to do, if there is no noise bridge....

w.