RadioBanter - View Single Post - Sangean ATS-909 external antenna impedance??

Lostgallifreyan · December 24th 09, 08:56 PM posted to rec.radio.amateur.antenna

JIMMIE wrote in news:a189b33a-452f-4dd7-8f82-
:

Ive measured the input impedance of a few SW receivers and found them
to be in the 1Kohm ballpark for the most part. I did this by applying
a voltage through a series resistor to the frontend of the radio and
adjusting the value of the resistor until the voltage dropped by 50%.
If you have a schematic an analysis of the front end circuit might
give you and idea.

Ok. That fits with the 1K pot for RF attenuation in that radio, someone
mentioned this and I wasn't sure if other parts might alter the picture, but
I guess not by anything that matters. I'll be using a ferrite at the radio
end of a balanced line so I guess I can experiment with turns count and watch
the signal strength meter. Might not even need a preamp if that works.

If I'm thinking wrong, please stop me before I crash into something.