Hi.
A front-end preamplifier schematic borrowed from the web with a very large input impedance is connected to an antenna at 'signal in'...



For best performance; should the antenna output impedance match the ~1MΩ for the circuit ? There is no tuned circuit. Will it receive a very wide band RF signals ?

 

Will it receive a very wide band RF signals ?

Or will it just pick up mains hum?

 

Hi.
A front-end preamplifier schematic borrowed from the web with a very large input impedance is connected to an antenna at 'signal in'...

View attachment 365888

For best performance; should the antenna output impedance match the ~1MΩ for the circuit ? There is no tuned circuit. Will it receive a very wide band RF signals ?

It will receive all the signals and noise that you see if you connect an antenna to your oscilloscope input!

 

This is what I use. To be honest, the front end is tuned with a tuning capacitor across L1. It should still work for broadband reception.
L1 and L2 are hand-wound coils wrapped on toilet cardboard rolls, one slides into the other in order to adjust the coupling.

 

Thanks.
What circuit added at the FET input would reject WiFi and mains; allowing 50 MHz to 600MH to pass keeping a very high FET input impedance ?

 

What is the WiFi frequency?

 

Both. 2.4 and 5 GHz and any all others on Wifi. Mostly all frequencies above 1GHz, blocked.

 

There is no tuned circuit. Will it receive a very wide band RF signals ?

No, this is a low frequency amplifier. A frequency range of 50-600MHz is unrealistic.