Dear Sir,

This TA2003P SW receiver corcuit only can tune in the frequency range from 6 Mhz to 10 Mhz, may I know how to modify the circuit to allow it to tune in from 4 Mhz to 30 Mhz?

Thank you

 

I used the wrong preamplifier on an antenna and could hear most of the Harmonics from other bands.
You could call it a down converter. This preamp is usually used with an oscilloscope.
The preamp was wideband, it had a few cascaded low noise mmics and some capacitors.
I am sure you could make it better. If the receiver is centered 14-15MHz you could use
both up and down conversion. Some do not accept that harmonics can be useful.
They seem to be narrow banded discussing radio design, digital up/down converting is doing incredible things.

 

To shift the frequency coverage you would need to scale the local osc inductor and caps and the antenna inductor and cap to the desired frequency range. You need to read a bit about radio IF (intermediate Frequency), essentially the antenna frequency is either added or subtracted from the local osc. frequency and the result is the demodulated/detected and amplified by the audio amplifier.

 

Dear Sir,

This TA2003P SW receiver corcuit only can tune in the frequency range from 6 Mhz to 10 Mhz, may I know how to modify the circuit to allow it to tune in from 4 Mhz to 30 Mhz?

Thank you