The default
settings of the frequency control program used with HDSDR limit it to 40
MHz.
When you have HDSDR running with the receiver select the ExtIO button to
the right of the Tune frequency display. This will open another program
that is used to control the receiver frequency.
Select the Si570 tab. This will open a page showing some details of the
Si570. At the top right is "Freq range". In the right hand window change
the default setting to 300.
Click the "Hide" button.
Exit HDSDR to save the changes.
When you restart HDSDR you will be able to tune up to 70.5 MHz with the
SDR-4+ receiver.
