40 m Band Direct Conversion Receiver


Posted on Dec 17, 2012

Building a practical and usable direct conversion receiver for the 40 m CW band is not as simple as it might appear. Broadcast station signals from the adjacent 41 m band, will easily overload most direct conversion mixer designs with their unwanted (and quite nearby) S9 +40 dB signals. My solution incorporates a diode-ring mixer and a narrow band rf input filter. These choices result in observed overall receiver dynamic range than that experienced when using an IC mixer module (such as a NE612).


40 m Band Direct Conversion Receiver
Click here to download the full size of the above Circuit.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Arduino multi-mode lamp with soft touch switch
simple bus level-shift / I2C mosfet level converter Fairchild BSS138
digital step km counter with
enhanced 4 digit alarm
the Poppet 500 milliwatt AM transmitter
AT89C2051 Night Light Saver
Mini USB-DMX interface
peltier_mod
Music Equalizer Display Circuit
A typical circuit for the LM4916 two-channel amplifier



Top