Build Log: M1 Transceiver: 9mhz Notch Filter, IF Attenuator, and IF Amplifier

Saturday and today I finished up these two modules. The 9mhz trap is [supposedly] required to suppress the 9mhz BFO and external 9mhz frequencies from the IF. I calibrated it with my Rigol DS815, it provides 57db of attenuation at 9mhz.

 

m1 txvr att and if amp