AM IF filter


Posted on Mar 18, 2013

Typical QRP receivers include Direct Conversion (DC) and simple Superheterodyne types. These receivers often have quite a wide AF bandwidth which can make inteligiblity somewhar restricted, especially under difficult QRM conditions. Many commercial amateur transcievers also suffer from this t.ex the Yaesu FT101B.


AM IF filter
Click here to download the full size of the above Circuit.

This is a simple filter that restricts the LF response a little as well providing quite a heavy HF roll-off. The prototype has enhanced a Yaesu FT101B that was only fitted with an AM IF filter. The IC is an LM358. Construction needs no detailed description. Layout is not critical.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

10-W Class A Amplifier
Infra Red Switch remote control
Nite Rider LED Lights
PC parallel port Null Printer Adapter
Touch-sensitive switch
Low-pass filter
Sample-And-Hold Circuit Ii Circuit
Automation of Lamp Relay Controlled with RF
Sensor Alarm using thyristor circuit
Long Range FM Transmitter
External protection signal generator by a circuit diagram TDA4866
2Y- connection three two-speed motor contactor control circuits
Suitable for driving the microprocessor power supply LT1587 LT1431S



Top