Can anyone help with a circuiot please?
I'm trying to recieve the weather satellites around 137Mhz, but VERY close to me are pagers on both 138Mhz and 153Mhz and they totally swamp the wanted signals out
I want to build a notch filter that will notch the following frequencies (make them inaudable)
137.175Mhz with a 200Khz bandwidth
138.850Mhz with a 200Khz bandwidth
and also one for 153.275Mhz with a 300Khz bandwidth
Ideally I;d like to make them all as one unit, but it I have to make several filters I wont mind.
Can anyone help with circuits please?
I did think about coax stubs but it wouldn't "notch" the signal enough
Lewis
I'm trying to recieve the weather satellites around 137Mhz, but VERY close to me are pagers on both 138Mhz and 153Mhz and they totally swamp the wanted signals out
I want to build a notch filter that will notch the following frequencies (make them inaudable)
137.175Mhz with a 200Khz bandwidth
138.850Mhz with a 200Khz bandwidth
and also one for 153.275Mhz with a 300Khz bandwidth
Ideally I;d like to make them all as one unit, but it I have to make several filters I wont mind.
Can anyone help with circuits please?
I did think about coax stubs but it wouldn't "notch" the signal enough
Lewis