AM and FM Band Reject Filters
Posted: Sat Jul 20, 2019 4:31 pm
Many SDRplay users live near AM and FM stations and find that these strong signals have a detrimental effect on reception with their RSP. In some cases the built-in AM and FM filters are not sufficient. There have been numerous posts recently on how to build filters to reject unwanted signals. If one does not have the skill or inclination to build something there are several off the shelf options that may be purchased at low cost. I like the NooElec products and they are available for the very reasonable price of £10.
The AM filter has some nice features:
- Rejects AM band but passes LF and HF signals
- It will pass DC so bias-T will still work
- Fully shielded
- ESD protection
- 3 dB rolloff at 350 KHz and 1900 kHz.
- Up to 40 dB of attenuation
Can be purchased at Amazon: https://tinyurl.com/amreject
The FM filter has the following features:
- Rejects FM band but passes signals above and below
- It will pass DC so bias-T will still work
- Fully shielded
- ESD protection
- 3 dB rolloff at 80 MHz and 115 MHz. (Much sharper than the RSP built in filter)
- Up to 40 dB of attenuation
Can be purchased at Amazon: https://tinyurl.com/FMreject
I own both of these products and have been very satisfied. Both come with an SMA coupler so they are very easy to connect to your RSP.
Bill
The AM filter has some nice features:
- Rejects AM band but passes LF and HF signals
- It will pass DC so bias-T will still work
- Fully shielded
- ESD protection
- 3 dB rolloff at 350 KHz and 1900 kHz.
- Up to 40 dB of attenuation
Can be purchased at Amazon: https://tinyurl.com/amreject
The FM filter has the following features:
- Rejects FM band but passes signals above and below
- It will pass DC so bias-T will still work
- Fully shielded
- ESD protection
- 3 dB rolloff at 80 MHz and 115 MHz. (Much sharper than the RSP built in filter)
- Up to 40 dB of attenuation
Can be purchased at Amazon: https://tinyurl.com/FMreject
I own both of these products and have been very satisfied. Both come with an SMA coupler so they are very easy to connect to your RSP.
Bill