Original 88-108MHz Blog Broadcast FM Band-Stop Filter FM Band Reject Filter with Adapter for RTL-SDR

Original 88-108MHz Blog Broadcast FM Band-Stop Filter FM Band Reject Filter with Adapter for RTL-SDR

Description:
Includes 1x Blog Broadcast FM Band-Stop Filter and 1x SMA male to SMA male adapter.

Blocks the broadcast FM band between 88-108 MHz with over 50dB of attenuation. Insertion loss is less than 0.5 dB between 0-1 GHz, and mostly less than 1.5 dB between 1-3 GHz. A broadcast FM block filter can help if you have very strong broadcasts in your area that are overloading the SDR dongle. Also known as "FM Trap". Note, for RX use only.

Function Introduction:
This filter rejects signals between 88 – 108 MHz with around 50 dB or more attenuation. A broadcast FM band-stop filter is very useful for use with SDRs as in some areas broadcast FM signals can be so strong that they overload the SDR, causing very poor performance in other bands. You can tell if this is the case for you if you see images of BCFM stations or interference that looks like a WFM signal at other frequencies when you turn up the gain.

The filter is based on a simple 7th order Chebyshev design. The 3 dB roll off is at 76 MHz and 122 MHz. 88 MHz is attenuated by almost 60 dB, and 108 MHz is attenuated by 45-50 dB. Outside of the pass band the insertion loss is practically zero below 500 MHz, less than 0.5 dB from 500 MHz – 1 GHz, and below 1.5 dB between 1 GHz – 2 GHz. Between 2 – 3 GHz performance degrades slightly, but insertion loss remains below 1.5 dB for most frequencies. The filter can also pass up to 80 mA of DC current (probably can do more) and has negligible DC resistance.

Packing List:
* 1 × FM Band-Stop Filter
* 1 × SMA Male to SMA Male Adapter

Packaging Details:
* Weight: 0.15kg