RTL-SDR Blog - NOTCH FILTER 88-108 MHz

In stock

Old price 29.95 €

24.50 €

You save 18 %

Price incl. VAT, plus delivery

Available delivery methods: STANDARD delivery WITH INSURANCE, Pickup by customer in our physical shop, STANDARD DELIVERY IN ITALY, HEAVY (over 10 kg) OR BULKY GOODS - ONLY FOR DESTINATIONS IN ITALY!, HEAVY (over 10 kg) OR BULKY GOODS WITH INSURANCE - ONLY FOR DESTINATIONS IN ITALY!, EUROPE 1 - SMALL PARCEL (UP TO 10 KG) - NO INSURANCE, EUROPE 2 - LARGE / LONG OR OVER 10 KG PARCEL - NO INSURANCE, EUROPE 1 - SMALL PARCEL - (UP TO 10 KG) - WITH INSURANCE, EUROPE 2 - LARGE / LONG OR OVER 10 kg PARCEL - WITH INSURANCE, CORRIERE STANDARD ISOLE MINORI E VENEZIA LAGUNA, CORRIERE MERCE ASSICURATA ISOLE MINORI E VENEZIA LAGUNA (fino a 10 kg)

Description

RTL-SDR Blog - 88-108 MHz NOTCH FILTER FOR RECEIVERS - DRASTICALLY ATTENUATES THE SIGNALS OF THE FM 88-108 MHz BAND

ATTENTION: ONLY FOR RECEIVERS !! DO NOT USE IT WITH TRANSMITTERS.

The filter comes in a 2.8 cm x 2.8 cm x 1.3 cm aluminum enclosure and uses female SMA connectors on each end.
Included in the package is also a SMA male to SMA male straight barrel adapter.

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.