Dennis Walter at Bonito has just informed me about two new product’s they’re offering: high and low pass filters. From the Bonito blog:
LP060 Low Pass Filter
The elliptically-formed low pass filter LP060 from NTi suppresses all frequencies above 60 MHz. Highly effective antennas combined with near-by strong FM stations often overburden the input of the radio and cause interference and phantom signals.
The LP060 was developed aiming at the highest possible suppression in the 88MHz – 108 MHz FM band, whereas as the 6m amateur radio band at 50MHz is still totally within the pass band. For the greatest possible effectiveness, the low pass filter should be inserted directly before the receiver input.
Attenuation values (typ.):
52MHz: -1dB
60MHz: -3dB
80 MHz: -55dB
88-110 MHz: -90dB
110-150MHz: -75dB
150-200MHz: -70dB
200-400MHz: -65 dBDimension: 88mm x 31mm x 25mm (3,46 x 1,22 x 0,98 inch)
Input and output are DC-blocked (max. 50V DC)
Attention: Only suitable for reception, high HF (>10dbm) will cause permanent damage! When using end-fed active antennas: Because the filter is DC-blocked, it has to be inserted between the receiver input and the power inserter.
Successfully tested with: Elad FDM-S1 and FDM-S2, FiFi-SDR1.0 and 2.0, PM-SDR, Winradio Excalibur, RFSpace SDR-IQ
HP0020 High Pass Filter
The elliptically-formed high pass filter HP0020 suppresses all frequencies below 2 MHz. Strong or near-by transmitters in the long- or medium wave range can cause interferences and intermodulation in the shortwave range, which can effectively be suppressed with this filter. The HP0020 filter is very steep, so that signals in the upper medium wave range are already suppressed effectively. For the greatest possible effectiveness, the low pass filter should be inserted directly before the receiver input.
Attenuation values (typ.):
<0.50 MHz:-55dB
1.0MHz: -45dB
1.6 MHz:-35dB
2.0MHz: -3dB
>2.5 MHz: -1dBInput and output are DC-blocked (max. 50V DC)
Dimensons: 88mmx31mmx25mm (3,46 x 1,22 x 0,98 inch)
Attention: Only suitable for reception, high HF (>10dbm) will cause permanent damage!
Because the filter is DC-blocked, it has to be inserted between the receiver input and the power inserter.
Click here to read the full press release on Bonito’s blog, or purchase via Bonito’s web store. I imagine Universal Radio will start stocking these soon as well.
Hi. I live near a fm transmitter (2 km) and i have adjacent channel interference on mu tuner. I wish to listen to fm reception from 140 miles away but not to that station near my place. What should i do? Do you have an idea of the type of filter i should use. Thank you.