This unit is a small filter and preamp designed to go between the ColibriDDC software defined radio receiver and an antenna. Using a SAW bandpass filter and a low noise amplifier (LNA), it stops out of band intermodulation while providing additional gain for increased sensitivity. The LNA is placed before the SAW filter and the filter is tuned for 145Mhz. To block strong commercial FM signals a high pass filter is installed before the LNA.
The LNA used is a MiniCircuits PSA4-5043+ which provides at least 21dB of gain @ 145Mhz. To stop out of band intermodulation an 145Mhz SAW bandpass filter, which has a 7.6MHz bandwidth is also present. The overall noise figure of the unit to 0.75dB.
Connectors are SMA female both sides and the unit is powered by 5 Volt using a standard USB mini cable (not supplied). The unit can also be powered unit from a bias tee, but it is not suitable for outdoor installation unless installed in a waterproof enclosure.
- Gain min 21dB
- NF 0.75dB
- Supply Voltage USB or Bias tee 5V PCB Header 3-5V.
- Power Usage at 5V 56mA approx.
- Case Dimensions 63.5mm x 63.5mm x 30mm (2.5” x 2.5” x 1.2”)
- Frequency Response (see graph in product images)
This filtered preamp can also be delivered on request for the following frequencies:
- 137 MHz (For NOAA reception)
- 161 MHz (For AIS tracking)
- 434 MHz (70 cm band)
Contact us for any special requests at email@example.com.