This unit is a small filter and preamp designed to go between your ColibriDDC or ColibriNANO receiver and antenna when receiving NOAA/APT satellites in under-sampling mode. 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 137.5Mhz. 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 @ 137.5MHz. To stop out of band intermodulation an 137.5MHz SAW bandpass filter, which has a 7.6MHz bandwidth is also present. The insertion loss of this filter is approximately 1.4dB.
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 23dB
- 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)