Modifying the Outernet LNA for Iridium Reception
A few days ago we posted a review on the Outernet LNA which can can be used to help receive their new L-band service signal. Their LNA uses a filter which restricts the frequency range from 1525 – 1559 MHz as this is the range in which the Outernet signals are located.
By default this LNA cannot be used to receive Iridium because the pass band on the default SAW filter does not cover the Irdidium frequency band of 1616 – 1626.5 MHz. Over on Reddit, devnulling decided to experiment with one of these LNA’s and see if he could replace the default SAW filter to enable Iridium reception. In his post he shows how he removes the default SAW filter, and replaces it with a Murata SF2250E SAW filter, which is the same size, but has a center frequency of 1615 MHz and a bandwidth of 20 MHz. Iridium is used for data services like satellite pagers, and with the right tools can be decoded.
We are also curious to see if this LNA could be modified to be used with GOES reception, which occurs at 1692 MHz.
Note: For those who had trouble with obtaining international shipping on these LNA’s the Outernet store now supports USPS international shipping, and NooElec appear to now be selling them on their site directly. Their products can also still be obtained on Amazon for US customers.
Additional Note Regarding the Downconverter: Also, it appears that the Outernet downconverter prototype that we posted about back in May has unfortunately been discontinued indefinitely and will not enter mass production. For now the LNA is the best option for receiving their signal.
it uses the MAX12000 GPS amplifier … according to the datasheet the first amplifier could be a good amplifier for anything from 1450-1800 if you find the right filter
but with a gain of around only 17.5dBm
using the second amplifier your range narrows to about 1550-1750 at another 14-16.5dBm (depending on setting)
so if you want to try and find a saw filter this could be good for anything in that range
im sure you can just stick in a high pass filter or even a short and deal with some interference for your GOES or NOAA