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Re: HRIT and LRIT Geostationary Weather Satellite Image Reception

Posted: Thu Jul 11, 2019 12:01 am
by RSP2user
Hi David,

The link for the original e-Bay source for the 50ft USB extender cables that were found to work well is no longer valid. Finding 50ft USB 2.0 extension cables that work flawlessly is not easy, but most that have a large ferrite choke at each end of the cable and an active repeater circuit near the middle of the cable seem to work pretty well. In ordering a second one I found that I had to ask the seller if the one they would be sending actually had a ferrite choke on each end. Some sellers have pictures that do not match the cable they are selling, so it is important to verify, before ordering one. If you search this forum for USB extender cables, you will find a number of discussions and USB solutions on the subject as well as ethernet solutions. Here is one of the extender discussions: ... der#p11513 If you are planning to locate the SDRplay RSP outdoors, you will need to take into account its ambient operating temperature and humidity range (info available from SDRplay support). The cost of a weatherproof housing may cost as much or more than a longer coaxial cable, so there are cost tradeoff considerations in locating the SDR farther form the PC, particularly if it will be outdoors. The initial purpose of mentioning a low cost USB 2.0 extender cable is that for some applications, such a USB cable can save on expensive coaxial cable costs (e.g., LMR-400, LMR-600); however, you will need to assess how helpful this will be in your specific application.

For the coaxial cable line driver, if you are using a NooElec SawBird GOES LNA with filter, these have been used on 65 ft coaxial cable runs without issue, so in many applications probably won't need a line driver. This article was first written prior to the availability of the NooElec SawBird GOES products and some of the LNA's available at the time required a line driver in addition to the LNA for long coaxial cable runs. It was also common practice at that time to have an LNA followed by a separate filter followed then by a line driver. The NooElec SawBird GOES products combine the LNA, filter, and driver and work well plus are very reasonably priced and cost typically less than a combination of separate LNA, filter, and line driver components. The SawBird GOES can be found here . The version at the link in the immediately preceding sentence can be powered directly from the Bias-T of the RSP1A, RSP2, or RSPduo and it only draws around 30mA to 40mA at 5VDC. If you find you still need a line driver, the following is an amplifier that some have applied on 100ft+ cable runs: Mini-Circuits ZRL-2400LN+, though you should check the Mini-Circuits amplifier offerings where you can likely find one better suited for your exact needs.