LNB tests – indoors

With the bias tee providing 12V down the LNB feed it was time to set up and test things. My plan is to see if I can receive signals from Es’hail 2 with a really simple system, consisting of the 60cm dish plus LNB, an RTL-SDR dongle, and a Raspberry Pi running Gqrx.

I have already used the RTL-SDR plus Raspberry Pi setup to receive Funcube in the 144MHz band, so had the software already set up (fortunately I always document how I do stuff, otherwise I would never have remembered how to set it up!). Here’s a screenshot of the system looking at a test signal on the LNB:

Screen grab with Gqrx running
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Prep for geostationary tests

I’ve had no time to make proper progress on the deep space project recently. However the launch of Es’hail 2 in November made me think about another step along the way. I have a steerable dish (even though it’s not yet computer controlled), so I can steer it towards geostationary satellites easily!

The Es’hail beacon and transponders will allow for some useful tests; and Brian GM8BJF gave an interesting talk at the Lothians club recently showing how it could be done. So the first step is to make a bias tee for a LNB:

Bias tee for LNB

I found a useful screened box on the IF section of an old microwave unit, and have made a very simple bias tee to squirt 12V up to the LNB.

Continue readingPrep for geostationary tests