New RTL-SDR gear

I’ve played with these RTL-SDR sticks for several years now and I am still amazed about the possibilities I have with these cheap pieces of hardware. I managed to receive several data modes like ADS-B, ACARS, AIS and the wireless outdoor thermometer of my neighbor – I’ll write several follow-up posts on this topics 🙂

I decided to get two new Sticks for my collection – this time with a TCXO oscillator to get a more stable reception.

Modified Stick? Whats the deal?

Shift over time (source: rtl-sdr.com)
Shift over time (source: rtl-sdr.com)

A common problem for these sticks is frequency stability over time. As the oscillator is heating up under load, the frequency of the crystal measured in ppm (parts per million) will change – which causes the frequency to shift. Typical values for cheap sticks are +-150ppm. The real amount of frequency should could be several kHz, which make this behaviour really annoying for headless receivers (like ADSB receivers on a Raspberry Pi) – especially if you try to receive a narrow signal.

 

 

 

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