I found an interesting page about a $20 spectrum analyser:
$20 Spectrum Analyzer for Testing FPV Systems - R/C Wireless Video: General Info, RF Gear, and Cameras - RC-CAM Forum
It contains a short demo video: sdr_2 - YouTube
It refers a/o to this page:
rtl-sdr – OsmoSDR
The page refers to a number of tuners that are used in combination with the Realtek chipset, with varying frequency ranges. The Elonics E4000 has a range of 52 - 2200 MHz, but with a gap from 1100 MHz to 1250 MHz (varies).
The Rafael Micro R820T has a range of 24 - 1766 MHz, apparently without gaps.
One of the receivers with this tuner, the "Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver, RTL2832U & R820T Tuner, MCX Input", appears to be suitable and and supports a frequency range of 25-1700 MHz:
Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver, RTL2832U & R820T Tuner, MCX Input | eBay
This seller in China offers them for as little as 10 Euro/ $ 13 including package&postage:
Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver, RTL2832U & R820T Tuner, MCX Input | eBay
More sellers:
Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver, RTL2832U & R820T Tuner, MCX Input | eBay
So that would be an extremely cheap way to get not only a spectrum analyser, but also a ham radio receiver on your desk. See the video posted above.
$20 Spectrum Analyzer for Testing FPV Systems - R/C Wireless Video: General Info, RF Gear, and Cameras - RC-CAM Forum
SDR (Software Defined Radio) technology is sweeping the ham radio community. Until recently the radio hardware was expensive. However, a bright fellow discovered that the PC-USB based DVB-T TV dongles could be turned into a very sophisticated SDR type communications receiver and the ham radio community created software to do just that. Keep in mind that these TV dongles sell for about $20 from a variety of retailers. To learn more about SDR, just google SDR DVB-T and enjoy a week's worth of reading.
So maybe you aren't interested in a affordable SDR ham radio, but don't go away just yet. I think that eventually every FPV'er wishes for some affordable test equipment that can check their transmitter's frequency, measure the relative performance of their DiY antennas, or check other RF characteristics of their video system. And they don't have $10K for a good working used spectrum analyzer. But how about $20? No doubt you are interested now!
So maybe you aren't interested in a affordable SDR ham radio, but don't go away just yet. I think that eventually every FPV'er wishes for some affordable test equipment that can check their transmitter's frequency, measure the relative performance of their DiY antennas, or check other RF characteristics of their video system. And they don't have $10K for a good working used spectrum analyzer. But how about $20? No doubt you are interested now!
It refers a/o to this page:
rtl-sdr – OsmoSDR
DVB-T dongles based on the Realtek RTL2832U can be used as a cheap SDR, since the chip allows transferring the raw I/Q samples to the host, which is officially used for DAB/DAB+/FM demodulation. The possibility of this has been discovered by the V4L/DVB kernel developer Antti Palosaari.
The Rafael Micro R820T has a range of 24 - 1766 MHz, apparently without gaps.
One of the receivers with this tuner, the "Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver, RTL2832U & R820T Tuner, MCX Input", appears to be suitable and and supports a frequency range of 25-1700 MHz:
Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver, RTL2832U & R820T Tuner, MCX Input | eBay
This seller in China offers them for as little as 10 Euro/ $ 13 including package&postage:
Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver, RTL2832U & R820T Tuner, MCX Input | eBay
More sellers:
Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver, RTL2832U & R820T Tuner, MCX Input | eBay
So that would be an extremely cheap way to get not only a spectrum analyser, but also a ham radio receiver on your desk. See the video posted above.
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