New answers tagged

1

First of all, the properties of an antenna are far less important for receiving than transmitting. To receive anything at all, just about any piece of metal will do. That said, the lower the frequency (longer wavelength) you want to receive, the larger the antenna should be for it to work well. Once you get into the “HF” range (below 30 MHz, formally, but ...


1

If your signal was at 500 MHz, and you successfully captured it with a 6 Msps sample rate, the signal is no longer "at" 500 MHz. Indeed it was transmitted there, but either: your receiver has an analog mixer, and mixed this signal down to baseband such that it could be sampled at 6 Msps, or the digital signal was originally sampled at a much higher rate, ...


0

If the question is about how to solve this RFI/EMI issue, here's what I did to partially reduce the problem: I put chokes (multiple turns thru ferrite toroids) on every wire and cable connected to the Raspberry Pi(s) being used for HF (AirSpy HF+, SDRPlay, Lime Mini, et.al.). These cables are possibly being used as antennas by the on-board DC-to-DC voltage ...


1

The "Frequency" is the center frequency of the signal the block produces. The "Freq. Corr." is a value in "parts per million" that the frequency is multiplied by, to correct for tuning inaccuracy separately from specifying the intended frequency. That is, the frequency sent to the hardware is $$\text{Frequency} \times \left(1 + \frac{\text{FreqCorr}}{...


2

The data is AM modulated on the 2.4 kHz subcarrier, with 256 different levels representing a single value from 0 to 255. It's a scanline every 1/2 second from the cameras with sync and telemetry data added to the beginning and end. Each line is 2080 data points (words) long, so it broadcasts at 4160 baud. The sync lines at the beginning let you know when a ...


Top 50 recent answers are included