SignalsEverywhere: SDR Console V3 Transmitting with PlutoSDR
Over on YouTube Corrosive from the SignalsEverywhere YouTube channel has uploaded a video showing us how to use SDR-Console V3 and a PlutoSDR to transmit ham radio voice. In the video he sets his PlutoSDR to transmit from his microphone at 445.5 MHz, and to receive at 434 MHz. He is then able to talk to a friend using a handheld who is receiving at 445.5 MHz and transmitting at 434 MHz.
Nice demo! Had no idea SDR Console supported ADALM-Pluto transmissions. I sure hope some kind of spurious emission filtering was applied to the output of the ADALM-Pluto :).
The SDR console spectrum window showed a ton of splatter coming from the Motorola XTS 5000 III at an RF power measurement of -20 dBm. I’m guessing the handheld was relatively close by and just overloaded the poor Pluto. That got me thinking …
Assuming the RF power measurement of -20 dBm is accurate; the handheld was transmitting 1 watt of power (30 dBm – lowest setting); and no extra antenna gain from the Motorola or Pluto SDR, the free space path loss of 50 dBm @ 400 MHz corresponds to a distance between the transmitter and receiver of 80 feet or so.
RF power loss is greater if the transmitter is outside and the receiver is inside of a house. In that case, depending on the building materials between the transmitter and the receiver (masonry block, plaster board, wood, etc) a building RF loss of 7 to 10 dB @ ~400 MHz is possible. So the separation distance between transmitter and receiver could have been between 25 – 30 ft. But that’s all guessing at this point.
I suppose the handheld could have transmitted into a dummy load and there would have been enough RF leakage for the PlutoSDR to receive it.
That should be free space path loss of 50 dB.
About 30′ xD you’re pretty spot on.
Correct radio was set to 1 watt and was overloading the Pluto a bit.
Thanks for the confirmation Corrosive! It also demonstrates that the SDR Console RF power measurement capability is fairly accurate. This article definitely goes into the box of tricks 🙂