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Exploring the RSP1A SDR

Intro

The RSP1A is a small yet capable software defined radio selling for about $120 in 2023.

I used the SDRConnect software on two different laptops.

  • Laptop 1 – 2021 MBP M1, 32 GiB RAM
  • Laptop 2 – 2018 MBA Intel 1.6 GHz dual-core, 8 GiB RAM

Run Modes

The software can run in application or server mode.

Application mode presents a user interface for controlling the SDR device. It has controls for band visualization, frequency selection, audio filtering, recording, and more. It presents the option to connect to either a local RSP1A device, or to another software instance running in server mode.

I was also able to tunnel the client/server connection across an AWS EC2 instance using port-forwarding over SSH from both laptops to the cloud instance. Client/server mode uses significant bandwidth and works best on a local network. I’m using a symmetric Gigabit internet uplink from my apartment.

Server Mode

Starting server mode from the command line:

cd /Applications/SDRconnect.app/Contents/MacOS/SDRconnect/
./SDRconnect --server --help
./SDRconnect --server --port 50000 --samplerate 5000000
Built-in help command doc

Built-in help command doc

Server mode at 5 MSPS

Server mode at 5 MSPS

Application Mode

Dual VFOs with waterfall display

Dual VFOs with waterfall display

Device Settings

Device Settings

Display Settings

Display Settings

Remote server connection settings

Remote server connection settings

SSH Port Forwarding

First configure a reverse tunnel from the public VM to the SDRConnect server. Then either configure a proxy on the public VM or setup another SSH tunnel.

ssh-copy-id -f -i ~/.ssh/id_rsa_shane_mba_13.pub ubuntu@quartz.bstk.co
ssh -fNgR 50000:127.0.0.1:50000 ubuntu@quartz.bstk.co  # from server
ssh -fNgL 50000:127.0.0.1:50000 ubuntu@quartz.bstk.co  # from client
nc -vz localhost 50000

Superhet vs SDR