A phase-coherent software-defined radio with five RTL-SDRs

May 25, 2022

May Update

by KrakenRF Inc

In this update we’ll provide details on the progress over the past month since the previous update.


Manufacturing for the most part has been completed for the first 1000 units, and over half have completed the final assembly process where the fan, thermal pads, and enclosure are put together. The final step before shipping is QC. Setting up the QC process has proven to be a bit difficult, and slow to do remotely. Usually at this stage of manufacturing a product for the first time, we would have a member of our team in China at the factory to oversee the final assembly and production. However, with COVID, this is no longer an option. Nevertheless, we have the QC processes set up and running now.

After QC is finished, units will be shipped by air to the Mouser warehouse in the USA, where Crowd Supply distribution is handled. Once the units are received into inventory, they will be dispatched to customers.

Below are some shots of the units being manufactured that some might find interesting.

We’ve also received our wonderful looking boxes, ready for packing.

Our antenna whips have also now arrived and are currently being prepared.


We have recently uploaded a new Pi 4 image to the KrakenSDR DOA Repo. The latest code adds the following features:

The Android App has also been updated and is now better optimized to work on slower Android devices. It also now adds a ‘tone’ feature which will produce a beep sound every time there is an active signal. The beep will rise and lower in pitch depending on the RF power received. This is useful for intermittent pulsing signals to indicate audibly if the signal is being received, and to get some idea on the power of the signal.

The Android App can also now handle multiple frequency channel outputs from the KrakenSDR. In the app, it’s possible to switch between channels that have received data and plot each channel’s individual heatmap and history.

Antenna Spacer

We have created a template for an antenna spacer, for use with our KrakenSDR magnetic mount antennas. The spacer will ensure that your antennas are placed at accurate coordinates for a circular array, with spacing holes every 50 mm.

If you have a 3D printer, you can use our .obj files for the individual arms and center pentagon that can be glued together.

Array Arm: Array Middle Pentagon:

If you don’t have a 3D printer our paper template can be used and glued together as well.

Array Arms: Array Middle Pentagon:

Documentation Updates

Now that we are close to shipping, documentation is the next big step we will be undertaking. As mentioned in a previous update, we have already written a paper manual, which is required for EU regulatory purposes, but going forward we will be referring mostly to our online documentation which will be on the GitHub Wiki pages.

The KrakenSDR is a technical device, and some understanding of the basic physics behind radio direction finding and/or passive radar will be needed to use the device. But, we’ll be aiming to make the documentation as simple as possible for someone with even very little background knowledge. We will also soon be working on tutorial videos.

Other Updates

Arrow antennas appear to now be shipping their KrakenSDR antenna arrays.

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