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3B7A – 1st Major all-SDR DXpedition

3B7A Antennas SetupThe 3B7A Saint Brandon team is now active from Saint Brandon and we are exited! This is the first major DXpedition that will be using only SDR transcievers in its setup. No old-school analoge radios, only the latest SDR technology in an amazingly portable but potent package! Read the full story here!

Using past experience from their successful FT4TA expedition to Tromelin island and FT4JA Juan de Nova island Expedition, the experienced team lead by F5UFX Seb build their St Brandon setup around the SunSDR2 PRO transceiver, the SPE 1.3K-FA amplifier and ModMic attachable boom microphone.

3B7A Station Layout
3B7A station layout based around the SunSDR2 PRO HF, 6m & 2m SDR Transceiver.

3B7A will have 5 x HF stations on air simultaneously. Each station will have a SunSDR2 PRO with E-Coder hardware controller, an amplifier, and a ModMic. Logging is done using WinTest in network configuration and all stations will be able to operate CW, SSB or RTTY.

3B7A Test Setup
Test run of 3B7A operating positions with SunSDR2 PRO, E-Coder hardware controller and laptop for logging.

All 5 stations will have will have identical configuration from the keyboard to the amplifier. This will keep the operator focused on the pile-up and improve redundancy in case of any equipment failure.

In order to maximize the antenna configuration of the location and more specifically the proximity of the ocean 3B7A will use their classic VDA, Vertical Dipole Arrays, that have proven to give excellent results on the beach on low bands vertical mono band antennas will be used together with RX antennas to separate weak signals from the static noise. To minimise interference between stations 3B7A are using Low Band Systems PerfoBox band pass filters.

3B7A uses their ModMics in a very clever way; a microphone is permanently connected to the radio at each operating position. When it is time for operator change the mic is simply detached from the headphones of the leaving operator and handed over to the next operator who easily attach it to a pre-fitted magnetic clasp on his headphones. Personal settings in SunSDR2 PRO then allows for customised microphone equalisation, processing level, noise gate and RF clipping to optimise for each operator’s individual voice characteristics.

Disclaimer: supports 3B7A with equipment support and the operator/owners of has personally also contributed financially to the 3B7A DXpedition. You can support 3B7A too, just visit their donation page at 3B7A Saint Brandon DXpedition.

We wish the team F5UFX, F5CWU, F4BKV, F4FET, F2DX, F5PTM, F4HAU and F8ATM GL and huge pileups!

Track the 3B7A team on their journey to Saint Brandon here.