Final BW - A Minimal Software-Defined Radio VHF_UHF_SHF Transceiver.pdf
Presentation Slides
hisenzhang01 at gmail dot com
Field operation using log periodic antenna for 902MHz-5706MHz.
A conventional rover kit comprises a 2-meter radio, transverters to different bands, power amplifiers, and power supplies. The complete set of equipment is bulky and massive given its complexity, which further raises concerns about system robustness. It’s not uncommon to find the equipment fails before or in the middle of a contest. How discouraging that sounds.
This project, however, intends to improve robustness by simplifying the conventional setup. The philosophy is “one part fits all, " or “wideband” in radio terminology, implying that only a minimal number of parts shall be used in order to lower the chance of failure. To sum it up:
While not intended, a side benefit from the above goals actually made the kit very affordable. Refer to the Parts section.
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Block Diagram
The SDR hardware, program, and additional scripts together replace massive conventional radio and transverters and their power supplies. BPF manual switching uses SMB snap-on connectors.
The complete set of equipment.
The current experiment setup includes one box of filters and cables and another of tools and instruments, in addition to a tripod and antennas hiding in the shadow. For contesting, everything will fit into one crate. A laptop sits on the boxes just fine. The yellow lid crate contains irrelevant car maintenance stuff, but the clipboard fits in the lid very well :)
The clipboard
The SDR hardware and control circuits are mounted on a clipboard with 10-inch bungee cords, binder clips, and 3M tapes. Of the two used ports, the one on the left is Rx, and the right is Tx chained with a PA. Then they merge into an SPDT switch to share BPF and antenna.