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Field day with a DSP receiver

· 2 min read
Marcelo Gadotti
Marcelo Gadotti
Software Engineer

On the weekend of the 2024 CQ WPX contest, I decided to take the opportunity to do a quick SWL field day with my new ATS-20+ receiver, to test its reception in a low-noise location.

Even though it is an extremely simple receiver, based on the Si4732 integrated circuit — a DSP receiver with few external components —, reception on HF was already looking very promising using a telescopic antenna. For the field day, a 3 m long wire was connected directly to the BNC connector.

ATS-20+ receiver on the table

Internal view of the ATS-20+, showing the Si4732 board and the Arduino Nano

For the tests, I chose the Franz Damm municipal park, better known as the Botanical Garden, in the city of Timbó, SC, which has a green area with several shaded picnic tables.

Field day setup on a picnic table at the Timbó, SC Botanical Garden, with the ATS-20+ and the wire antenna

In a location with a noise floor close to zero, reception on the 10 M and 20 M bands exceeded expectations during the CQ WPX SSB contest. On the 49 M broadcast band, I was able to receive Rádio Nacional da Amazônia on 6180 kHz — something I had never managed at my own QTH due to the high noise level.