Older articles:

1. LNA teardown

   Receiving radiosondes is very easy, provided that you have line-of-sight to the balloon. Any mountains, buildings, trees, or any other obstruction will block the radiosonde signal. If you're close to a launch site, you don't need an expensive antenna or LNA, so save your money and buy dinner for a fellow sonde chaser after your next successful recovery.

   Low-Noise Amplifier

   If you live within 200 km of a radiosonde launch site, or have line-of-sight to the balloons up in the air, you don't need a preamp/LNA. Standard RTL-SDR dongles are sensitive enough to receive the 60 mW radiosonde transmitter out at several hundred km away, even with 50 feet of RG-8/LMR-400 coax and a splitter.

   But maybe you're ...

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2. Building a Quarter-Wave Ground Plane Antenna

   After my talk at Pacificon a few months ago, several people reached out to me about setting up a radiosonde receiving station at their house. They specifically had questions about the antenna and LNA, and after answering the same question a few times I decided to do a post about this topic.

   Building a 1/4 wave ground plane antenna is very easy to do. The overall design is simple, with a vertical element surrounded by a ground plane consisting of two or four wires bent down. Here are the dimensions for the VHF/UHF amateur radio bands (from the ARRL Handbook), but these dimensions can be scaled to any frequency.

   

   There are many online calculators that will give you ...

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