![]() ![]() The principle is quite similar to leaving a 1Mohm input oscilloscope input floating. The basic principle is to use a very high input impedance voltage amplifier with a relatively small electrode to pick up the signal. HFoF Antenna, test install Mini-Whip Amplifier DesignĪs should be well established, a Mini-Whip is the name of a specific type of broad band E-field antenna. The final implementation uses the housing from a PCtel GPS antenna that can be bought quite cheaply from China, and a custom 4-board vertical stack of electronics. To resolve these issues I did some design work on the basic mini-whip design, and I decided to use fiber optic transmission (RF over Fiber) for the RF output since I had a bunch of suitable fiber coupled laser diodes sitting around. Others as needed, both permanent and temporary.Distribution to multiple devices is problematic because of ground loops, especially when computers are involved.Ground loops causing mode conversion and HF noise. ![]() Slightly higher than needed input capacitance due to lazy design.Lack of front end low pass filtering causing desensing and intermodulation when VHF+ transmitters are active.My existing Mini-Whip implementation has a few issues that I wanted to correct in my new design. ![]()
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