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Active Antenna Amplifier Loop Configuration

loop configuration

Active antenna amplifier loop configuration provides a whole range of interesting choices. I am going to try the dual crossed loop setup.

The commercial LZ1AQ kit provides connections for two loops and a short electric dipole. You also have control circuits for switching between various configurations.

When you read the instructions, Chavdar provides a number of suggestions for different configurations. You can read these yourself and look a pictures of what other users have accomplished. You will find comprehensive descriptions and instructions on how to build and mount these loops.

When I considered my options for AAA-1C antenna configuration, I decided to go for two loops in one plane, as shown above. This will provide me with the option to use two loops crossed in parallel. The benefit of this configuration is my ability to reduce loop inductance by half. The lower the loop inductance, and the greater the loop area, the better performance for signal strength.

My experimental mounting structures are 1½ inch ABS (plumbing) pipe in 3 foot lengths, shown above left. When mounted, the center of my dual loops will be about six feet above ground. The amplifier will be held onto the ABS pipe, with polarized wiring to the two loops.

This setup should reduce my loop inductance down to the 2 μH range, and provide a 6-8 dB signal gain over a single loop. Each wideband loop is 1 meter diameter aluminum PEX.

Active Antenna Amplifier Loop Configuration Plastic Structures

Of course, I used my 3D printer to make the mounting structures, in two parts. First, shown lower right, is the actual loop mount. My experimental approach uses compression fit on the PEX pipes, which works quite well for a solid mount. The holes are the same size as the PEX outer diameter and the loops fit snuggly. Connecting wires are tightened down onto bare aluminum with screws and nuts.

Second is my bracket to mount the antennas onto the ABS pipe. Compression fit is used to connect the bracket to the pipe. Screws and captive nuts hold this bracket into the loop mount, as shown top right. Wires exit small holes in the mount. Everything can be sealed easily with silicone once assembled.

PETG is my filament of choice and will hold up well across broad temperature ranges outside. Tolerances are close for compression fits, and my new Prusa MK3S 3D printer does everything well.

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