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9 Circle RX antenna for PI4CC

Since we are in the low sunspot its important to have a good RX on the lowbands. We don't have space for beverage antennas.
A search on the internet gives a bunch of RX antennas all with pros and cons. We want a RX antenna with good figures, no high support needed, no tuning and small as possible.

Our search stopped with the 3-in-line vertical array witch is the basic of the 9 circle array. Please read the articles in the NCJ sep/oct 2011 part 1 and in the NCJ nov/dec 2011 part 2 by John Kaufmann, W1FV. During the CDXC meeting in 2022 Tony, G2LF gives presentation on the rx-array and there is some usefull info in a Youtube video

DX-Engineering did sell a complete kit to build this array, but the stopped selling them in 2018.
As a small club station there is no money to buy a kit and we have a high DIY standard. With the on-line building instruction we decided to build an array ourself

With Eagle we design a PCB for the RX-amp, switch unit and phase unit. We put all execpt the RX-amp in one big enclosure.

To control the remote relais, we made a controller (Arduino with wifi) connect to our LAN where on is a server (Arduino with LAN) that contols the remote relais.
We can easy move the controllor from a shack to a other shack. The switch in the manual can be easily build as well.

A small example how it works is on-line. This is the basic 3 in-line east/west setup. The record is done 1 hour after sunrise.


A build rx-amp.


A look at the outdoor setup. Its well protected against the wheater.


The controllor will send over wifi to a server who will set the RX switching.


The server who will controll the outside relais. Its connected to our LAN. Its controlled via the controller above, but can also remote controled via the internet.

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