The inspiration for this project came from Wanderlinse’s YouTube video on a similar antenna he had built.
The construction is quite simple, I bought two 900mm by 20mm pieces of wood and cut one in half. Then I made them into a cross with some brass angle brackets and wood screws.
The main loop is made of 35 turns of enameled copper wire of 0.35mm diameter (mainly because I ran out of wire at that point). The windings are 88cm across, which means that the 35 turns of wire should be about 87 meters in total wire length.
The coupling loop is made of 5 turns of 0.22mm diameter enameled copper wire.
The main loop forms a parallel resonant circuit with an air variable capacitor and some NP0 capacitors that I soldered to a female pin header so I can swap them out for different values and therefore get a wide tuning range (this works only because the loop is a receive only antenna and therefore doesn’t have high voltages present at the tuning capacitors).
Until now I’ve only had time to receive DCF77 signals (see what I did there?). This YouTube video shows the DCF77 reception with this antenna and a GNUradio flowgraph.