20/40 Trap Antenna
Whilst the End Fed is convenient aerial as only requiring a single point and the squid pole, it has never performed as well as a dipole.
With the marginal conditions we have experienced as of late my thoughts wandered to going back to the dipole.
I converted my original dipole to a 20/40 trapped dipole rated at 20w. This works very well but a heavy unit with 18G automotive wire and 10m of RG58 coax. Always in the search for lighter options so decided to make a trapped dipole using lighter traps and wire. I always use a balun at feed so also seeking lightweight options.
SotaBeams releases a range of ‘PICO’ traps and light balun kits rated at 5W. As my activations are within this range, it was obvious what was next. Still had some ‘Unicorn’ wire stashed away so ordered the Pico traps and Balun from SotaBeams and waited for delivery.
Here is the finished product. There is not much to see as PICO is the operative term. Note the lack of bend in the 7m heavy duty squid pole.
Making the Balun consists of twisting the wire, winding through the toroid then attaching the coax. Quick check to ensure all connections are good then turn attention to the traps. Instructions for – PICO Balun.
Traps took a lille more time. Only because it pays to get it right. I had to add a extra turn to the instructions to get resonance as 15 turns were too low. Decided to use ‘Liquid Tape’ to protect the units instead of wrapping heavy tape around the units. Instructions for – PICO Traps.
Once done its time to assemble the antenna. Straight forward process. Attach 5.5m of wire to balun and take outside setting up on the pole and carefully trimming the wire until happy with 20M legs. Once completed attach the traps check, then add another 5.5m of wire and trim down until 40m is right. 5.5m is a bit long for 40m as the traps load the leg so next time will start with 5.1m legs.
With 10m of RG174 and a winder, the dipole comes in at 260g. Still heavy so may take 3m out of the coax.
Initial tests are very positive. Time will tell as to durability but happy with the result so far.