Starting with City 27 Mhz band at 16y old, my first projects were DX antennas Delta Loops then I made several antennas for my QTH and also for my friends in Milano and Bergamo, during my 35y ik2nbu licence.

I also built a Big Gun Quad Antenna:
Radiokit magazine Super Quad by ik2nbu

Many projects are also available for portable antenna use on Moutains during Watt for Miles QRP Activity

Mix Antennas Projects:
Big Gun HF Quad
Vertical 10-15 Mhz with Tuner
PDF ideas from Radioavventura
SOTA Antennas
Vertical Ringo 27 modified for 14 Mhz
Warc Bands Vertical Antenna
Magnetic base SMA Antenna and RG174 Cable
Circuits and Balun
Simple Phase Antenna Circuit
Balun Calculator Comparison
Half Wave Wire Tuner
7 mhz Half Wave Wire Tuner
Wire HF Antenna Calculator
Loop and Active SWL Antennas
OM an SWL 90 cm Tuner Loop
Active Loop 60 cm Preamp
Loop Matching 14 microH
BCL Table Loop 50 cm
Loop 19 microH for OL and OM
Mini Whip by ik2nbu
L Trans-match Medium Wave Wire