Go to your local library and get the ARRL Antenna Handbook, it covers antennas extensively and has lots of antenna designs and the formulas to calculate what length to make your antenna.
It’s a great book for those of us that love to play with radios.
WARNING & DISCLAIMER:
SELECT AND USE OUTDOORS AND SURVIVAL EQUIPMENT, SUPPLIES AND TECHNIQUES AT YOUR OWN RISK. Information posted
on this forum is not reviewed for accuracy and may not be reliable, use at your own risk. Please
review the full WARNING & DISCLAIMER about information on this
site.