Last week, I posted about Radio Direction Finding. It is an activity within ham radio which uses techniques to track down the sources of radio transmissions using radio equipment. Since it generally only involves receiving transmissions, (and not making them,) anyone…even those who are not licensed…can participate and practice these skills.
Listed here are a number of sites which have detailed plans on making a type of directional antenna that is commonly used for this activity. These antennas are known as “tape measure yagis.” You can make one inexpensively from items found mostly from your local hardware store. (I think I made mine for under $20.) If you are resourceful, I bet you can make one for even less.
This is a fairly quick project to make, and for those of you who may be new to antenna building, this is a fairly easy one as well (assuming you are comfortable with trying your hand at soldering.)
Please note that using this kind of antenna is only part of the equation for good Radio Direction Finding. One, of course, needs a good HT radio. You will also need good ears. Having an S-meter on your HT would be helpful as well. Besides all that, you will also need some way to attenuate the signal when you get closer to the transmission source. This could be accomplished by the use of an attenuator, or effective attenuation could be achieved by skill. Of course, general proficiency in using radio equipment would be most beneficial. In fact, even if RDF is the only thing you wish to do with a radio, I would still recommend getting an amateur radio license so that you can gain a better understanding of radio physics in general.
By the way, if you are a licensed ham, a tape measure yagi can also be used to transmit as well.
Here are the websites that I am recommending for tape measure yagi antenna plans:
Also, here is a good website explaining tape measure yagi antennas much more in depth:
If you take on this project, I hope you enjoy it!