tape measure fox hunting beam antenna for HAM radio

 

 

  This is a easy to build project, It is perfect for fox hunting and emergency use.  Construction time is a bout 2 to 3 hours and the only tools you will need are a Drill, wood saw (hand or electric), Screw drivers, tin-snips, tape measure and a Soldering Iron..

Building Materials:

  One 1 inch wide tape measure you are willing to cut up.

  About 8ft. of wood  lat board or 1/2 PVC pipe (I used 1 1/4in x 3/8in wood lat board):, any thing you have or can find that is close to that size will work fine.

  Eaight really small screws. The smaller the better, If they are two wide they will bow the elements.

 Five inches 22 gauge wire for the hairpin match.

 Some RG-58 Coax, The lingth will depend if you want to put a connector near the driver element or just run a piece long enough to reach the radio. If you plan to use a attenuator with this for fox hunting I would suggest putting a connector just a inch or two behind the driver element ( check out my easy to build attenuator project here – Attenuator )

 Last but not least you are going to need some Solder and also some Soldering Flux to solder the coax to the steel tape measure driver elements.

 

Construction of the Beam:

  Firs cut the wood (or PVC) for your boom, It needs to be at least 22 inches long but if you want to atach a handle i would suggest cutting it around 25 to 30 inches long, you can always shortin it up later if needed. Next cut 3 lengths of wood or PVC at 6 to 12 inches each, These will be the supports for the elements so cut them longer if you want more support in windy days or shorter if you want it to fold up smaller for transporting. If you want to put this up as a stationary antenna at your home you can cut the supports to the same lingth as the elements and put a extra screw at the ends to hold the elements in place.

  Next mark a line down the center of the boom from end to end, Then mark a line on your supports in the middle so you can line the pieces up exactly.  Now place your support piece for the front director element at the front of your boom and attach it (use a square or something to make sure its straight), I used a Brad Nailer to attach my supports but screws or tack nails can be used ( I would also suggest a few drops of glue between them for a better hold).

  Next look at the picture below and attach your other element supports at the spacing shown, you can measure from center to center but measuring from one side of the support to the same side on the other support will work a little easier.

 

  Now that you boom is assembled its time to cut your elements, If you haven’t disassembled your tape measure do that now (wear safety glasses it could suprize you and suddenly unwind). First cut one lingth to 41 3/8 inches, then two at 17 3/4 inches and last cut one at 35 1/8 inches. Next sand the paint off the ends of your driver elements so you can solder the coax and hairpin match on, Then cut a slit 1 1/2 inches long in the middle of the element the width of the screws you are using to atach them.

  Now its time to play with your drill, First find the center of your director and reflector elements and measure out 2 1/2 inches from the center on both sides and drill a hole the size of your screws you are using (if you are using supports that are longer than 6 inches ajust this spacing to compensate).

 Next we attach the elements to the boom. This is pretty simple just center them on the supports and screw them down. I would suggest starting with the director and working back stoping to make measurements on each one to make sure every thing is straight and square. The driver elements should be spaced about a inch apart and the screws set so it can be ajusted in and out to adjust your SWR.

Hairpin Match & Coax connection:

  Cut 5 inches of 22 gauge wire ( slightly larger wire will work to, I have seen people use striped house wire and it worked fine), Next bend it into a loop about 3/4 inch apart. Now heat up your soldering iron.

  Cut your coax to the lingth you desire and strip the end being connected to the beam. By now your soldering iron should be hot and you can solder the coax and hair pin match on (see picture below).

 

 

 

 

  Now the main part of your antenna is finished, All thats left is to make a handle and add any other modifications you want to make.

  Below are some pictures of my completed beam….