Instructions on how to build a sufficient tape measure Yagi antenna, which is mainly used for fox hunting.
- 3 feet of 1/2 inch schedule 40 PVC pipe
- 3 - 1/2 inch schedule 40 cross connectors
- 2 - 1/2 inch schedule 50 caps
- 1 - inexpensive tape measure (I used a 5/8 inch wide tape, but a 1 inch wide will be better)
- 4 feet coax cable with a connector on one end (UHF, BNC, SMA, etc.) and the other end prepared for soldering
- 6 - #12 (11/16 inch to 1 1/4 inch) hose clamps (You may buy a bag of 10 and save money)
- Black electrical tape
- 5 inch piece of solid wire for hairpin tuning component (12 to 18 gauge will work)
- Hacksaw or PVC pipe cutter
- Soldering iron or gun
- PVC cement
- Electronic solder
- Wire cutter
- Flat blade screw driver or 5/16 inch nut driver (to tighten hose clamps)
Step 1) Cut an 11 1/2 inch, a 7 inch, and two 5 inch pieces of PVC pipe. Before cutting the pipe, it might be helpful to measure and mark the length using a sharpie black marker.
Step 2) Glue an end cap on each 5 inch pipe.
Step 3) Glue the two long pipes together using a cross connector.
Step 4) Glue the two remaining cross connectors on to each end of the assembly from step 3. Make sure to align the cross connectors. An easy way to align the connectors is to place them on a flat surface before the glue sets and twist them to be flat with the surface.
Step 5) Glue the two short pieces with end caps to each end of the assembly from step 4.
Step 6) Cut four pieces from the inexpensive tape measure: one 41 3/8 inch, one 35 1/8 inch, and two lengths of 17 3/4 inches. Be careful not to cut yourself on the sharp corners or ends.
Apply short pieces of black tape on each long section, and on only one end of the two shorter pieces. This is for protection from the sharp edges.
Step 7) Attach the longest (41 3/8 inch) piece of tape rule to the cross connector closest to the handle, by the 7 inch piece of pvc pipe. It will be helpful to mark the center point (20 11/16 inches) with a black sharpie marker. Position the tape over the cross connector, so the curve of the tape rule is similar to the curve on the cross connector. Center and secure the element with hose clamps on each side.
Attach the next longer element (35 1/8 inch) to the cross connector in the center of the boom in a similar fashion.
Step 8) Prepare the hairpin tuning match by completely stripping it and then the bending it into a "U" shape about 3/4 inch wide and tinning the ends of the wire.
Step 9) Scrape about 1/4 inch of paint off of the two remaining pieces (17 inch) of tape rule from the untaped ends. Tin the bare areas, then attach the hairpin match and coax wire.
Step 10) Next attach this assembly to the boom using two hose clamps.
Step 11) Secure the coax wire to the boom with a zip tie or black tape. The antenna is now ready to use.
Note Add a 7-wrap coil right under the driven element (middle tape rule) for best best performance.