“Tigertail” HT Counterpoise

by Chad Rudolph, W1CAR

The idea here was inspired by many other amateurs including Ed KE4SKY and Virginia RACES

These parts can all be found at Wal Mart or any hardware store. I found them in my garage.

– about 20″ 14-18 gauge stranded copper wire, or equivalent (smaller gauge = easier portability)
– 5/8″ hose clamp (fits BNC well, although larger will work if cut or shortened)
– solder

– wire strippers / cutters
– soldering iron
– straight screwdriver
– Dremel with grinding or sanding bit (optional)

(1) Cut the 18 gauge wire to 1/4 wavelength of the designated frequency, for this example I used 19.25 to 19.5″ for 2 meters (and this also works well on 440mhz). Strip 1/4″ of the insulation and twist the fine copper to keep it from spreading apart.
– For 220mhz, use 11.5″ and for 440mhz, use 6.5″
(2) Gauge how you want the hose clamp to seat on your BNC connector first, and tighten it to get an idea where you will solder the wire. Mark it with a pencil, then use a Dremel tool (optional) to sand a spot so the solder will hold to the clamp.
(3) Lay the wire on the clamp or even run the copper through one of the openings on the clamp, but not too much. Solder the wire to the clamp and let it cool. Pull slightly to make sure the wire is firmly attached.
(4) Attach the hose clamp to the BNC connector, and tighten it so that it doesn’t slip off accidentally, but don’t over-tighten and damage the BNC connector.

Theory: (KE4SKY’s explanation here)
– The idea is that an HT using a “rubber duck” has -5db gain compared to a quarter wave antenna that is held at shoulder height. Speaking in terms of effective radiated power, a 5 watt HT with rubber duck antenna held at shoulder height is actually only radiating 1.5 watts on key-down. The stock antenna is a horrible radiator, and it lacks a counterpoise or a ground plane to keep the RF from coupling to your body. Similar to using a 1/4 wave mobile mag-mount and not mounting it to a metal surface.

– By using a Tiger Tail counterpoise, you give your HT a missing lower quarter wave and along with a quality aftermarket antenna (flexible 1/4 wave or telescoping 1/2 wave) you succeed in creating a center-fed half-wave vertical dipole, giving the HT much much more effective radiated power. The Tiger Tail can be left to dangle, but is directional and the radiation pattern can pointed in the direction of the station you are attempting to contact for better results.

– I’ve seen these talked about many places on the internet, and most say to use a battery clip to connect the Tiger Tail to the BNC connector of the HT. I have yet to see a picture of one, however…and that left me with a bit of uncertainty about the construction itself and its inherent durability. So instead if using a battery clip, I decided to use the hose clamp because of availability, ease of use, and the ability to tighten it to the BNC to make sure one won’t loose it in the field. This is also a good idea if you have several different antennas for your rig, so you can temporarily or even permanently attach the Tiger Tail to each antenna.

– Try it out and see the difference for yourself.

Another idea inspired by Ed Harris KE4SKY: For dual-band HTs, try using 2-wire zip cord…of a small gauge, like 18 or even 24. Speaker wire works fine. Cut the wire at the normal 2 meter 1/4 wavelength for the 2 meter side of the counterpoise. Follow the rest of the instructions to finish the single-band Tigertail listed below. Once finished, carefully mark 6.5″ down from the HT antenna connection point and unzip and cut the cord to that length, making a 1/4 wave counterpoise for the 440 band with the shorter of the two wires of the zip cord. Install heat shrink at the split point to keep the zip cord from coming further unzipped.