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Many hand held radio antennas are only half of an antenna. They have the whip part, but nothing for a ground plane. Since hand held radios are small devices they usually do not have a good counterpoise to act as a ground plane.  This causes the radios to under perform.  A tiger tail can correct this problem.

This concept can be applied to mobile/base antennas increasing their performance, although most mobile antennas use the vehicle as the counterpoise, the missing half of the antenna, and while on a vehicle you may not see any benefit to using it on those antennas.  This will almost always be required if you mount a mobile antenna on a tripod for portable use or on a balcony or other home structure.  If you attach it to a mobile/base antenna you would do this at the base of the antenna and not at the feedpoint from the radio.

You will need about 10 minutes to make this tiger tail, and it only takes the most basic skills. It is an easy project suitable for people of all ages.

This simple to make antenna supplement provides the “other half” of the antenna and allows more radio signal to radiate from your antenna, increasing rage. It will work on ham radios as well as CBs, GMRS, or anything that you can attach it to. This can also be the difference between getting your signal to the receiver and not.

It may not be legal to attach this to all radios. Radios which are limited by an ERP (effective radiated power) under the regulatory agency in your region (FCC in the US), may exceed their maximum allowed transmit power. In general if the antenna is easily detachable this will be legal to attach.

The common name of this is a tiger tail. It is just a counterpoise or radial. You can attach this when needed, or keep it on all the time, whatever is best for your situation. If you hold it so the wire points at the receiver for slightly increased range over what you get with it just hanging down.

This helps the radio signal have something to “push off” from, which causes more radiation off your antenna, resulting in a higher signal output.

This will not help receive much if at all, and in some situations can increase the noise floor by sending noise into the ground. Fortunately they disconnect easily so you can verify if that is the case for your radio, in the environment you are operating it at the time.

A tiger tail is the common name, a google search reveals many plans for such a device. It is just a counterpoise or radial, when attached to your handheld transceiver will yield much greater performance. You can attach this when needed, or keep it on all the time, whatever is best for your situation. If you hold it so the wire points at the receiver for slightly increased range over what you get with it just hanging down.

This helps the radio signal have something to “push off” from, which causes more radiation off your antenna, resulting in a higher signal output. Please note that this is not suitable for all radios, some radios use an antenna type that requires the imbalance that is present in a simple vertical, these however are not the majority of transmitters.

Parts list

length of wire, the more flexible the better.  Thin gauge stranded works well.
Crimp on spade or terminal connectors
You may use a hose clamp instead of Crimp on spade connectors, and if you have a BNC antenna connector you may be required to use a small hose clamp.

Tool list

Wire cutters
Wire strippers
Crimping tool (most of these work as a wire stripper and cutter too)
tape measure
Calculator (optional)

Construction

You will want to get a length of wire that is 1/4 wavelength of the center frequency for the band you want to operate on.

Use one wire for each band you plan on operating on.

Band	Frequency Range	Center Freq	Wire length
2m US	144-148MHz	146MHz	20.18 inches (51.26cm)
2m UK	144-146MHz	145MHz	20.32 inches (51.61cm)
70cm US	420-450MHz	440MHz*	6.7 inches (17cm)
CB US	26.965-27.405MHz	27.185MHz	108.38 inches (275.28cm)

^* 420-430 is not valid above the “A” line, and its mostly inter-repeater links or data

You may use the following formula to make the wire for any frequency.

length centimeters = 30000/F/4

length inches = 11785/F/4

where F is the center frequency (the frequency exactly in the middle of your operating band).

Strip off about 1/4 inch (6mm) from one end of the wire. In this photo I am making one for 2m/70cm.

Attach the crimp on connector, if desired and if they are the heat shrink type (most are), apply heat from a lighter or other source to shrink the protective covering.  This will also help add some stress relief to the connection preventing it from coming undone if it gets snagged on something.

Loosen your antenna and slide this in so it touches the ground, then tighten your antenna.

If you use a hose clamp you will connect it to any exposed metal on the base of the antenna, in the photo below, it would be the golden part. You need good mechanical (and thus electrical) contact with the ground connection, so the tighter the better.  Be careful not to crush your antenna connector though!

The ground is almost always the outer part, and most antennas have some exposed metal at their base. If need be you can open the radio and connect it solidly to the outer part of the antenna connector. You do this at your own risk!  It also may not be legal to attach this to radios where the antenna is not replaceable, be sure to verify the laws before doing that.

Some antennas such as the Yaesu VX7 and VX8 submersible radios have a bit of extra rubber at the base, this is the stock antenna (which is of poor quality to begin with). In order to use that antenna you will likely have to cut a small bit of the rubber away so that everything fits properly (this is not recommended, you will lose some of the submersible protection by doing this, although the SMA jack is generally well protected anyway).

That is all there is to it!