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.
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.
Approximate build time
- 10 minutes
- Length of wire, the more flexible the better, thin gauge stranded works well
- crimp on spade or ring connector (recommended for SMA style antennas)
- You may use a hose clamp, zip tie, or similar instead of a crimp on connector. (May be required for BNC antennas)
- Wire cutters
- Wire strippers
- Crimping tool
- all these tools can be the same one
- Measuring tape
- Calculator (optional)
Cut the wire
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.
|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 meters = 300/F/4
- length inches = 11785/F/4
where F is the center frequency (the frequency exactly in the middle of your operating band).
Strip the wire
Strip off about 1/4 inch (6mm) from one end of the wire. You may make as many counterpoise/radials as you want. In this photo it is for 2m/70cm dual band.
Install the crimp on connector
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.
Install on radio
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.
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. FRS radios which do not have a replaceable antenna would require you to open the radio to install. You do this at your own risk!
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!