Telescoping 5/8 Wave

The telescoping 5/8 wave 2M antenna covers the range of 144-175 and is an alternative to carrying 3 of the rubber duck style. It provides OMNI directional 6 to 9 db gain and is usable in tunable positions. When it has an SMA-M or SMA-F base, it is compatible with the Rat Tail, which results in the mazimum possible gain your are going to get from an antenna used on an HT when you need a ground plane (for ground plane independent antennas look at the 1/2 wave telescoping model). In marginal operating locations a telescoping is much better. A telescoping increases usable simplex range of a typical 5 watt, 2-meter portable from about a mile in average terrain with the stock flexible antenna to 3 miles or more, depending upon terrain, ground clutter, foliage, and any vehicle or building attenuation. However, you can increase this even more if you introduce a ground plane by using the Rattail with it. This antenna we stock is a 'bear'. It provides 6 to 9 db gain and is usable in 2 positions. Fully extended or fully collapsed. It is a true 1/4 wave when collapsed. Modular construction features replaceable telescopic section, tuned coil/spring. This new flex coil matching network provides at band center low SWR as well as a +or - 5 MHz band center.

The advantages to this model are:
1: Steel telescoping antennas yield the maximum amount of gain you can get from any portable antenna to give you the best possible chance to hit a distant repeater or another radio.
2: You can get by if you want to carry just one antenna to suit most of the VHF frequencies you may encounter on a trip by doing some 'gain farming': extending or collapsing sections to improve your gain via trial and error. Guidelines for tuning the collapsing sections is on the right sidebar.

The disadvantages are:
1: not convenient to use. When collapsed they are 10.5", and when expanded they are 48" long. This means you will normally travel with it detached from the radio.
2: When extended on a handheld radio, if held on an angle, it will exert stress on the radio's plastic case where the antenna mounts even though it has a flexible spring on its base. For this reason the antenna should not be carried attached to the radio, always be carried upright when it is attached (any antenna should be used in the perfectly vertical position when transmitting unless your name is Bruce Willis), and always used with the correct base mount form factor (in other words do not use your old telescoping antenna with a BNC base and an SMA adapter).

Order Form Link

Tuning the Omni

Before you head out, look at the list of frequencies you are going to need on your trip and write the channel number and transmit frequency down.
You will collapse sections to tune the antenna to match your transmit frequency so that it falls as close to the middle of these ranges as possible:
• Fully extended: 148-153
• 1 bottom element inserted: 154-160
• 2 bottom elements inserted: 160-166
• 3 bottom elements inserted: 167-176
• 1 top element inserted: 157-163
• 2 top elements inserted: 160-166
• 3 top elements inserted: 167-173
You will receive better if you also tune the antenna, so if you have marginal reception, tune it to the receive frequency using the same guidelines.
These antennas require a ground plane to work best, so hold them perfectly vertical to the ground, and metallic surfaces (such as rock containing iron) are better than porous surfaces. If you cannot hit your target, deploy the Rat Tail and try again.
If you still cannot hit the target, move to higher ground, and fine tune the antenna by trial and error: making small changes to the collapsed and expanded lengths.
Important Note: Specify base connector type required in notes section of order form.
If you are operating in an environment without a ground plane (E.G.: snow, fiberglass or plastic boat), and you are not using a counterpoise adapter, then the 1/2 wave telescoping is a better choice.