National Bureau of Standards tests of Public Safety high band and amateur 2-meter antennas indicate that a "rubber duck" has -5db, "negative gain" compared to a quarter wave held at face level. In terms of effective radiated power (ERP), this means that a 5w HT with rubber duck, radiates only 1 watt. Placing an HT on your belt results in another -20db attenuation, reducing ERP to 50 milliwatts! UHF results are no better...

This simple helical spring is intended to withstand rough handling, but is not indestructible. Flexible antennas used on fire lines for several weeks showed a 60% failure rate. The California ACS recommends that flexible antennas be replaced annually or more often if they show any apparent kinks, abrasion or other wear to visual inspection.

A simple, inexpensive and effective expedient to improve a "rubber duck" is a counterpoise or "tiger tail. Make this from a quarter-wave piece (19.5" on 2m, 11.5" for 220 and 6.5" for 440) of stranded wire, crimped and soldered to a battery clip. Always reinforce the soldered connection with heat shrink tubing or tape to resist flex. When clamped to the outer collar of the BNC connector on your HT antenna, the counterpose prevents RF from coupling with your body, so your antenna acts like a center-fed dipole instead of an end-fed dummy load! In marginal conditions extending the counterpoise horizontally, pointing your hand to steer the radiation pattern where you need it, produces a dramatically stronger signal than letting it "droop."

Several HT antennas are commonly available which perform much better than the standard helical "rubber duck." Flexible 1/4 wave and telescoping 1/2 wave antennas work very well. A quarter wave provides unity gain when used with a "tiger tail" or counterpoise and held at face level. This simple device represents a 5 db improvement over a typical rubber duck, because most of its effective signal is radiated. If using the HT in a vehicle, use a mobile mag-mount antenna to provide an RF path outside the vehicle. This overcomes the -20db attenuation which otherwise results from operating your HT with a rubber duck antenna inside a metal vehicle. Always carry a male BNC to female UHF adapter so that you can attach your HT to a base or mobile antenna, when one is readily available.

In marginal operating locations a telescoping half-wave is a better performer, because it provides the same unity gain without a ground plane that a 1/4 wave does when used with a ground plane. A 1/2 wave antenna can be pulled up into a tree, dangled out of a window, attached to a window pane with suction cups, or be used bicycle or motorcycle mobile, or in city driving on a window clip mount. Adding a ground plane or counterpoise to a 1/2 wave produces about 2 db of gain. A telescoping half-wave boosts the readable simplex range of a typical 5 watt, 2-meter HT from about a mile with a rubber duck to 3 miles or more, depending upon terrain. Adding a tiger tail improves receive and extends simplex range up to about 5 miles.

Telescoping antennas are more fragile and work best when stationary or in the open, avoiding side impacts or rough handling. Avoid prolonged mobile use of telescoping antennas on mobile window clips at highway speed, because excessive flexing loosens the internal electrical connections. Never collapse a telescoping antenna by whacking it down with the palm of your hand. Gently pull it down with your fingers. If you note any wobbling or looseness, replace the antenna.

Flexible antennas are safer when working in close quarters around people and are more durable when walking through dense vegetation for wildfire suppression or search and rescue operations. They a better choice for dual-banders because most telescoping antennas are single-band. Most common dual-band flexibles approximate a 1/4 wave on 2 meters and a 5/8 wave on 70 cm, are optimized for one band and may resonate poorly on the other. Some antennas do perform better than others, but how efficient a particular antenna is can be determined only by testing.

If you want to buy one emergency HT antenna, without risk or experimentation a telescoping half-wave, flexible dual-band quarter wave; or half-wave, dual-band-mobile magnetic mount, which will work without a ground plane, offer the best "bang for the buck." Whatever HT gain antenna you get should be able to handle 25W so that it can also serve as an emergency mobile antenna or be used with a brick amp. In our group experience the Comet CH-72 and SBB-1 dual-band flexibles, rated for 50w, work well. Adapters enable either to be used on an HT, attached to a mag mount or pulled into a tree with an attached tiger tail and coax leading from a mobile or brick amp.

A mag-mount works best on a car, but an improvised ground plane can almost always be found around the home or office, such as a metal filing cabinet, metal trash can, cookie sheet, rain gutter, refrigerator, window air conditioning unit, balcony railing or any other large metal object. On bikes, motorcycles, Humvees or ambulances with fiberglass caps use a half-wave mobile antenna which doesn't require a ground plane.

Excerpted from: "Getting the Most from Your Hand-Held Transceiver" by C. Edward Harris, KE4SKY, AEC Fairfax ARES (1998)
www.qsl.net/kc4jgc/ht.htm

Don't operate your HT with it hanging on your belt!
Using the radio when it is strapped to your waist reduces your effective radiated power by MORE THAN 10 db!
- That's a 90 % reduction in power!

HOLD YOUR RADIO IN YOUR HAND, and the ANTENNA IN THE CLEAR.

ADVICE ON POWER AMPLIFIERS

An excellent way for HT owners to upgrade their portable ARES/RACES equipment is to purchase a power amp.

An ideal amp should weigh less than 1 pound, be capable of 10 to 15w output when driven by an HT at 1w, or 20 to 40w output when driven by the same HT at 2 to 3w output. It should draw no more than 8 amps of current at its maximum rated output, enabling it to operate safely with Anderson Power Pole connectors or fused cigarette lighter plug.

An FM-only amplifier, without a preamp, will be adequate in most cases.
- A preamp tends to accentuate intermod due to paging transmitters. Unless you equip your portable station with a notch filter and/or cavity bandpass to suppress this intermod, the preamp will serve no useful purpose.

Be wary of bargain "no-name" amps you see at hamfests or in discount catalogs. Some are not aligned for the entire U.S. 2-meter band, many lack thermal protection circuitry for over voltage, overdrive or high VWSR or simply have an inadequate heat sink and will overheat and quit.

Excerpted and updated from: Santa Clara County, California ARES/RACES
Emergency Operations & Your HT (4/21/2002)
www.scc-ares-races.org/emergency_operations_and_ht.htm