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Getting the Most from Your HT!

Charles E. Harris (KE4SKY) on September 27, 2001
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Getting the Most from Your Hand-Held Transceiver

İ1998-2001 Virginia RACES, Inc. Nonprofit reproduction is permitted with source attribution

Ed Harris, KE4SKY, Virginia State RACES Training Officer

If repeaters are unavailable after a disaster and you are limited to simplex operation, a portable transceiver with its original flexible antenna is inadequate for emergency communications.

I started with a "handy-talkie" or "HT" when I first got my ham license. Today, as Virginia ARES / RACES training officer I recommend that new operators buy 2-meter mobile transceivers. They cost no more than a portable. Today's equipment is very compact, rugged and reliable. For portable operation, carry the mobile transceiver in a briefcase with a 17ah-gel cell battery and telescoping 1/2 wave or magnetic-mount mobile antenna. Include 25 feet or more of coax to get the antenna up high, away from people. This arrangement may not work for everyone. Therefore, if all you have is a portable transceiver, the following will help you to make the most of it!

An "HT" makes perfectly good sense for:

· Anyone who doesn't drive;

· Commuters who use public transportation;

· Controlling a mobile radio as a cross-band repeater

· As a spare, a backup or loaner.

The National Institute of Science and Technology tested Public Safety "high-band" VHF and amateur 2-meter antennas. Flexible antennas commonly used on portable transceivers have negative gain compared to a quarter wave whip held at face level.This means that 5-watt portable VHF with stock antenna has an effective radiated power of only 1-watt. Placing the portable on your belt produces -20db of attenuation, reducing EIRP to 50 milliwatts! UHF results are no better...

"Rubber ducky" antennas are rubber covered helical springs, which are intended to withstand some rough handling, but they are not indestructible. Flexible antennas used on California fire lines for several weeks showed a 60% failure rate. Flexible antennas should be replaced annually or as soon as they show ANY apparent kinks, cracks, abrasion or other wear to visual inspection.

An effective expedient to improve a flexible antenna is to attach a counterpoise (19.5" long for the 2-meter band, or 6.5" for the 70 cm band) of stranded wire, crimped and soldered to a battery clip or ring terminal which will fit over the antenna connector. Reinforce the soldered connection with heat shrink to resist flex. When attached to the outer collar of the BNC connector or the antenna shield, the counterpoise prevents transmitted RF from coupling with your body. This enables it to perform like a center-fed dipole, instead of an "end-fed dummy load!" The main lobe of the radiation pattern can be "aimed" by, grasping and pointing the end of the counterpoise in the direction where you need a stronger signal.

Some after-market and home-made antennas perform much better than the standard helical "rubber duck." A J-pole antenna constructed of 300-ohm twin-lead rolls up and fits into your pocket. When thrown up in a tree, it increases both height and gain. Full-sized, flexible 1/4 wave and telescoping 2-wave antennas work very well.

A quarter wave provides unity gain when used with a counterpoise and held at face level. This represents a 5 dB improvement over a stock flexible antenna, because most of the effective signal is radiated. If operating from a vehicle, connect your portable to a magnetic mount mobile antenna to provide a clear RF path outside the vehicle. This overcomes the substantial attenuation, which results from operating a portable unit from inside a metal vehicle. Always carry suitable adapters so that you can connect your portable transceiver to an outside base or mobile antenna, when one is readily available.

In marginal operating locations a telescoping, half-wave is much better, because it provides the same unity gain without a ground plane that a 1/4 wave antenna does when used with a ground plane. A 2-wave antenna can be pulled up into a tree, dangled out 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. A telescoping half-wave increases useable simplex range of a typical 5 watt, 2-meter portable from about a mile with the stock flexible antenna to 3 miles or more, depending upon terrain. Adding a counterpoise to an efficient antenna enables a portable unit to keep in reliable contact within 5 miles of an EOC or base station equipped with an efficient antenna elevated on a tower.

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 window clip mounts at highway speed, because excessive flexing loosens their 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 better for dual-band transceivers because telescoping antennas are usually mono-band. Dual-band flexible antennas 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. How efficient a particular antenna is can be determined only by testing. A telescoping half-wave, or half-wave, dual-band-mobile antenna with magnetic mount, will work well either with or without a ground plane, and offer the best bang for the buck.

Any emergency antenna for your portable transceiver is rated to safely handle up to 25 watts of RF output. This enables it to be used as an expedient antenna for a mobile radio in portable operation, or to permit use of an external "brick" amplifier with the portable transceiver.

A magnetic 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 boats, motorcycles, fiberglass truck caps or wooden balcony railings use a half-wave antenna, which does not require a ground plane.

BATTERY POWER BASICS

A common error of new ARES / RACES operators is failure to plan to carry enough battery power. Always carry at least one spare charged NiCd pack and AA battery case, which enables you to keep operating when the power goes off, if you can't recharge your NiCd pack.

Cycle and recharge dry NiCd packs monthly. Write the recharge date on a strip of tape on each pack. In cold weather keep NiCd packs warm by keeping them in an inside coat pocket and not exposed on your belt.

An adapter cord to power your transceiver from an auto cigarette lighter plug or a gel cell battery is needed for extended operation. Cigarette lighter cords are often unreliable because auto sockets aren't the best conductors, due to contamination and size variations, which cause the plug to vibrate loose. As an alternate power source, you should still have one, because they are ubiquitous and in a pitch, much better than nothing!

Portable power packs such as Quantum are excellent, but expensive. We encourage our operators to make their own using 12-volt gel cell batteries obtained from local hospitals. Sealed lead-acid (SLA) batteries are used to power emergency lighting, alarm systems, medical instruments and computer backup power supplies. They are replaced on a fixed schedule, usually before they are worn out. Because SLA batteries require disposal as hazardous waste unless recycled or reused, a hospital donation to your CERT or ARES / RACES group reduces their disposal cost. Contact your local hospital and explain how SLA batteries they discard can support auxiliary emergency communications.

Donated SLA batteries must be inspected, recharged and load-tested. Any 12V batteries with an open circuit voltage (Voc ) of 12.8V or more are tested immediately and distributed for reissue, if OK. Batteries with Voc <12.8V are connected in parallel across a regulated 13.8V power supply. Those which are not accepting charge after 4 hours are discarded. Total charge time and current should not exceed 140% of battery capacity. Gel cells should never be recharged at over 14V due to gassing.

Reject batteries if their internal resistance exceeds an ohm, as determined by voltage drop divided by the current load in amps. Good batteries suitable for re-issue should not drop below 11.7V under a test load approximating AC,@ their amp-hour capacity, for 30 seconds or AC/5" for one minute.

A simple test load for small gel cells up to 20ah is a 50w, 12V-marine/RV bulb or automotive droplight. This equals about 3.8A, approximating a mobile radio on low power 5w transmit or a portable 2-meter hand held, plus a laptop PC and packet TNC. Using two bulbs and 'Y' adapter simulates mobile or brick amp at 25w RF output. This is a good test load for batteries to 30amp-hours. In a good battery, voltage drop stabilizes quickly, does not fall below 11.5V under load, and recovers quickly when the test load is removed.

STANDARD POWER CORD CONNECTORS

Auxiliary power cords should follow the configuration shown in the ARRL ARES Resource Manual. Use twin lead, red-black AWG14 or AWG16 zip cord with Molex Series 1545, 2-pin polarized connectors and .093 pins. The female pins are assembled into the male plug, which is attached to the power source, and the male pins into the female receptacle, which is attached to the rig.

The plug, receptacle and pin set is rated for 8A continuous duty and costs $0.99 from Radio Shack, Part No. 274-222. Wiring is simple. The end of the two-conductor Molex plug in cross section resembles a little 2-story house with peaked roof. Remember proper polarity by the word associations red roof and black basement, or pointy positive and flat black. Crimp wires before soldering to ensure a strong connection. After inserting the pins into the plug and receptacle, check fit of the assembled fitting. Reinforce the wires behind the plug and receptacle with heat shrink or tape. On the battery ends attach crimp type female tab terminals to fit the male tabs on the battery.

It is recommended that you rig two sets of cords directly to your car battery to power your portable or mobile radio, and laptop computer, if you will send data via packet radio to your EOC. Splice type fuse holders onto both leads, as close to the battery as possible.

If all you have is a portable transceiver, the above information will help to ensure that you can provide an adequate signal for reliable emergency communications. Doing so is vitally necessary to enable your volunteer disaster unit to complete its mission efficiently and safely. More training materials for amateur radio operators to learn essential core skills in emergency communications are featured on the Virginia ARES / RACES Training page located at: http://va-ares.org/Training/training.html

Member Comments:
This article has expired. No more comments may be added.
 
Getting the Most from Your HT!  
by W5RDF on September 27, 2001 Mail this to a friend!
In these times, we need to be prepared for any contegency. The information on HT's is very timely. We need to carry a personal "kit" with us whenever we leave home. In addition to an HT with spare batteries and a rollup J pole. Other items include a small rugged 2 AA cell flashlight. In addition equip yourself with a cellular telephone with a spare battery, plus a disposible zinc air battery. The zinc air batteries are available at a lot of retail outlets for the specific cell phone you have. Now all of us don't subscribe to cellular service, the FCC has mandated that any cellular phone, regardless can dial 911. So dig up an old cell phone and throw that in you kit bag. Don't pick a phone that is specific to certain operaters, i.e. Sprint, Nextel, etc. Stick with an old 800 MHz phone that will operate on the orginal 800 MHz cell networks. Finally, be safe.
 
Getting the Most from Your HT!  
by KE4OAR on September 27, 2001 Mail this to a friend!
Good information.

In east Tennessee, we are moving away from the Molex connector in favor of the 30 amp Anderson PowerPole.

The main advantages to the PowerPole are you only need one set of connectors for either side giving great flexibility without the need for adapters and you only need to inventory one connector.

The connectors can be assembled in a multi-connector block to allow a single power source to supply multiple items.

They are color coded so that, if you follow the convention, there is no doubt which is the correct polarity.

They do have two minor disadvantages. First you have to make sure you follow the correct convention in assembling the connector so as to be compatible with others.

Second, they are not available at the local corner Radio Shack. But, when purchased in large quantities, they get down to under a $1 a connector. I always keep a bunch on hand for new equipment and emergencies.

 
RE: Getting the Most from Your HT!  
by K7LU on September 27, 2001 Mail this to a friend!
KE4OAR, more info please. Where is more information about these connectors available?
Who do you order them from?
 
RE: Getting the Most from Your HT!  
by AB0RE on September 27, 2001 Mail this to a friend!
The PowerPoles can be ordered from www.powerwerx.com. I personally haven't used them but have heard good things about them. I'd appreciate any feedback anybody else could offer as well.

Thanks for the article - great food for thought. 73.
 
Getting the Most from Your HT!  
by N6AJR on September 28, 2001 Mail this to a friend!
Great article... thanks.. Tom N6AJR
 
Getting the Most from Your HT!  
by N1KFC on September 28, 2001 Mail this to a friend!
The molex connectors are indeed rather dated. The ARRL's Emergency Communications course now references the Anderson powerpole. As for the www.powerwerx.com site, I have been ordering from them for several years and have had nothing but good experiences. Highly recommended.

Good article! Perhaps you might like to expand it a bit to cover Li ion batteries for example. More of this type of article would be welcome on eHam.

73,
Mark
N1KFC
 
Getting the Most from Your HT!  
by AF5II on September 28, 2001 Mail this to a friend!
someone should market a zinc air battery for HT's. Those would be great when your in a bind
 
Getting the Most from Your HT!  
by K3UOD on September 29, 2001 Mail this to a friend!
More good info on this subject on the "Station Building " forum.

See threads on "12V Distribution Idea" and "How to set up a deep cycle battery..."
 
Getting the Most from Your HT!  
by AH6RH on September 29, 2001 Mail this to a friend!
I agree with the majority of the points. Some additional items.

1) Absolutely bravo on the use of mobile radios and not handhelds are the primary radios. Handhelds can't stand up to the duty cycles (50% or more) that's required in the field. Running 5 watts on the modern micro-mini handhelds will roast your hand in a minute of operation. It's more equipment, but run 5 watts off a mobile radio, and you'll never worry about overheating the rig.

2) If you have an early response to a difficult situation, you'll need to organize the response team as a number of individuals with handhelds relaying through a person in a mobile. This is until others can come onsite with portable stations comprised of 2m mobile equipment.

3) Let your antenna do all the work. My preferred antenna is the Diamond NB73BNMO on a NMO mag mount. It's a end-fed half wave at 2m, and co-phased 5/8 wave on 440. Requires no ground plane, is light and portable, can be used as a standalone antenna on a non-conducting surface or as a magmount on a vehicle.

4) I fully support the Anderson Powerpoles as the preferred connectors. Advocated in California, Pat, W0IPL and I tested these connectors prior to including them in the ARRL Emergency Communications Level I Course. It's the only inexpensive, durable, reliable connectors I know of that can handle up to 30 amps, that I can snap together in pitch black darkness, a fraction of a second, and not worry about mixing up the polarization or shorting out the connector based on exposed terminals. The molexes has a tendency to fuse together when high current is run through them.
If you want to be fully prepared, make several Powerpole-to-bare wire pigtails. You can always attach another type of connector to it and power the rest of your system. Note that the Powerpoles are independent of whether it's the end for the rig or the battery -- so you can use these pigtails to power your equipment, or your "guest's" equipment. That's something the Molex cannot do.

5) I highly encourage amateurs to be educated in emergency communications equipment, methodologies, and operations. They should be registered with ARES, RACES, SKYWARN, SATERN and similar organizations ahead of time and get the necessary IDs and clearances before it's needed.

6) Additional info can be found at:

http://home1.gte.net/rhashiro/am-ecomm.htm

Ron Hashiro, AH6RH
 
Getting the Most from Your HT!  
by W4CNG on September 30, 2001 Mail this to a friend!
The Anderson Power-Pole connectors are the way to go in this day and time. Two years ago I supported the molex (RS) connector. After working with the Power-Pole connector, I am recommending that all of our members in North Fulton GA move to that connector of choice. I have purchased a good supply of them, as they are not available around the corner, that was my primary objection two years ago. Useful items must be available to everyone easily. Easily is now a large stock for all. I have built 1-2 and 1-3 multiplier connectors for my ready bag, which now includes a 12A/12V gel cell.

Charles' web site in VA is very informative with lots of good info for all to not have to re-invent the wheel.

73 Steve W4CNG Training Director North Fulton A.R.E.S
www.fultonarea.org
 
RE: Getting the Most from Your HT!  
by KA0AZS on October 1, 2001 Mail this to a friend!
The only place I'd differ with Ron on antenna (I use Diamond versions of the type of antenna he described for Bike and Shelter operations) would be to go with the PL-259/SO-239 versions of the antenna. I find it much easier to interface the antenna with coax runs if I'm setting up a field expedient antenna site than with NMO. My spare mag mounts are of the same type, and I can easily plug extensions of coax into them to extend the run if necessary.

I also have SO239/NMO and NMO/SO239 adaptors I picked up at a hamfest to make sure I can use my antennas with the widest possible range of set ups I might run into.

Good Comments all

73

Randy KAĜAZS
 
Getting the Most from Your HT!  
by N0TRK on October 2, 2001 Mail this to a friend!
Power poles are EXCELLENT. I have a variety of power pole jumpers to vaious types of connectors including "bare wire". I keep these in my emergency pack and take them with me on any community service net. I recommend these 110%.

Other things to have an extra of is a head set with microphone. I don't much care for speaker mikes, but the head sets free your hands to hear and keep the noise down. It also saves on your battery because you don't have the volume cranked. Having a spare helps if you happen to break a wire, or if someone doesn't have one.

This information is excellent!

Thanks

Mary Joseph
Deputy EC, Midlands ARES of Douglas Co. Nebraska
 
Getting the Most from Your HT!  
by AB2MH on October 2, 2001 Mail this to a friend!
For the WTC disaster relief efforts with NYC ARES and Red Cross, a handheld just didnt cut it. So I carried my Icom 746 and some wire in my bag, and a tuner just in case, and a 5/8 mag mount. You never know, a power station could be knocked out and there goes ALL of our repeaters, and you would need HF or VHF simplex. One of the other hams told me "are you going to do DXing down there?"

I said, "no, repeaters arent indestructible and we lost quite a few repeaters that were on top the twin towers". I carried my VX5, so that when I was moving I would be in touch, but a handheld simply wouldnt work from some of the sites. Too many fried eggs and chopping on the repeater. Also too many dead batteries. You need a mobile rig and some real juice. Handhelds just dont cut it anymore.

73, Ryan AB2MH
NYC ARES AEC Manhattan
 
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