Articles for Amateur Radio Newsletters aimed at new hams
 written by Gerry Crenshaw, WD4BIS, Rowlett, Texas

 

 

NHP #10: To Dual or Not to Dual: That is the Question

About handitalkies, that is, do you really need that dual band handitalkie. Are they worth their price? Will you use all of their capabilities? Is there enough traffic on 70 Cm to make it worth the effort.

One of the first items purchased by new radio operators is the handitalkie. Believe it or not, the profit margin on these items is very small, hardly worth the effort but the manufactures continue to turn out new smaller more advanced HT's. Many of these HT's now have so many features that when faced with a purchasing decision confusion abounds. Why do the Manufactures even bother cranking out a new, better model every year. The reasoning here lies in customer recognition and loyalty, and putting their name in the hand of as many hams as possible. After making that first buying decision, you will base future buying decisions on how it worked and after- purchase service.

Dual Band handitalkies/mobile come in every combination you can think of 144 and 440, 144 and 220, 440 and 1200 or in any combination you might think of. Why even consider one of these when making that first purchase? Depending on what your plans are the dual band may be your best buy. In many Radio Frequency-congested areas you may need both bands to do the communications you plan. Most emergency and traffic nets will be carried out on one band while casual QSO's and rag chewing will be carried on another. Public service events may use two different bands for different jobs, health, safety and welfare on one band and logistics (delivery of equipment or supplies, trash pick up, etc.) on another or medical traffic such as getting an ambulance to the aid stations or rest stops may be assigned exclusively to a separate band. If your plans include working some sort of Public Service events or working the ‘Thons, a dual band may be worth the expense. Check around first and see what other bands the general ham population is using. 440 mhz seems popular in the Dallas area while 220 Mhz seems to be popular in areas such as New York and Los Angeles.

Another great use of the dual band radio is as a cross-band repeater. A mobile or base station is set up to re-transmit and receive everything from one band to another.

144 Mhz Rx-440 Mhz Tx

440 Mhz Rx-144 Mhz Tx

For example, the 144 Mhz side is left on the repeater frequency and the 440 Mhz side is put on a simplex frequency. This can be very useful in situations where you want to extend the range of a handitalkie. This has been used with considerable success during emergency situations. A couple of things to watch for are picking the frequency to cross band from/to (a seldom-used simplex frequency makes a good choice from the handitalkie to the mobile) and the transmit power level of the mobile. It is very seldom that a radio will have independent control of the power level for both bands. So if you put the 144 Mhz side to high power to reach the repeater you are cross banding to, the 440 Mhz side will also be in high power. This means that one side or the other of the radio will be transmitting in High Power. In the course of several hours this will run down the best Die Hard battery.

The dual band radio is a good for public service work or for the convenience of having two bands in the palm of your hand. They can enhance the operation of any amateur operator in any kind of public service net or event. These make a great addition to any shack but don’t say to good-bye to the kids’ college education money to get one.

73 & GL de WD4BIS

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Copyright 2005 Gerald Crenshaw WD4BIS. All rights are reserved.

Permission in advance is granted to those who use this for non-profit Amateur Radio club newsletters as long as it is used unmodified including this copyright notice and that notice is given to the author via email (wd4bis@arrl.net). In addition, please forward a copy of any newsletter this appears in to: Gerry Crenshaw WD4BIS, c/o GARC, 1027B W. Austin St, Garland, TX, 75040

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