Nuts and Volts - September 2015

September 2015 17

THE LATEST IN NETWORKING AND WIRELESS TECHNOLOGIES

many objects but are greatly attenuated. Furthermore, physics state that higher frequencies travel over shorter distances for any given power and receiver sensitivity. What all this boils down to is a very short potential range. For a handheld, the range is probably only a few miles at best unless you stand on a tall building or put up an external antenna -- which I cannot do.

Anyway, those facts should have dawned on me when I started this process. I live in a small town outside of Austin, TX. Most of the ham activity is within the city, so my potential for making contacts is minimal. Nevertheless, I tried.

Checking Out the Two-Meter Band

The two-meter band has more activity and longer range potential, so I focused my efforts here. One benefit of this band is the availability of repeaters to extend the range. A repeater is a station that is usually located at a high point so it can cover a wide area. The repeater receives a signal from a low power handheld or mobile unit, then retransmits it on a different frequency at a higher power level. A cell phone tower site does the same thing.

For example, in the two-meter band, a handheld will transmit on 146.34 MHz -- the receive frequency of the repeater. The repeater retransmits on 146.94 MHz. The 0.6 MHz spacing allows the repeater to utilize the same antenna for transmit and receive using a duplexer -- a filter unit that keeps the simultaneous signals separate. The repeater produces a huge increase in the coverage range of portable units.

I checked the American Radio Relay League (ARRL) repeater directory to locate potential nearby repeaters. I identified about a dozen potential candidates. Using the scan function on the HT, I was able to pinpoint some I could hear.

Unfortunately, I was too far away to make contact.

Another factor is that most repeaters use a continuous tone coded squelch system (CTCSS) to access a repeater. This is the use of a unique audio tone that a transmitter must momentarily transmit before the repeater will respond. There are 42 possible tones from 67 Hz to 254.1

Hz. You need to know that tone to use the repeater. Most HTs can be set up to automatically transmit the tone once you know it. The ARRL repeater directory gives these tones as well as the operating frequencies.

The only way that I was able to make any contacts was to drive into Austin at some elevated point where I could access several repeaters. I made many contacts to confirm the HT’s operation, which was satisfactory. Unfortunately, most repeater users do not seem to engage in casual rag chewing, as in using other bands and modes. Many repeaters belong to clubs so the users are generally familiar with one another.

Back in the Saddle

So, I am back on the air. Sadly, it’s been a somewhat disappointing experience. The combination of an agonizingly hard-to-use transceiver and the short range really limits what you can do. Unless you use repeaters or put up a high outside antenna, potential contacts will be few and far between. HTs are probably great for emergencies, but are not so enjoyable as a ham experience. (Just my opinion, of course.)

My next attempt will be to get back on the high frequency (HF) ham bands using CW. That will occur when I can figure out what to do about a stealth antenna. I’ll let you know how that goes in a future column. NV

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