Comparison between UHF and VHF Radio Frequencies
The mistaken idea that UHF wireless systems are much more advantageous than VHF systems is widespread. However, the facts simply do not support this notion.
There are two major formats for two-way radios. They are Ultra High Frequency (UHF) radio and Very High Frequency (VHF) radio. Both formats are effective ways to communicate with another person. There are a number of important factors to consider. These include where the systems will be used, how they will be used, and for what purpose or application. Let's go over the key components of both frequencies to help you decide which suits your needs better.
VHF signals occupy the low end of the frequency spectrum, from 89.00 MHz to 216.00 MHz. The first wireless transmissions were made from the low frequency band, which has been in constant use ever since. This means that the bandwidth range is abundantly populated.
UHF systems operate in the bandwidth between approximately 450 MHz and 952 MHz. The Federal Communications Commission (FCC) allocated 70 additional channels in 1952 to accommodate the rapid expansion of television in the United States after World War II. UHF bandwidth frequencies are less populated than VHF frequencies.
In simple words, the primary advantage of UHF operation is that there is less chance of interference because of more available frequency spectrum. UHF signals tend to be clearer and are more readily transmitted through metal than VHF signals.
UHF wireless systems always cost more than similar VHF wireless systems. The extra cost of UHF equipment is due to the necessity of using more expensive ultra-high-frequency parts, the greater total number of parts required and the need for more expensive construction techniques.
Battery life for VHF wireless transmitters is almost always better than for similar UHF units. For larger wireless installations, the cost of antennas, cables, antenna splitters and preamplifiers are usually much less for VHF systems and performance is generally better. One disadvantage to VHF equipment can be its size. Since the frequency waves are bigger, an antenna must be bigger.
If the wireless equipment will be used in different cities, VHF systems operating on the special frequencies in the 169-172 MHz range will be a good economical choice (applicable in U.S. and Canada). However, these frequencies, which are sometimes referred to as "traveling frequencies," are very popular, and are not a good choice for situations where large numbers of wireless systems are likely to be present, such as at trade shows and expositions. In such situations, frequency-agile UHF systems will be a better choice.
If you are using your two way radios inside buildings or in a city environment you should always buy UHF since its signal penetrate through walls far better than VHF. If you are only using your radios outdoors (ranching, farming, etc.) then VHF will give you a little more distance.
Source: Free Articles from ArticlesFactory.com
ABOUT THE AUTHOR
This particular article was organized by Devang Kakkad who frequently shares knowledge on the subject areas of technology and communication. He has also written detailed reviews of the best two way radios out there. He recently published his review on Uniden BC72XLT and Midland 75-822 two way radios.