Yaesu UHF transceptores para radioaficionados

How to Get the Lowdown on High Frequency

For all that people use radio in their daily lives, most don't spend a lot of time really thinking about it. They especially don't spend a lot of time thinking about frequency beyond what they see on a 2.4 GHz router or cordless phone.

What is High Frequency?

Any radio transceiver is only effective on a certain range of frequencies; in order to make this more manageable, the spectrum has been divided up into different frequency ranges or bands. One reason for this is that it's a lot easier to make an antenna that's effective over a smaller portion of the spectrum than one that can cover every frequency imaginable. For Ham radio that division breaks the spectrum into three main bands:

• HF:High Frequency is actually the lowest frequency range and longest wavelength of the common bands. Yaesu HF transceivers aim to work with frequencies ranging from 3 to 30 MHz. It's a very well-known Ham frequency and enables the intercontinental communications that helped build the hobby's identity.
• VHF:Very High Frequency radio runs from 30 to 300 MHz and is very common with new Hams. One big advantage of this band is that it's not as heavily used as some others.
• UHF:Ultra High Frequency radio runs from 300 to 3000 MHz and is used by everything from phones to Wi-Fi. Luckily there is plenty of room for amateurs, though the short wavelengths do mean shorter range as well.

How Do You Use a Transceiver?

The difference between a transceiver and receiver is that a transceiver combines it with a transmitter in a single package. Most Yaesu radios are transceivers just because it makes more sense to use one device if you're going to be both transmitting and receiving. This is especially important for mobile operation because don't want to have to lug two devices around. Different HF transceivers operate in different modes. Two of the more common modes are FM and Single Side Band:

• FM:FM is easy to use and a great opening point for Technician class operators. Because it uses channels, it's easy to tune into a conversation and accustom yourself to the world of radio.
• SSB:Single sideband is more complicated, but often more rewarding. It allows for better range and more efficient use of power. This mode is a variation on AM transmission, taking advantage of the fact that in that mode the signal is actually transmitted twice, once on each side of the carrier wave. Single sideband lets you suppress the carrier wave and one of the sidebands, giving you more power for the actual signal. Tuning is a little trickier as it's not channelized, but range is significantly greater.