Subj : Todays New Gear Tip
To   : All
From : Daryl Stout
Date : Thu Oct 19 2017 12:08 am

Frequencies and Modes 

Commercially available HF transceivers cover all of the amateur bands
described in the introduction to this section. Some add the 6 meter band
from 50 to 54 MHz and even VHF/UHF bands from 2 meters to 23 cm (1.2 GHz).
These radios are "all-mode", using AM, SSB, CW, FM, and digital modes.
You can use these radios for everything from contacts on your local
repeater to long-distance contacts on the HF bands where SSB and CW are
the most popular modes. The ARRL Operating Manual discusses the
characteristics of the different HF and VHF/UHF bands. 

The longer wavelength HF bands (160 to 30 meters) are generally used for
local and regional contacts through the day, but support long-distance
(DX) contacts at night. Shorter wavelength bands (20 to 10 meters) "open"
and provide long-distance contacts through the day, but "close" at night
when the signals are no longer reflected back to Earth by the ionosphere. 

The VHF and UHF bands support line-of-sight regional contacts and
long-distance contacts via several interesting means of propagation.
This is called weak-signal operating and is conducted on 50, 144, and
432 MHz mostly using SSB and CW because those modes work better at
low signal-to-noise ratios, while FM requires stronger signals to be
effective. 

While able to transmit only in the ham bands, HF radios typically include
general coverage receivers that can tune from a few hundred kHz to 30 MHz.
(Medium wave (MW) stations use frequencies from 300 kHz to 3 MHz and long
wave (LW) below 300 kHz.) 

Ham band only receivers don't offer this coverage. Wideband receive
coverage extends above 30 MHz into the VHF and UHF range. The Wikipedia
entry on "shortwave" (en.wikipedia.org/wiki/Shortwave) will give you an
idea of what you can listen to. The VHF/UHF section on frequency coverage
will help you decide if wideband receive is useful for you. 



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