*** Welcome to piglix ***

1.25-meter band


The 1.25 meter, 220 MHz or 222 MHz band is a portion of the VHF radio spectrum internationally allocated for amateur radio use on a primary basis in ITU Region 2, and it comprises frequencies from 220 MHz to 225 MHz. In the United States and Canada, the band is available on a primary basis from 222 to 225 MHz, with the addition of 219 to 220 MHz on a limited, secondary basis. It is not available for use in ITU Region 1 (except in Somalia) or ITU Region 3. The license privileges of amateur radio operators include the use of frequencies within this band, which is primarily used for local communications.

The 1.25-meter band has a very long and colorful history dating back to before World War II.

Some experimental amateur use in the U.S. was known to occur on the "1¼-meter band" as early as 1933, with reliable communications achieved in fall of 1934.

In 1938 the FCC gave U.S. amateurs privileges in two VHF bands: 2.5 meters (112 MHz) and 1.25 meters (224 MHz). Both bands (as well as 70 centimeters) were natural harmonics of the 5-meter band. Amateur privileges in the 2.5-meter band were later reallocated to 144–148 MHz (becoming the modern-day 2-meter band), and the old frequencies were reassigned to aircraft communication during World War II. At this time, the 1.25-meter band expanded to a 5 MHz bandwidth, spanning 220–225 MHz.

Amateur use of VHF and UHF allocations exploded in the late 1960s and early 1970s as repeaters started going on the air. Repeater use sparked a huge interest in the 2-meter and 70-centimeter (420–450 MHz) bands, however, this interest never fully found its way into the 1.25-meter band. Many amateurs attribute this to the abundance of commercial radio equipment designed for 136–174 MHz and 450–512 MHz that amateurs could easily modify for use on the 2-meter and 70-centimeter bands. There were no commercial frequency allocations near the 1.25-meter band, and little commercial radio equipment was available. This meant that amateurs who wanted to experiment with the 1.25-meter band had to build their own equipment or purchase one of the few radios available from specialized amateur radio equipment manufacturers. Many of the repeaters which have been constructed for 1.25-meter operation have been based on converted land-mobile base station hardware, often extensively modifying equipment originally designed for other VHF bands.


...
Wikipedia

...