Getting on the 220band". St. Lawrence Valley Repeater Council. Archived from the original on 17 April 2009 . Retrieved 27 March 2009. Mexico (222–225MHz) (Band is channelized in some segments, and shared with commercial and government operations, including police.) [44]

In 1938, the FCC gave U.S. amateurs privileges in two VHF bands: 2.5meters (112MHz) and 1.25meters (224MHz). [6] Both bands (as well as 70centimeters) were natural harmonics of the 5-meter band. Amateur privileges in the 2.5-meter band were later moved to 144–148MHz (becoming the modern-day 2-meter band), and the old frequencies were reassigned to aircraft communication during World WarII. At that time, the 1.25-meter band expanded to a 5MHz bandwidth, spanning 220–225MHz. Repeaters: What are they and how to use them" (PDF). American Radio Relay League. Archived (PDF) from the original on 12 May 2008 . Retrieved 27 March 2009. I didn’t have time to go through the full video again to find it (assuming it’s mentioned in this video), but IIRC, the 60mm entrance pupil limit was also a factor in considering the maximum possible diameter of the lens while not obstructing the view of the rangefinder mechanism at MFD. P = 2 tan ⁡ θ ⋅ H = 2 3 ⋅ H ≈ 1.154701 ⋅ H {\displaystyle P=2\tan \theta \cdot H={\frac {2}{\sqrt {3}}}\cdot H\approx 1.154701\cdot H} To take the test, you’ll be asked to cover one eye and read letters on the chart from top to bottom. Your results will be noted as a fraction, with the top number representing the distance. What is Considered Bad Eyesight?The design principles of ISO general-purpose metric screw threads ("M" series threads) are defined in international standard ISO 68-1. [2] Each thread is characterized by its major diameter, D ( D maj in the diagram), and its pitch, P. ISO metric threads consist of a symmetric V-shaped thread. In the plane of the thread axis, the flanks of the V have an angle of 60° to each other. The thread depth is 0.54125 × pitch. The outermost 1⁄ 8 and the innermost 1⁄ 4 of the height H of the V-shape are cut off from the profile. BX's staffing and costs have grown significantly in recent years. Its headcount rose to about 22,300 as of the end of 2022, from 20,000 at end-2017, and now accounts for more than a quarter of Barclays staff, regulatory filings show. Ellis, Todd (6 March 2002). "Why 220MHz?". MRT Magazine. 220MHz: An MRT Special Report. Archived from the original on 18 December 2005 . Retrieved 26 March 2013. Spectrum Management Handbook". Telecommunications Unit Barbados. p.27. Archived from the original (DOC) on 22 December 2015 . Retrieved 10 August 2015.

In the late 1980s, United Parcel Service (UPS) began lobbying the FCC to reallocate part of the 1.25-meter band to the Land Mobile Service. UPS had publicized plans to use the band to develop a narrow-bandwidth wireless voice and data network using a mode called ACSSB (amplitude-companded single sideband). UPS's main argument for the reallocation was that amateur use of the band was very sparse and that the public interest would be better served by reallocating part of the band to a service that would put it to good use. [10]By the 1980s, amateur use of 2-meter and 70-centimeter bands was at an all-time high while activity on 1.25meters remained stagnant. [ citation needed] In an attempt to increase use on the band, many amateurs called for holders of Novice-class licenses (the entry-level class at that time) to be given voice privileges on the band. In 1987, the FCC modified the Novice license to allow voice privileges on portions of the 1.25-meter and 23-centimeter (1.24–1.30GHz) bands. In response, some of the bigger amateur radio equipment manufacturers started producing equipment for 1.25meters. However, it never sold well, and by the early 1990s, most manufacturers had stopped producing equipment for the band. [ citation needed] U.S. reallocation [ edit ] Plan Nacional de Frecuencias"[National Frequency Plan] (PDF) (in Spanish). The National Telecommunications Council (CONATEL). p.62 . Retrieved 8 August 2015.