1.25-meter band explained

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.

Amateur radio

History

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

Pre-Cairo Conference

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.[1]

The Cairo Conference

In 1938 the FCC gave U.S. amateurs privileges in two VHF bands: 2.5 meters (112 MHz) and 1.25 meters (224 MHz).[2] 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.

The VHF/UHF explosion

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 fact that there was an abundance of commercial radio equipment designed for 136–174 MHz and 450–512 MHz that amateurs could easily modify for use on 2 meters and 70 centimeters. 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 1¼ meter operation have been based on conversion of land-mobile base station hardware,[3] often extensively modifying equipment originally designed for other VHF bands.[4]

US Novice licensees get privileges

By the 1980s, amateur use of 2 meters and 70 centimeters was at an all-time high while activity on 1.25 meters remained stagnant. 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 (1.24–1.30 GHz) bands. In response, some of the bigger amateur radio equipment manufacturers started producing equipment for 1.25 meters. However, it never sold well, and by the early 1990s, most manufacturers had stopped producing equipment for the band.

US reallocation

In 1973, the FCC considered Docket Number 19759, which was a proposal to establish a Class E Citizen's band service at 224 MHz. The proposal was opposed by the ARRL and after the explosive growth of 27 MHz Citizen's Band usage, the FCC dropped consideration of the docket in 1977.[5]

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.[6]

In 1988, over the objections of the amateur radio community, the FCC adopted the 220 MHz Allocation Order, which reallocated 220–222 MHz to private and Federal Government land mobile use while leaving 222–225 MHz exclusively for amateur use. The reallocation proceeding took so long, however, that UPS eventually pursued other means of meeting their communications needs. UPS entered into agreements with GTE, McCall, Southwestern Bell, and Pac-Tel to use cellular telephone frequencies to build a wireless data network. With the 220–222 MHz band now left unused, the FCC issued parts of the band to other private commercial interests via a lottery in hopes that it would spark development of super-narrowband technologies, which would help them gain acceptance in the marketplace.

Canadian reallocation

Until January 2006, Canadian amateur radio operators were allowed operate within the entire 220–225 MHz band. Canadian operations within 120 km of the United States border were required to observe a number of restrictions on antenna height and power levels to coordinate use with non-amateur services in the United States.[7]

In 2005 Industry Canada decided to reallocate 220–222 MHz to land mobile users, similar to the US, but unlike in the US, a provision was included to allow the amateur service, in exceptional circumstances, to use the band in disaster relief efforts on a secondary basis. In addition, the band 219 to 220 MHz was allocated to the amateur service on a secondary basis. Both of these re-allocations went into effect January 2006.

The band today

Canadian band plan

License class! style="width: 50px;"
219–220220–222222.00–222.05222.05–222.10222.10–222.275222.275–222.300222.31–223.370223.39–223.490223.49–223.590223.59–223.890223.91–225
Basic(+), Advanced
style="width: 25px; background-color: purple"
= Available on a secondary basis to other users.
= Available only to assist with disaster relief efforts.
= Reserved for EME (moon bounce)
= Continuous wave (CW), 222.1 calling freq.
= SSB, 222.2 calling freq.
= propagation beacons
= FM Repeaters (input −1.6 MHz)
= High speed data
= FM simplex

Scope of operation in North America

Today, the 1.25 meter band is used by many amateurs who have an interest in the VHF spectrum.

There are pockets of widespread use across the United States, mainly in New England and western states such as California and Arizona with more sporadic activity elsewhere. The number of repeaters on the 1.25 meter band has grown over the years to approximately 1,500 nationwide as of 2004.[8]

The attention that 1.25 meters received in the late 1980s and early 1990s due to the reallocation of the bottom 2 MHz sparked a renewed interest in the amateur community. Many amateurs feared that if activity on 1.25 meters remained sparse, it would only be a matter of time until broadcast regulators reallocated the remaining 3 MHz to another service.[9] Today, there are new handheld and mobile equipment being produced by amateur radio manufacturers. It is estimated that more amateurs have 1.25 meter equipment now than at any point in the past.[10]

Auxiliary stations

An auxiliary station, most often used for repeater control or link purposes or to remotely control another station, is limited in the United States to operation on frequencies above 144.5 MHz[11] excluding 144.0–144.5 MHz, 145.8–146.0 MHz, 219–220 MHz, 222.00–222.15 MHz, 431–433 MHz, and 435–438 MHz. Operation of such control links in the crowded 2-metre band is problematic[12] and on many frequencies in that band expressly prohibited, leaving 1¼-metre band frequencies (222.15 – 225 MHz) as the lowest suitable for remote control of repeaters and unattended stations.[13]

List of transceivers

A full list of new and used 220 MHz tranceivers is available. http://members.shaw.ca/francislyster/220/index.html

Since the band is allocated mostly in ITU Region 2 (Somalia, in Region 1, being the only exception thus far), the major equipment manufacturers (Kenwood, Yaesu, and Icom) do not often offer transceiver models that cover the frequency range. (see Novice licensees get privileges). This exacerbates the lack of usage of the 1.25 meter band, though manufacturers argue that what equipment they have produced hasn't sold well compared to other products.

In recent years, Kenwood and Yaesu have both included the 1.25 meter band in some of their multi-band handheld transceivers. The Kenwood TH-F6A, the Yaesu VX-6R, VX-7R & VX-8R (USA and Canada version) include coverage of the 1.25 meter band in addition to the more popular 2 meter and 70 centimeter bands. Wouxun now has the KG-UVD1P in a 2 meter/220 model, legal for USA use. However, in the 1980s, ICOM offered the IC-37A which was a 220 MHz, 25 watt FM transceiver and can still be obtained as used equipment from various sources. Even though this radio is 30+ years old, it is highly collectable and many are still in service to this day.

Aside from handheld transceivers, the only two 1.25 meter transceivers widely available today are offered by Alinco (the DR-235T) http://www.alinco.com/Products/DR-235/ and Jetstream (the JT220M) http://www.jetstream-usa.com/jt220m.shtml, both Japanese manufacturers.

The Chinese company Wouxun is marketing a 2M-220Mhz dualband HT, the KG-UVD1P. http://www.wouxun.com/Two-Way-Radio/KG-UVD1P.htm These transceivers have received FCC Approval in the USA; but are awaiting Industry Canada approval in Canada. They can be purchased from a USA seller, with the appropriate FCC ID label from: http://www.wouxun.us. With low-cost radios available now, there are hopes to revive this band.

Elecraft offers an all mode (CW, FM, SSB) transverter for the 220–225 MHz band[14] compatible with their popular K2 and K3 transceivers.

Countries with known allocations

ITU Region 1

ITU Region 2

Notes and References

  1. DeSoto. Clinton B. 200 Meters and Down: The Story of Amateur Radio, 2001 edition. Newington, Conn.: The Amateur Radio Relay League. p. 129.
  2. Francis Colt de Wolf. The Cairo Telecommunication Conferences. The American Journal of International Law, 32;3(July 1938):562–568.
  3. http://www.jonadams.com/pages/amateur_radio/ge_mastr_2_220mhz_mods.htm GE Mastr II Modifications for 220MHz
  4. http://www.repeater-builder.com/rbtip/222menu.html 222 MHz Motorola Micor Modifications
  5. http://jplarc.ampr.org/calling/1977/nov/nov77.html JPL amateur radio club newsletter, retrieved 2010 Feb 09
  6. http://220.mrtmag.com/ar/radio_why_mhz/index.htm Why 220MHz?
  7. http://www.rac.ca/en/rac/services/bandplans/220/agr.php Radio Amateurs of Canada interpretation of the 220 MHz operating agreement, retrieved 2010 March 14
  8. http://www.arrl.org/tis/info/pdf/repeater1.pdf Repeaters – what are they and how to use them
  9. http://www.rac.ca/opsinfo/220mhz.htm 220 MHz (125 cm) info
  10. http://www.slvrc.org/220band.htm Getting on the 220 Band
  11. http://www.arrl.org/FandES/field/regulations/news/part97/c.html#201 FCC regulations, part 97, subpart C
  12. http://www.fcc.gov/Bureaus/Wireless/Orders/2000/da001662.txt Federal Communications Commission
  13. http://www.mrc.gen.mn.us/010902/rptaux.htm What is the difference between a repeater and an auxiliary station?
  14. http://www.elecraft.com/XV/XV.htm Elecraft XV Series Transverters
  15. Aruba application for a visitor's license. http://www.qsl.net/aarc/P4A.PDF accessed 1 November 2008.
  16. French Amateur Radio frequency allocations http://accueil.ref-union.org/jo_031008.pdf accessed 1 November 2008.
  17. Web site: Mexico Amateur Radio frequency bands and channel allocations. PDF. 15 December 1994. 1 November 2008. http://www.webcitation.org/5keWF8Qil. 19 October 2009. yes.
  18. Web site: Trinidad and Tobago Frequency Allocation Table (9 kHz to 1000 GHz). The Telecommunications Authority of Trinidad and Tobago. 27. PDF. 16 October 2009. 15 November 2009.