Editing Automatic transmission system (section)

==History==
Traditionally, radio and television stations were required to have a licensed [[operator (profession)|operator]], [[technician]] or [[electrical engineer]] available to tend to a transmitter at all times it was operating or capable of operating. Any condition (such as [[harmonic distortion|distorted]] or [[frequency|off-frequency]] transmission) that could interfere with other broadcast services would require immediate manual intervention to correct the fault or take the transmitter off the air. Facilities also had to be monitored for any fault conditions which could impair the transmitted signal or cause damage to the transmitting equipment.<ref name="HH1996">{{Cite book |last=Hallikainen |first=Harold |chapter=Regulatory History of Operator Licenses and Transmitter Remote Control |chapter-url=https://bh.hallikainen.org/uploads/harold/RegHistory.pdf |title=The NAB Guide to Unattended Station Operation: How to Run Your Transmitter Without an Operator. |date=1996 |publisher=National Association of Broadcasters |isbn=0-89324-247-0 |location=Washington, D.C. |oclc=41334048}}</ref>

Because broadcast transmitters were often at a different location from the broadcast studios, attended operation required an operator to be physically located at the transmitter site. In the 1950s and 1960s, remote control systems were introduced to allow an operator at the studio to power the transmitter on or off.<ref name="HH1996"/> At the same time, an early remote control system, the Automon, was developed by RCA engineers in Montréal that included a relay system that automatically detected if the transmitter was operating outside of its allowed parameters. The Automon could send the studio an alarm if the transmitter was out of tolerance and, if contact to the studio was lost, it could automatically power down the transmitter.<ref>{{Cite web |last1=Potts |first1=Lyman |last2=Norton |first2=Robert |date=2003 |title=Unattended Transmitter Operation — The Automon |url=https://broadcasting-history.com/industry-government/unattended-transmitter-operation-automon |access-date=2022-10-30 |website=History of Canadian Broadcasting |publisher=Canadian Communications Foundation}}</ref> A similar system was developed in 1953 by Paul Schafer in California, using a rotary telephone to raise or lower transmitter parameters remotely.<ref>{{Cite magazine |last=Stine |first=Randy J. |date=2016-06-01 |orig-date=2002-04-10 |title=From the Archives: NAB Honors 'Father of Automation' |url=https://www.radioworld.com/miscellaneous/from-the-archives-nab-honors-father-of-automation |magazine=[[Radio World]]}}</ref>

As [[technology]] improved, transmitters became more reliable, and [[electromechanical]] means of checking and later correcting problems became commonplace. [[Regulation]]s eventually caught up with these advances, to allow of unattended operation via an ATS.<ref name="HH1996"/> During the 1970s, the [[BBC]] made widespread use of automated systems on its [[UHF]] television network to switch from main to standby transmitters in the case of a fault, as well as to alert engineering staff to problems.<ref>{{Cite magazine |date=January 1971 |title=The Unattended Operation of U.H.F. Broadcasting Transmitters |url=https://archive.org/details/bbc-monographs-85/page/n1/mode/2up |magazine=BBC Engineering |issue=85 |pages=2–3 |via=[[Internet Archive]]}}</ref> In 1977, the [[U.S. Federal Communications Commission]] loosened operation rules to allow stations in the United States with ATSes to automatically monitor transmitter operation and allow the ATS to automatically adjust modulation or shutdown the transmitter if operation was out of tolerance,<ref name="HH1996"/><ref>{{Cite web |date=2015-12-13 |title=Unattended Operation of Radio and Television Stations |url=https://www.fcc.gov/media/radio/unattended-operation |access-date=2022-10-30 |website=Federal Communications Commission |language=en}}</ref> although the specific rules have continued to evolve with changes to the [[Emergency Alert System]] and the introduction of [[digital radio]].<ref>{{Cite magazine |last=Stimson |first=Leslie |date=2007-07-04 |title=FCC Looks at Changes to Rules Covering Unintended Operation |url=https://worldradiohistory.com/Archive-All-BC-Engineering/Radio-World-Modern/2007/Radio-World-2007-07-04.pdf |magazine=Radio World |page=3 |via=World Radio History}}</ref>