WGN-TV

==Technical information==
===Subchannels===
The station's signal is [[Multiplex (TV)|multiplexed]]:
{| class="wikitable"
|+Subchannels of WGN-TV<ref name="rei">{{cite web |title=RabbitEars TV Query for WGN-TV |url=http://www.rabbitears.info/market.php?request=station_search&callsign=WGN#station |access-date=September 1, 2015 |website=[[RabbitEars]]}}</ref>
|-
! [[Digital subchannel#United States|Channel]]
! [[Display resolution|Res.]]
! [[Aspect ratio (image)|Aspect]]
! Short name
! Programming
|-
! scope = "row" | 9.1
| [[1080i]] || [[16:9]] || WGN || Main WGN-TV programming
|-
! scope = "row" | 9.2
| rowspan="4" |[[480i]] || [[4:3]] || Antenna || [[Antenna TV]]
|-
! scope = "row" | 9.3
| rowspan="3" |16:9 || Grit || [[Grit (TV network)|Grit]]
|-
! scope = "row" | 9.4
| Rewind || [[Rewind TV]]<ref name="RewindTV">{{cite web |url=https://www.nexttv.com/news/nexstar-to-launch-rewind-tv-digital-channel-airing-classics |title=Nexstar to Launch Rewind TV, Digital Channel Airing Classics |last=Lafayette |first=Jon |work=Broadcasting & Cable |date=April 26, 2021 |accessdate=July 10, 2021}}</ref><ref name="RewindTV2">{{cite web |url=https://www.nexstar.tv/nexstar-media-inc-to-launch-rewind-tv-on-september-1/ |title=Nexstar Media Inc. to Launch "Rewind TV" on September 1 |work=Nexstar.TV |date=April 26, 2021 |accessdate=July 10, 2021}}</ref>
|-
! scope = "row" | 9.5
| TBD || [[TBD (TV network)|TBD]]
|- style="background-color:#DFEBF6; border-top: 2px solid #003399;"
! scope = "row" | [[WBBM-TV|2.1]]
| 1080i || 16:9 || CBS2-HD || [[CBS]] ([[WBBM-TV]])
|}
{{legend|#DFEBF6|Broadcast on behalf of another station}}

The main 2.1 subchannel of WBBM-TV is also broadcast on the WGN-TV multiplex; WBBM-TV, Chicago's high-power [[ATSC 3.0]] (NextGen TV) station, carries WGN-TV in that format.{{r|rei}}

===Analog-to-digital transition===
WGN-TV began transmitting a [[digital terrestrial television|digital television]] signal on UHF channel 19 on January 4, 2001, operating from a transmitter located {{convert|1,486|ft|m}} atop the [[Sears Tower]]. (Incidentally, WGN-TV was one of six, originally eight, Chicago television stations that declined offers to move their analog transmitters to the Sears Tower antenna farm ahead of the building's 1973 completion.)<ref>{{cite magazine |title=8 Chicago TV's reject Sears plan |periodical=Broadcasting-Telecasting |page=54 |date=May 8, 1972}}</ref><ref>{{cite magazine |title=In Brief: Staying put. |periodical=Broadcasting-Telecasting |page=5 |date=October 29, 1973}}</ref> The station shut down its analog signal, over VHF channel 9, on June 12, 2009, the official date on which full-power television stations in the United States [[Digital television transition in the United States|transitioned from analog to digital broadcasts]] under federal mandate. The WGN-TV digital signal continued to broadcast on its pre-transition UHF channel 19, with digital television receivers continuing to display WGN-TV's [[virtual channel]] as its former VHF analog channel 9. As a consequence, WGN-TV permanently ceased transmissions from the John Hancock Center's west antenna tower, establishing its existing digital facilities at the Sears Tower digital antenna as its main transmitter.<ref>{{cite web |title=DTV Tentative Channel Designations for the First and the Second Rounds |url=http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-06-1082A2.pdf |publisher=[[Federal Communications Commission]] |access-date=March 24, 2012 |url-status=live |archive-url=https://web.archive.org/web/20130829004251/http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-06-1082A2.pdf |archive-date=August 29, 2013}}</ref><ref>{{cite web |title=CDBS Print<!-- Bot generated title --> |url=http://fjallfoss.fcc.gov/cgi-bin/ws.exe/prod/cdbs/forms/prod/cdbsmenu.hts?context=25&appn=101231326&formid=387&fac_num=72115 |publisher=U.S. Federal Communications Commission |access-date=March 24, 2012}}</ref>

Though not a participant in the [[SAFER Act]], WWME-CA carried simulcasts of WGN-TV's 9&nbsp;p.m. newscast—except in the event of sports delays—and WMAQ-TV's morning and early evening newscasts until July 12 to provide an analog "lifeline" for viewers that were unprepared for or who had reception issues following the digital transition.<ref>{{cite news |title=WMAQ-TV, WGN-TV partner with Weigel Broadcasting for analog 'lifeline' |url=http://newsblogs.chicagotribune.com/towerticker/2009/06/wmaqtv-wgntv-partner-with-weigel-broadcasting-for-analog-lifeline.html |author=Phil Rosental |newspaper=Chicago Tribune |date=June 11, 2009}}</ref><ref>{{cite web |title=WCIU, WMAQ, WGN Form Chicago 'Lifeline' |url=http://www.tvnewscheck.com/article/32976/wciu-wmaq-wgn-form-chicago-lifeline |website=TVNewsCheck |date=June 11, 2009 |access-date=September 1, 2015}}</ref><ref>{{cite news |title=Weigel's Analog Nightlight Could Help Chicago Stations With Reception Issues |url=http://www.broadcastingcable.com/news/technology/weigels-analog-nightlight-could-help-chicago-stations-reception-issues/46911 |author=John Eggerton |periodical=Broadcasting & Cable |date=June 17, 2009}}</ref>