Editing RCA connector (section)

==History==
[[File:RCAradio45EMback.JPG|thumb|Rear panel of a 1939 RCA model 45EM [[vacuum tube]] desktop [[AM radio]] with a female RCA jack.<ref>{{cite web |title=1939 RCA Model 45EM AM Radio |url=https://www.radiomuseum.org/r/rca_45em_45_em_ch_rc_435a_rc4.html |website=Radio Museum |access-date=January 5, 2021}}</ref> Tag reads "An inexpensive RCA Victor record player will make a fine [[Victrola]] of this radio. Plug here."]]
The exact release date of this connector is still a little vague.  The following dates were derived from historical RCA documentation.

By no later than 1937, RCA introduced this connector. In 1937, it was used inside a RCA model U-109 [[AM radio|radio]]-[[phonograph]] and model R-97 phonograph.  In the U-109, the internal amplifier chassis had female connectors which accepted male cables from the internal radio chassis and built-in phonograph player.<ref>{{cite book |url=https://worldradiohistory.com/ARCHIVE-RCA/RCA-Service/RCA-Victor-Service-Notes-1937.pdf |title=RCA Victor Service Notes for 1937 Broadcast Radio Receivers, All-Wave Radio Receivers, Phonograph Combination Instruments, and Miscellaneous Service Information |edition=1st |publisher=RCA Manufacturing Company |chapter=Model U-109: Sixteen-Tube, Three-Band, A-C, Radio-Phonograph |page=256}}</ref><ref>{{cite book |url=https://worldradiohistory.com/ARCHIVE-RCA/RCA-Service/RCA-Victor-Service-Notes-1937.pdf |title=RCA Victor Service Notes for 1937 Broadcast Radio Receivers, All-Wave Radio Receivers, Phonograph Combination Instruments, and Miscellaneous Service Information |edition=1st |publisher=RCA Manufacturing Company |chapter=Models R-96 and R-97: Three-Tube, A-C, Electric Phonographs |page=290}}</ref>  Originally, the concept was intended as an easy method to unhook sources while [[troubleshooting]] the console during servicing.{{Citation needed|date=January 2021}}

By no later than 1938,<ref name="RCA-GT-1939">{{cite magazine |url=https://worldradiohistory.com/Archive-Early-Radio-Assorted/RCA-Globetrotter-1939.pdf |title=Improved Electric Tuning For All Is Keystone of New RCA Victor Standard Line of Domestic Models |first1=Paul |last1=Richardson |magazine=RCA Globe Trotter |date=June 1938 |volume=2 |number=3 |page=15}}</ref> RCA migrated the female connector to the rear panel of many of their desktop AM radio models to allow customers an easy method to attach an external phonograph or television at a later date.<ref name="SC-440M">{{Cite web |url=https://antiqueradio.org/StrombergCarlson440M.htm |title=Stromberg-Carlson Model 440M Console Radio (1939) |website=Phil's Old Radios}}</ref>  The connector was labeled on the back of radio with one of the following terms: "[[Victrola]]", "[[Phonograph|Phono]]", "Pick-up", "Television".<ref name="ET-EET"/><ref name="RCA-TT5-DS">{{cite web |url=https://www.earlytelevision.org/pdf/rca_tt5_dealer_sheet.pdf |title=RCA Victor Television Attachment Model TT-5 |type=Dealer sheet |date=1939}}</ref>  RCA later marketed a special turntable for [[Gramophone record|45 RPM]] records, the model 9JY.<ref>{{cite web |url=http://www.blueboyrecords.com/record-player/rca-45-rpm-9-jy-record-player-and-rca-tube-radio-6-xd-5 |title=RCA 45 RPM 9-JY Record Player and RCA Tube Radio 6-XD-5 |publisher=BlueBoy Records |access-date=2011-08-23 |url-status=dead |archive-url=https://web.archive.org/web/20110910211432/http://www.blueboyrecords.com/record-player/rca-45-rpm-9-jy-record-player-and-rca-tube-radio-6-xd-5 |archive-date=2011-09-10 }}</ref>

In 1939, RCA introduced two [[AM radio|radio]]-[[television]] floor consoles (TRK-9, TRK-12) which used the same internal connection concept but the audio output of the television chassis was connected to the radio/amplifier chassis via a male to male cable.<ref>{{cite book |url=https://worldradiohistory.com/ARCHIVE-RCA/RCA-Service/RCA-Service-Data-1938-1942-C.pdf |title=RCA Victor Service Data Volume II: 1938-1942: Radio Receivers, Phonographs, and Television |publisher=Radio Corporation of America, RCA Victor Division |edition=1st |date=1944 |chapter=Models TRK-9, TRK-12, TRK-90, and TRK-120: AC, Superheterodyne, High-Picture-Definition, Five-Television-Channel, Receiver and Three-Band, Electric Tuning, AC, Superheterodyne Broadcast Receiver |pages=261{{hyphen}}C, 275{{hyphen}}C}}</ref> Three lower-cost 1939 television models had an audio output connector on their rear panel instead of an integrated amplifier and speaker: RCA TT-5, Westinghouse WRT-700, GE HM-171.<ref name="ET-EET">{{Cite web |url=https://www.earlytelevision.org/wireless_tv_sound.html |title=Wireless TV Sound |website=Early Television Museum}}</ref><ref>{{Cite web |url=https://www.earlytelevision.org/rca_tt-5.html |title=RCA TT-5 |website=Early Television Museum}}</ref>

In the 1950s, RCA connectors began to replace the older {{convert|1/4|in|mm|2}} [[Phone connector (audio)|phone connectors]] for many other applications in the consumer audio world when component [[high-fidelity]] systems started becoming popular during the transistor revolution.{{Citation needed|date=January 2021}}  Refinement of the RCA connectors came with later designs, although they remained compatible.{{Citation needed|date=January 2021}}

In the 1980s, some computer monitors<ref>http://www.bitsavers.org/pdf/zenith/monitor/585-033-1_ZVM-122_123_Video_Monitors_Service_Manual_1983.pdf</ref><ref>http://www.apple-iigs.info/doc/fichiers/AppleColorCompositeMonitorOwnersGuide.pdf</ref> and TVs had a RCA jack for composite video input.<ref>Sony KV-1965 television</ref><ref>{{cite web | url=https://archive.org/details/kv-2501/page/n6/mode/1up | title=Sony KX-2501 Service Manual }}</ref><ref>{{cite web | url=https://archive.org/details/sonykv25xbrservicemanual | title=Sony KV-25XBR Service Manual }}</ref> These were typically high end TVs for the time, a notable example being the Sony ProFeel line.<ref>https://www.worldradiohistory.com/Archive-Poptronics/80s/1983/CE-1983-06.pdf</ref> While in theory this improved image quality by eliminating the need for an RF modulator, when connecting devices such as VCRs and computers, there was no guarantee for higher image quality.<ref>https://books.google.com.pa/books?id=ZOQDAAAAMBAJ&pg=PA82&dq=video+input+monitor+vcr+1983&hl=en&sa=X&ved=2ahUKEwjL-oyfyZyNAxW2QzABHZPAHE04RhDoAXoECAsQAw#v=onepage&q=video%20input%20monitor%20vcr%201983&f=false</ref> Later, some televisions had RCA jacks for audio and video out<ref>https://www.sony.com/electronics/support/res/manuals/W000/W0006260M.pdf</ref> or component video inputs.<ref>https://www.sony.com/electronics/support/res/manuals/3860/38603712M.pdf</ref><ref>Pioneer Service Manual. LD DVD player DVL-909.</ref>