KKRZ (100.3 MHz) is a commercial FM radio station in Portland, Oregon, known as Z100. It is owned by iHeartMedia and airs a Top 40 (CHR) radio format. The studios and offices are on SW 68th Parkway in Tigard. Z100 carries two syndicated shows on weekdays, "Johnjay and Rich" in morning drive time and Ryan Seacrest in middays. Local DJs are heard in the afternoon and evening. KKRZ has an effective radiated power of 100,000 watts, the maximum for most American FM stations. The transmitter is in Portland's West Hills, off NW Skyline Boulevard. KKRZ broadcasts using HD Radio technology. Its HD-2 digital subchannel carries an alternative rock format known as "Alt 102.3." That signal feeds 99-watt FM translator K272EL at 102.3 MHz. History KGW-FM, KQFM The station first signed on as KGW-FM, on . It originally broadcast on 95.3 MHz. KGW-FM moved to 100.3 MHz, on September 22, 1947. It mostly simulcast its AM counterpart, 620 KGW (now KPOJ). The two stations were owned by Portland's top daily newspaper, The Oregonian. KGW-AM-FM were network affiliates of the NBC Red Network, carrying its dramas, comedies, news, sports, soap operas, game shows and big band broadcasts during the "Golden Age of Radio." The call sign changed to KQFM on December 1, 1954. At first, KQFM aired a "good music" format of softer popular songs. This evolved over time to an easy listening format known as "Q-Music." The station played mostly instrumental cover versions of popular songs, as well as Broadway and Hollywood showtunes. In 1978, KQFM switched to a progressive rock sound under the name "Q-100". The following year, the station was acquired by Golden West Broadcasting, owned by singer-actor Gene Autry. Golden West already owned KEX, so the two stations were managed and operated together. KQFM's format was changed to oldies on March 16, 1981 as "Solid Gold FM-100." Z100 On November 2, 1983, the station changed to the KKRZ call letters and switched to a Hot Adult Contemporary format as "The Rose," playing off of Portland's nickname as "The Rose City." KKRZ began its current Top 40 format on March 16, 1984, widely mirroring co-owned WHTZ in New York City (including the moniker familiar "Z100" name). In 1986, the station adopted a more rhythmic-leaning format due to the lack of an existing urban contemporary station in Portland. In 1999, KKRZ picked up competition from Adult Contemporary-formatted KXL-FM, who flipped