In 1989, an agreement was made between album rock station WBLM, which at the time was broadcasting on 107.5 FM, and WTHT to swap frequencies while retaining their respective call letters.

This swap was intended to give WBLM a significantly stronger signal in Portland, as well as Central and Southern Maine, Eastern New Hampshire, and Northeastern Massachusetts; however, once the swap was complete, WTHT lost a significant amount of coverage, especially in extreme Southern Maine and Southeastern New Hampshire.

In fact, during the summer tropospheric ducting season, WTHT often suffered from significant interference from WFCC-FM in Chatham, Massachusetts, also on 107.5 FM.

Once the swap with WBLM was complete, WTHT re-branded themselves as "Thunder 107", and retained their CHR format with a bit of a rhythmic lean, which was popular at the time.

Over time, WKZS adjusted its presentation to become a Hot AC, and in March 1997, the station reimaged to become "Mix 96.9 and 99.9", with the call letters WMWX following.

[6][7] On January 1, 2024, WBQQ split from its simulcast with country-formatted WTHT and launched a soft oldies format, branded as "99.3 The Wave".

As of April 2013[update], W245AA began serving as a repeater of WTHT's HD2 channel, which simulcast the WBACH classical music format of Thomaston sister station WBQX.

This returned the format to Portland for the first time since the 104.7 FM frequency became rhythmic top 40 station WHTP in September 2012.