Hi Mark (and hopefully many others about to respond!)
I'm not sure if WHNZ was all news, they could have been, but I do know they had at one point in time, 570 WHNZ had a four hour morning newsblock, a 90 minute or two hour midday news block, as well as an afternoon/evening newsblock. This would have been in the mid 1990's.
A year or so ago, Pittsburgh (which is a smaller market than St.Pete/Tampa or Ft. Lauderdale/Miami) had an all news outlet; so it is amazing that some market in Florida doesn't have one, unless you count the one in Pensacola on the extended band.
Back in either 2002 or 2003 when WFTL - 850, West Palm Beach first kicked in with their new powerful signal (believe their call letters were different then) they were advertising that they were going to be an all news statio and I think that lasted a few months, before they starting slipping in talk shows, and eventually it was all talk.
There was a mention, I believe on the site's home page today, that WINS 1010 and WCBS 880 are the top rated two stations in the latest NY ratings. (WCBS being number 1); on WINS same frequency is another 50,000 watt (east west directional) station owned by WCBS that is floundering, I wish CBS would consider an ALL NEWS format, even if it meant simucasting WINS 1010 out of NY all or even most of the day, with local news breaks. Local news on the radio is sadly lacking in the St. Pete/Tampa market; the number one rated AM station WFLA talk/news supposedly doesn't even do live local news after 7pm, everything after 7pm and overnight is pre-recorded.
drt