I would say that News/Talk is actually more than one format.
Format A in Chicago would be WGN. This is a format that has talk shows surrounding extensive news coverage. At the biggest stations this means 24/7 local news, in medium markets this might mean 6am-mid local news, in a small it could mean 6a-6pm, or drive times only. Unless they're O-and-O's, and sometimes even if they are, they won't carry network news as the top of the hour. These stations most often carry Rush Limbaugh, or a local talk show. They generally won't carry O'Reilly. They'll generally be amongst the highest-rated in a market. (If they weren't, the station wouldn't pay for a news staff.) It's rare to have more than one such station to a market, but you might find it that in very large markets. They often carry sports, particularly and especially especially major league baseball if it is a factor in that market. Format A stations are likely to have lots of conservative talk, though some have none, but the vast majority have other kinds of talk shows as well... either libertarian, liberal, hot-talk or social issues shows, advice type shows, Coast-To-Coast AM. A lot of these staitons 20 years ago were full service AC or even Country stations that had music with lots of interruptions for good local news coverages, good disk jockeys, and lots of commercials.
Format B is a format with little or no local news. They might have local news in the morning, possibly even tons of it, but the rest of the day very little local news. These stations almost invariably carry network news at the top of the hour. In the biggest markets they might have local news updates quite a few hours a day, perhaps a minute or two at the end of a shortened network news. Or they might have brief local news updates produced by a local TV station. Or they might have no local news at all, even in the largest markets. These stations typically would get lower ratings than in format B, and there often would be several to a market, in some markets a whole bunch of them. WLS is could be described as format B, or perhaps because of its local elements it deserves to be classified as Format A. Sports radio stations really fit into this format, but in radio terms, they are already recognized as a separate format. Format B has some pretty clear variants.
B1- Mainstream right-dominated talk using whoever's available after the local Format A station gets what it wants. Often O'Reilly, but Limbaugh if he's available. Hannity if the local format A station doesn't have Hannity, Glen Beck maybe. Likely to have a modest local news presence running much of the day. Might have financial or social advice. Fairly rare to ave more than one station like this in a market. Often a local morning show.
B2- Hard right wing talk. Michael Savage, Liddy if he's still out there. The third-rated right wing talk station in a market, or the second rated if the local Format A station is really right wing. Rarely a local morning show. Rarely local news. Always national news on the hour.
B3- Socially oriented right wing talk. Think some Salem stations.. Bill Bennett, Medved. NAtional news on fhte hour. Could be from USA Network.
B4- Progressive talk. Little local presence outside morning drive or weekends. National news on the hour, from any mainstream network. (Is there still an Air America News. Does anyone carry it now?). Could be local news updates from a sister newsroom.
B5- Variety political talk-- could be O"'Reilly at Noon, then Ed Schultz, little local presence except morning drive. Natl news.
B6- Service talk-- Financial advice, psychological advice, computer advice. Rare for this to get it's own station, common to have a chunk of a station in a format described above, especially on weekends. Big emphasis on selling to targeted advertisers rather than onm overall ratrings. Might be brokering airtime. (IMHO, this kind of programming is what helps some Format A or Format B1 stations to reduce their ratings on weekends in exchange for some quick cash.) WOR in New York is what I call a Format A station, but it has big elements of this format. Probably natl news on the hour.
B7- Sports. As said above, industry recognizes this as separate format, as well it should, but clearly it fits the patttern described here, minus the top of the hour news. Probably a sports news update on the hour, maybe several times an hour.
