When I got home it was a simple matter to check the Arbitron data on the two possibilities and determine which one I heard. It turned out it was WPDM-1470, out of Potsdam, NY. The weaker station was WNYY-1470 out of Ithaca, NY. The Potsdam catch was the better of the two, and at lower power too. I would not have been able to determine this without the ability to check station formats.
I've covered the availability of station lists for mediumwave DXers in two previous articles on RADIO-TIMETRAVELLER, Mediumwave Station Reference Lists and Mediumwave DX Meets The Tablet Computer. Many of these lists don't document station formats. Those that do may be out of date, or incomplete. And that's just for US data - information for Canada is even more suspect. This is not surprising considering the frequency at which stations change formats.
Those lists that do document station formats are Lee Freshwater's AM Logbook (perhaps the most complete), Topaz Designs, and presumedly the National Radio Club's AM Radio Log (though at a steep price - currently $28.95 for non-members and out of print). radio-locator - technically not a list site, but you can generate a list from this link using search parameters - will also provide a nice custom list of stations which includes format information. It seems fairly complete.
Virtually all US and Canadian stations subscribe to Arbitron. Arbitron, of Columbia, MD, is an international media and marketing research firm serving all types of media — radio, television, cable, etc. It is Arbitron's business to measure network and local market radio audiences across the United States, survey the retail, media and product patterns of U.S. consumers, and provide measurement and analytics. This includes, of course, what formats stations are using. It is probably the most up-to-date format reference of all.
The Arbitron Radio Station Information Profiles (SIPs) contain information about all radio stations in the United States: current addresses, station names (including call letters), frequencies and formats. Many if not virtually all Canadian stations are also represented in the profiles.
So how do we use Arbitron to identify station formats? Though the Station Information Profile used to be made directly available on their web site, lately the link has been moved to a members only site, My Arbitron. However, still buried deep within the Arbitron's main web site are a couple of links which can get us our needed information.
Stations are asked to update their Arbitron reference data four times per year. This goes into a seasonal "survey". We must take an educated guess of the current season on file that we wish to extract information from. Survey codes are:
- WI (winter)
- SP (spring)
- SU (summer), noted as SU12 in the example (12 = current year, 2012)
- FA (fall)
Using the call letters of the station, compose a link for the AM broadcast service as such:
Note the use of the surveyID=SU12 (summer of 2012), and callLetter=WHAM fields. You can also check FM stations by substituting the band=fm field.
A station search page is accessible as well, if you know the current survey season and date:
Old surveys do not seem to be accessible. Use the current season and year, or sometimes the season just past if the current season is not yet up for inspection.
Keep trying with your link until you have success. I have found the Arbitron site to be quite busy at times. During busy periods, it also may return a "survey not found" message. Persistence is good.