gr8oldies said:
Seeing as I've never been to Cancun I'm not much help, but I heard anumber of Mexicans from sarasota, FL, so I wouldn't be shocked to hear anything from Florida's West Coast that might have a westerly pattern. WWL should be easy if there's no locals on 870.
I would have replied sooner, but am just seeing this......
About WWL, I think their tx is voluntarily directional AWAY from the Yucatan. So, it won't be as easy to catch them as you think. It's one of the reasons that they come in so well across the US - because they don't waste as much wattage over the Gulf.
Try for the big Chicago signals (WSCR, WBBM, WGN, WLS) as I've pulled them in within the Caribbean basin. Others to look for would be WBAP 820 Ft. Worth, 1080 KRLD Dallas, WHAS 840 Louisville, WSB 750 Atlanta, and WLW 700 Cincy. Also, certain Tampa Bay area stations should come in well (try 970).
The various frequencies of Cuba's Radio Reloj should be messy - but audible. Try 570 and 790 (1020 is another, I think) and listen for the ticking of the clock, with a beep at the top of each minute, followed by six beeps that form the morse code for "R R". Those tones seem to break through most interference. Each frequency comes from a different part of Cuba - you'd need the World Radio and TV handbook and an atlas to figure out which comes from where.
Look and see if you can pull in any of the NY area stations. I have not had good luck with ANY east coast signal in the Caribbean area - only in Puerto Rico and that was sporadic. Even there, Chicago was an easier pickup.
830 could also be an interesting frequency - do you get WCCO from Minneapolis or Venezuelan radio from Caracas? Both are possible catches there - but Caracas is the better bet.
Enjoy the nice weather and good luck with DX!