I've always programed mine with the computer, that is how I add and delete programs. How did you program yours, by hand? If so I'm not sure how to delete a frequency but you could always lock it out.
FYI if your looking for the best antenna for the pro-137 check out the MH-255 at https://www.webtrix.net/shopcart/Ad...pringgreen>Handheld+Radio+Antennas</b></font> It works fantastic on this scanner.