Does anyone have the tone-out freq's for Durham EMS? I can't seem to properly read the first tone (e.g. I get 563 one day, 570 another, etc) but I believe the second is 1287Hz. Any help is appreciated.
As I am sure that you have found by looking, there is no central lists for tone frequencies like there is for frequency information. Some places might be listed someplace, and these places are only because someone has already got that information and has posted it.
I take it that you are reading these tones via your scanner. While this is a very nice feature on some higher end scanners, I have found that finding the values for your tone sets can vary somewhat using this method. While the scanner might have this feature, it will usually get you close but many times not right on the exact frequency; it just not designed to do better than that.
I checked the frequencies that you have posted (in my pager programming software) and found that there are 2 absolute frequencies closest to what you are asking about: 553.9 and 569.1. I would try plugging in the 569.1 and trying that one first.
And also remember that any scanner that has tone out capability is not going to be anyplace near as tight on the tone frequency requirements as a pager is. This is one reason why you are seeing the variations in the tone frequencies at different time. It will get you 'close', but not right on. And that is true if you are reading tones, or using the tone out feature to receive them.
Play around with this a bit and you will probably be okay (it will work). If not, keep playing around with it. The only way you are going to know for sure is when the agency gets a call and the tones go out over the air. If it's a quite agency, well that might take some time until their next call or tone test.
Good luck!