I wouldn't program the PL tone at least not at first, if at all. The only time the PL tone might be useful is if there are multiple agencies using the same frequency, in that case each agency would have a different PL tone and you could use the PL tone to keep from hearing agencies you are not interested in. In your case I don't see anyone else using the 155.76 frequency so you will hear the same traffic whether you program the PL tone or not. If you do need the PL tone I would program the frequency without a PL tone at first to make sure you can receive what you want to receive then you can add the PL tone later if needed. 155.76 is the only frequency in the database with a PL tone, the other frequencies do not use a PL tone.