The specification requires a pull up resistor and a diode end of discussion. To say it's not needed is careless and could damage someone's radio. There is simply no need to be ignorant and defensive.
I was typing my long winded reply outside in a hot tub. I work with 1000s of different models and do not know the radio pinout off the top of my head. Regardless of what line it uses the radio requires an external pull up resistor. I had to say something before others copy you and make the same mistake.
What do I know, I only run a business that manufactures programming cables and interfaces, repair amatuer and professional radio equipment, amongst many other things.
