TL;DR: you definitely need a modified firmware, you can download it here and flash it on Chrome/Chromium using this tool. Set the RX modulation to „DIGI“, bandwidth to „WIDE“. A hardware mod might be required, your mileage may vary. For more details, keep on reading.

Quite widespread nowadays, the UV-K5 is a fantastic platform for many experimentation. However, fast (aka 9600 baud or flat audio) data was out of reach as the filters and pre/de-emphasis was always on by default, same as many other Chinese radios. So no DMR, NXDN, M17, DSTAR… Or POCSAG!

However, some time ago, Rob Riggs WX9O from Mobilinkd figured out how to modify the radio's registers and hardware filters to get a very flat audio response from this radio. More details here and here.

This is perfect for almost all digimodes… Except POCSAG! Sadly, even with those mods, the radio doesn't have the required deviation (+-4.5kHz) for DAPNET.

This is just a matter of tweaking the registers of the RF chip. … Specifically this exact line.