In Anytone 578 to be able to receive the GPS signal I have to use the external, mouse style GPS antenna. For me it is just another piece of unnecessary bit attached to the radio. The good news is that the radio was originally designed with a small room for the integrated GPS antenna hidden in the plastic, front panel of the radio.
The very first question is how much better is the external antenna, comparing to the one I decided to use? The very quick and simple answer is in a normal use I have not found ANY difference. With the external antenna I had to wait about 15 seconds to start receiving the GPS signal and now, after the replacement to the internal antenna I have to wait exactly the same time. So if you want to follow what I did, I hope the pictures below will help you to go through the process of adding the internal GPS antenna to the Anytone 578. The room inside of the front panel pocket for the integrated antenna is 19×7 and 20mm deep. So I used 18×18 square antenna which is 6mm thick.
Specification of the antenna is shown below, however, what you need is any active (with amplifier inside) GPS antenna, working @ 1575MHz and with IPX (u.FL) connector. The cost was £1 for the antenna and £1 for shipping from China to the UK.