Dc 40 losing gps signal

[Rocketdeerdog]

I have a dc 40 that I bought used over a year ago from a fellow I didn't know. Ever since I have had the collar it loses gps signal about every other time I use it. I have no way of know exactly how old it is so I'm not sure if it's one of the earlier collars that had this problem from the factory. My question is am I better off sending it in for refurb or having the gps antenna mod done by DU? What is the turn around on the antenna mod from DU?

Thanks
Randall