P25 Radio GPS & Portable Antenna Question

[CommunicationsAlways]

I purchased a P25 multi-band portable radio with GPS satellite capabilities, but it only works with the GPS antenna attached to the speaker microphone (which I don't have now, but will purchase and cost around $300). Since the only information I need is latitude, longitude and altitude of a location, but don't need the mapping capability because I use paper or e-maps/charts about the local/region. That leaves me to wonder if it would be a good investment?

The other questions is some locations in the mountains were I travel there is very... bad VHF, UHF coverage (136-174 up to 512 MHz which are used). Would a 13+ inch whip antenna provide better coverage to contact aircraft in VHF-AM, VHF-FM, UHF and repeaters in those areas (I know that in a deep valley that would be impossible) when compared to a 6 inch portable antenna? If so what brand of antenna/s do you recommend?

I'm open to any suggestions.

[FireCpt809]

What radio are you talking about ? Not too many do AM air and FM P25

[CommunicationsAlways]

What radio are you talking about ? Not too many do AM air and FM P25

Thales Liberty. Specifically looking for coverage in 136-174, 380-520 MHz.

[CommunicationsAlways]

Has anyone found or know where to buy a Thales Liberty GPS speaker mic, or a third party P25 GPS mic? Radio already has feature enabled, and Thales will not be manufacturing new GPS speaker mics.