What is RG174?

RG174 is an extremely common Coaxial cable type, typically used in GPS, WLAN, and cellular communications as its 2.5mm outer diameter allows for the attachment of most micro-coaxial connectors (such as MMCX, MCX, TS9, SMB, etc.).

Is rg58 double shielded?

If you have to use coax then look at RG-393 or RG-214 for the large diameter (i.e RG-8 / RG-213 size) and RG-142 or RG-400 (RG-58 size). All are double shielded with silver plated shields and will not cause duplex noise.