Most SWR meters will be accurate at 4-5 watt ranges...When you start dealing in the hundreds you might want to switch to a Bird or MFJ meter...The old Cap and Resister mod is the fav for most Mudducks...you can even add an adjustable mod to this by adding a variable resistor or unused knob like the Clarifier knob on a non SSB Cobra 29LX radio...haha...(What a waste of a perfectly good knob) to connect to the resistor points on the bottom of the board of the Cap and Resistor mod.