just pick up a 2510 on my travels it transmitts fine great audio and rec.... but the rf stays 6 on the meter and and no sound but if i key up my mobile in the yard you can here me fine play with sq doesn't help its like the sq is on or the rf knob isn't working because when turned down the meter stays the same . would like to put in truck. it is missing swr cal knob would lke to replace that to