We have just one more thing to check, and we're done. If a second receiver shows the same relative levels, your transmitter probably has a problem in its pre-emphasis circuit, and needs to be serviced. That's all there is to it. You can even send a packet and see what that looks like. Tune to a busy packet channel and listen for the loudest sounding packets.
Most communities have at least one station whose packets sound obnoxiously loud.
If you assume that the loudest stations you hear have deviation of 6-7 kHz you can even verify your own meter calibration. Look for a voltage reading of 0.6 to 0.7 VAC when the obnoxiously loud, distorted station is transmitting. Since packets usually last only about 1 second, it may be difficult to read a digital VOM while the packet is being transmitted. If your VOM has a MAX reading feature or bar-graph feature, this will be helpful. An analog VOM or an oscilloscope would also make this measurement easier.