We have several teletectors by WB Johnson and Assoc. models 2000w and 1000w that have the same problem.
The readings are affected by whether or not you have the audio on. We normally calibrate them with the audio off, so haven't noticed this until recently.
I checked our other units and some of them behave the same way. On certain ranges the audio causes the readings to double or triple.
I know it is noise/crosstalk, but am just wondering if anyone has seen this before. The audio on these is a 140VAC burst, not sure why, but the noise can be seen all over the circuit.