To wire a positive ground lavaliere mic (some older TRAM's and Sony's) to the new servo input used on the SM series and the new UM400a, LMa and UM450 transmitters, use the following wiring arrangements. (Positive ground lavalieres are also known as negative bias lavalieres.)
This is the simpler "servo only" wiring and is not compatible with older Lectro transmitters (UM200, UM400, etc.)
The following is the compatible wiring and requires an external resistor but this wiring can be used with all Lectrosonics transmitters, old and new.
Other value resistors can be used in a pinch from 2k to 4k, including the 3.32k resistor that we provide in the 5 pin wiring kit.