I have an SLX1 bodypack system, but I don't like the push button operation of the pack. I would rather have a more tactile toggle switch so I can tell if it is on or off by touch. Can I substitute a BLX1 transmitter and use it on the SLX4 receiver?
Sorry, the answer is no. BLX transmitters cannot be used with SLX receivers.
Even though there is an overlap of operating frequencies, the audio companding circuits are different and the "hybrid" system would not work properly.