Batboard

We have a number of HMN1090A through D mic’s. Some of our 1090A mic’s do not have the jumper (JUX) on the internal circuit board inside the mic to allow hot mic operation during an ERTT. Does anyone know if this was an option when ordering the mic or a random mistake by Motorola? Also, does anyone know if the models 1090B through D may have the jumper omitted?

If you PM me with your email I can send you a pic with the mic circuit board jumper

Fineshot1, thanks for your reply. I am very familiar with the physical jumper on the circuit board. I am trying to find out how we ended up with mic’s that did not have the jumper installed. Was it an option when we ordered? I don’t do the ordering so I don’t know if this was an option?

Sorry - I can't help you. I do not know if this jumper was an option or not
and I could not find any doc's on this mic.

Thanks for looking!

The A version HMN1090 microphone did not have an orderable option to allow 'Hot Mic' operation. This would have required a different circuit board which would automatically have been up-suffixed to a B version model. The B version and later HMN1090 microphones do include the jumper which allows a radio with the proper firmware to control and utilize the 'Hot Mic' feature.