I have a 10 year old ELK-M1G security system that has two older ELK-M1XRFTW Elk 2 Way Wireless Transceivers installed. One of the Transceivers appears to have failed and no longer appears to be working. I plan to purchase a new improved ELK-M1GXRFTWM Elk 2 Way Wireless Transceiver (which is designed for multiple transceiver systems) to replace the older failed ELK-M1GXRFTW one. I would like to know if I can install the new multiple transceiver ELK-M1GXRFTWM in the same system with the older ELK-M1GXRFTW transceiver. Will this cause a problem mixing the two or must I buy two new improved ELK-M1GXRFTWM transceivers?