I just installed a CVR wireless voice release on the trap field at the club last weekend. Tried installing the receiver inside the traphouse, and that didn't work very well (not all the transmitters were detecting the receiver). Ended up having to set the receiver by the side of the house, then it worked perfectly.
Given the winters we have up here, it doesn't give me warm fuzzies either attaching it externally to the house (unless we can devise some sort of weatherproof and blastproof housing), or bring it out and setting it on the ground every time someone wants to use the system (in the snow/rain/sun).
Is there any way to attach an external antenna, so just the antenna can be on the outside of the house, and the actual receiver unit can remain inside?