On 24/12/2017 19:38, Murmansk wrote:
If you go and look on the Ultimate Handyman Forums there is a sub-forum there populated be people who know all about alarms - you should be able to get some good advice there from people who know all about the subject


Thanks. I hadn't heard of the UHF forums but I've asked on the
"electrical" forum (I couldn't find one dedicated to alarms, only alarm
manuals).

Whilst browsing I discovered Alarm Mines - a brilliant idea for wild
camping :-)