At 12/21/2008 14:01, you wrote: >I moved over to utilizing the PTT instead of the thermostat disks after I'd >had a few thermostats fail. But I agree with your thinking.
My thoughts as well: the thermostat is an elegant solution, but if it fails, your repeater fails in a rather expensive way. One reason why I've dismissed using any switching on my 110 V cooling fans & let them spin 24/7. The 12 V fans get switched by PTT, though I use a separate buffer transistor to key them. Otherwise the fan motor dumps noise onto the PTT line, which finds its way into the TX audio. You could wire two thermostats in parallel so if one opens up you don't lose cooling. However, to be an effective safeguard against failure they should be independently tested when doing your PM. Bob NO6B
