To add to the confusion a little. Has anyone noticed the change in coil (or
loop) Q that is going to occur over temperature ? By my reckonning, over the
temperature reange 0 deg to 40 deg (in a shed in a hot summer) the DC copper
resistance will go up by 16%. (temperature coefficient of Cu at 20 deg =
0.0039, delta R = 1.0039 ^ 40)
Assuming RF loss is only related to skin depth, and this changes as the square
root of resistivity that suggests coil Q could to be 8% higher on cold winter
days.
I know coil losses are usually swamped by ground losses, but it may just be
observable by loop owners.
Andy G4JNT
|
