Hi Larry -
the material you got has about 3db atten around 400mhz.
Thicker 3M material with attenuation at lower frequencies was lots more expensive,
and attenuation seemed mostly proportional to thickness.
I did not expect much to happen at 12kHz..
The material appears to have no appreciable effect from 110kHz - 300MHz,
but does help from 500-1000MHz.
Whacky stuff happens 1000-1100MHz, then material helps until 1200MHz or so.
My unit does not calibrate usefully, with or without EMI material, above 1200MHz.
Oristo
