HF radiation from any electronic device has to be below 50 mV in the HF spectrum at 100 yards away to a reference antenna.
Can you provide a reference for this requirement?
It is an aberrant reference.
Part 15 specifies radiated emissions for a given frequency range in the field strength form of μV/m at a specified distance. Specific emission limits are determined by the device classification but it is instructional to look at the field strength limits for the HF bands for an "intentional radiator" as defined in Part 15. From 1.705 MHz to 30 MHz, the field strength limit is 30 μv/m at a distance of 30 meters. On the 80 meter band, for example, this would be roughly the equivalent of an S9+15 dB signal with a 2.15 dBi gain receive antenna (free space dipole) placed at 30 meters.
As I mentioned earlier, all "white goods" of which the subject of this thread is classified, that use digital devices are generally excluded from Part 15 emission limitations. With the proliferation of VFDs, etc. this is an unfortunate exemption for the ham radio community. Some white goods, such as inductive cooking stoves and microwave ovens, are subject to Part 18 regulations.
It is also noteworthy that despite the general white goods exemption from emission limits, it does not mean that they are allowed to cause harmful interference. However, this generally shifts the burden of proof to the amateur and requires that the FCC gets involved. If the ham is the owner of the device, it is
fait accompli.
- Glenn W9IQ