3 ms·
I’m pretty sure they meant AM radio which is around 1.5 MHz and below.
by colejohnson66 7y ago
I’m pretty sure they meant AM radio which is around 1.5 MHz and below.
- jsjohnst 7y agoAM radio stations in the US are from 530Khz to 1700Khz, so possible. If so, then calling them “extremely low frequency” is a bit of a misnomer, as that band is called “medium frequency” or MF for short. The actual ELF band is 3-30hz, 4+ orders of magnitude lower frequency, and is mostly only used for submarine communication as most higher frequency signals are filtered by water.
- SamPatt 7y agoI thought that was obvious, yes. My point is that the basis for the designations were made in a period where AM radio was the primary use case for radio and so frequencies higher than the AM radio band are called "high frequency," whereas today those frequencies are actually much, much lower frequency than nearly all forms of radio communication.
- jsjohnst 7y agoThe name MF/HF/VHF etc were defined by ITU v.431 originally in 1953. Amateur radio operators in the 1950s commonly were using “shortwave” frequencies (now referenced as HF commonly). As it’s been told to me from multiple operators in that era, the naming scheme used by ITU for each group is based on the amount of bandwidth available in each group, not based on any presumption of AM radio broadcasts being used as a baseline.