CA Traveler wrote:
With the adoption of HD most major stations switched from VHF analog to UHF (which is also analog transmission) for HD and SD. UHF is line of sight and generally less range. The change was transparent to many unless they were out of UHF coverage or noticed new channels like 7.1, 7.2, 7.3 etc.
But others had to upgrade their antennas or make other changes. Yes there was a lot of SD content last time I checked. But HD has taken over and 4K is pending...
You seem to be confused on your terms. Both HD(High Definition) and SD(Standard Definition) are digital. There are no full power TV stations broadcasting analog. When digital TV started, most stations broadcast both analog and digital simultaneously. This required two transmitters and typically two antennas. For most stations that were broadcasting analog on VHF there was no spectrum available to broadcast the digital on VHF so the only option was to broadcast the digital on UHF. When analog TV was shut down in 2009, some TV stations moved the UHF digital broadcast down to VHF. The main reason for doing this was the huge saving in power usage. Many stations where broadcasting at 1000Kw ERP (Effective Radiated Power) for UHF. They can realize the same coverage using only 50Kw ERP or less once they switched to VHF. This caused a bit of problem for some viewers. Antenna manufactures jumped on the bandwagon and started marketing "Digital Antennas" which were UHF only. Since most digital broadcasts were on UHF prior to the analog shutdown this wasn't much of a problem. When some stations changed to VHF, many viewers could not receive these channels on their "Digital Antennas" because they were UHF.
I am a retired broadcast TV technician and was involved in the installation of much of the equipment required for the transition to digital for the station I worked at.