I believe I know exactly which station you worked on Rex, that was probably WTVR 6. That station's been there since 1948! My company did the conversion of all the editing and production equipment. It was sad to see that nice RCA unit get put out to pasture. Clearchannel communications unloaded a bunch of the old RCA transmitters at the radio stations too when they bought them out. THe local talk radio station WRVA also went to a Harris Electric transmitter. IMHO, the Harris A.M. transmitters sound TERRIBLE at the receiving end. They are heavy in midrange, and have a poor signal to noise ratio. to make matters worse, most of the clearchannel stations are pulling their program material off of compressed digital sources, which end up making the high frequencies all gurgley and muddy...just adding to what the Harris transmitter butchers up! Their old RCA had such a nice sound! I remember listening to WRVA back in the 70's on my Dad's Fisher HiFi stereo and not being able to tell the difference between AM and FM! Not so anymore (listening on the same HiFi stereo)
One of the biggest things that people mix up is the difference between digital TV and HDTV. It seems to be happening here a little bit too. Digital TV,or as Martin pointed out, the ATSC broadcast standard is a high bandwidth way of transmitting video information up to 1080i as data to you. HDTV signals can be analogue or digital, although if you want to broadcast a digital signal over a significant distance, the signal will need to be digital.
TV stations had begun the digital and HDTV era editing their HDTV signals in analogue, ususally in "component" (Y, Pb, Pr for all you video techies) This is because most of the equipment came from Japanese makers. The Japanese bad been broadcasting analogue HDTV signals several years prior to the USA. Just before broadcasting, the signal would be converted to an ATSC digital signal before going up the tower. Today, it's all handled digitally. The signal becomes digital at the camera, and all further handling is done in data format. In fact with non-linear editing being the standard these days, the signal rarely ever even sees any moving parts between camera and tower!
One other significant issue that was a problem early on too was the lack of an HDTV camera. Most of the HDTV material that came out prior to about 2001 or so was originally sourced on 16mm film, then transferred an analogue (Betacam SP, M2), or later, digital(digital Betacam, DV-cam, etc), HDTV media with a telecine machine. This was due to the development challenges of a high enough resolution CCD to run live video! (the digital still camera market too!) Early HDTV resolution CCD's needed unusually high amounts of light and were too slow to capture the minimum 30 frames per second (remember, theres a TREMENDOUS amount of data coming off that CCD!)A TV show would be filmed, and then transferred to a video format. It took 2 to 3 times more time to transfer a film to video as it's "real time" speed. For example, a 1 hour television show needed 2 hours to copy to video. This was because the exposure time was only in the 10-15 frame per second rate as the system obtained enough exposure time to capture the image, and then crunch all the information. Once the program was transferred to a video format however, it could be handled on the wide variety of analogue editing and storage equipment that was out there. As processing power increased, and CCD sensitivity did too, and this snafu was solved! The advent of digital video cameras further helped the situation, as it was pretty much impossible to manage HDTV pictures within complex and sensitive analouge camera components.
In your home, you can find HDTV signals in both analogue "Component video" and RGB formats along with digital formats, like DVI, and HDMI. I believe the high-definition VHS decks were actually analogue decks. Due to their complexity, they cost over $2000 when they came out, and were well beyond the budget of most home buyers, so they never caught on. They did however enjoy a brief stint of popularity in the professional market.
