In case you haven’t heard the news today, the much anticpated shutdown of analog TV transmission may be pushed back. Evidence of the inability of the FCC to produce and distribute the redemption coupons for digital receivers may push back the start date by four months. There are some reports that the money to pay coupon holders $40 each has run out. The coupons were available via the FCC website but were limited to two for each household. The coupons had to be used within 90 days to purchase a digital receiver.
In some ways this was good news to me as the planned date of the shutdown was Feb 17, the same as robot ship day.
We made the switch a few months ago. My dad somehow managed to get some friends to give him their coupons, so he tested quite a few brands of converters (maybe he can comment on which worked best). We now have around 10 channels (used to be three), picture is great (I guess there’s a reason for the switch), and we no longer have to turn off the wireless broadband receiver to watch PBS. On the downside, there still isn’t anything good to watch (besides Nova and a few other public broadcasting goodies).
Those extra coupons came from Steve, at his Tucson address (he’s in college), he and his roommates are using the other two boxes there.
I like the Insigina (Zenith) converter box, the RCA is not bad either. The deciding factor is, of course, the features on the remote control!
DTV does seem to be something that is an improvement, even though it’s a hassle. We get all those digital channels very well from 50-75 miles away, with a $30 UHF antenna stuck on the side of the house.
For digital TV, the received signal is binary 
. By that horrible pun, I mean it has basically two states: All (great picture quality) or nothing (not even a snowy picture). The drop off between the 2 is a sharp one so range is a major factor and the signals propagate differently. This is something they learned in the Wilmington, NC test as some people completely lost NBC. The FCC has approved Distributed Transmission Systems (DTS) to hopefully fix the holes, but that too will take time. (I am not saying that is the reason for the potential delay Al is talking about)
Sometimes the signal is poor enough to get bad reception, and it’s mostly unwatchable…unlike analog, which just gets snowy, digital TV gets all ripped up
In the business this is called cliff efffect. The effect occurs at a signal to noise ratio of 15dB. You get picture with 15.2dB and no picture at 15. Propogation is the same as analog since it is an analog signal (digitally modulated) that is transmitted. However, reflections (ghosting) cause considerable problems in the receivers. Since most digital channels were assigned in the UHF spectrum, line of sight communications is the generally the only acceptable way to receive DTV. Those living behind a hill or mountain that were able to receive analog transmissions with snow and ghosts will not receive DTV.
Since the signal is essentially a packetized MPEG format, loss of signal results in blocky video and loud distortion in audio. Many, if not most, stations are broadcasting multi channel signals consisting of one high def (720P or higher) program and one or more standard def programs within the same channel. My station is broadcasting one 720P, one standard def and two less than standard def program streams.