ATSC Tuner - Setup and Operation

Setup and Operation

Most ATSC tuners have relatively simple on-screen menus, and automatically bring the user to a setup screen when turned on for the first time. This allows the user to pick the time zone and daylight-saving time mode (as all stations transmit time in UTC), and bandscan for stations. The scan "listens" on every channel from 2 to 69, and pauses when it detects a digital carrier wave. If it is able to decode the station, it reads its PSIP data, and adds its virtual channels to the channel map. If no PSIP is transmitted, the physical channel number is used, and each transport stream is enumerated according to its TSID (converted from hexadecimal), or starting sequentially at .1, .2, .3, and so forth, depending on the tuner.

Several TV stations are using or have used a temporary channel to send their DTV signals, and upon terminating analog, move their digital transmission either back to their old analog channel, or to a third channel (sometimes the former analog of another local station), chosen in the digital channel election in the U.S. This requires all viewers to re-scan or manually add the new channel and possibly delete the old one. Doing a full re-scan will usually cause other channels to be dropped if they cannot be received at the moment the scan passes their physical channel, so this is typically undesirable, although many ATSC tuners only have this option. Some have an "easy-add" feature which does not delete what is already mapped in memory. Some allow the user to enter the physical channel and an unmapped subchannel, causing the tuner to search the physical channel. Depending on the tuner, this may or may not automatically add the station and its digital subchannels to the map, and/or to the user's "favorites". This may also leave the old "dead" channel mapping in place, so that there is the new 8.1, dead 8.1, new 8.2, dead 8.2, etc. In most cases, TV stations will not have the actual frequency they are currently using on their website.If the auto scan does not pick up the signal and the tuner has manual frequency scan capability try to get the actual frequency from the station engineer. This may allow one to stay on one frequency (channel) versus "scanning" (moving too quickly through) and allow one to make antenna adjustments while observing only a problematic channel.

Other errors which appear to be in the tuner are actually the result of incorrect data sent by one or more stations, often including missing electronic program guide data. Many ATSC tuners will remember EPG info for each station, but only for a few hours after viewing a channel on that station. Some will not remember at all (displaying only the required channel banner), while a very few others will store data for days (although this requires staying tuned to each station for more than a few seconds in order to receive the extended info). DirecTV receivers with ATSC tuners can download the guide at any time, while other TiVo units download guide data separately. TV Guide On Screen can also be used for this, but very few if any ATSC tuners include this (which requires downloading all guide data for all channels from one particular station). Stations sending the wrong time are also a major problem, as this can skew or ruin guide data for all stations until correct time is received again from a different and correctly-set station.