Thin-Air ATSC (And NTSC): Deciphering Physical Channels And Wrestling With Media Center

Continued from ‘Thin-Air ATSC (And NTSC): Reception Success At Last (At Least For The Present Moment)‘…

Here’s the summary. As I mentioned yesterday, MCE (Media Center Edition) doesn’t actually do a scan for broadcast signals; instead, it downloads EPG (Electronic Program Guide) information for your area after you provide it with your zip code. When the EPG is accurate, the system works great. When it’s not, on the other hand, you end up with problems like mine.

The initial EPG data ends up in a hidden file called atscchannels.xml, located at C:Documents and SettingsAll UsersApplication DataMicrosofteHomeEPGprefs for Windows XP systems and at C:ProgramDataMicrosofteHomeEPGprefs with Windows Vista. A key companion file called atscprefs.xml (which may not yet exist at the beginning of this exercise) contains updates to the EPG-derived information. Both files’ data is cached elsewhere (in locations I don’t know), and if you don’t force MCE to bypass the cache and go back to the data nexus your edits won’t ’stick’, so make sure you exactly mimic the following sequence of steps without doing any manual XML hacking. Trust me, I tried, and it didn’t work

In looking at atscchannels.xls, I discovered that the MCE EPG thinks that KOLO’s digital broadcast is on channel 23. That’s just flat-out wrong; the primary signal is still on channel 9, as I noted before, and the main translator on Mt. Peavine is on channel 49. The station’s Wikipedia entry handily provides a list of its numerous translators; nowhere is there a channel 23 entry. In my particular case, as it turns out, the Pinnacle software tells me that I’m tapping into the channel 24 translator in Verdi-Mogul. No, I still don’t know why I can’t get either KOLO’s channel 9 main transmission on Slide Mountain next to CBS and NBC’s transmitters, or its channel 49 translator next to Fox’s tower, all three of which I receive just fine.

Next, let’s look at KREN. The EPG-provided atscchannels.xls data says that this station’s ATSC beacon is on channel 26, and for Reno residents, that’d be correct. But the Pinnacle utility informs me that I’m tuning in a translator operating on channel 30 (in location unknown). So, for both stations, after closing out of the Media Center Edition program, I deleted their entries in atscchannels.xls. Then, after re-launching Media Center, I manually entered their primary ‘-1′ virtual digital channel details, including the correct corresponding physical channels, all of which ended up in atscprefs.xml. And, after I confirmed that the primary virtual channels now worked, I also added missing secondary virtual channel data both for these and other stations also missing it. Subsequent Channel Guide updates haven’t mucked with this optimized database.

In the process of doing all this tweaking, I also decided to transition away from the HP ExpressCard ATSC adapter to the Pinnacle USB ATSC tuner for full-time use on the Dell XPS M1330. I figure that the Pinnacle unit’s more robust utility suite will come in handy in the future, when further spectrum shifts inevitably occur. And the Pinnacle adapter’s ‘Signal Booster’ feature notably improves my reception signal strength in some cases, thankfully without overdriving already-strong broadcasts in the process. I missed last night’s Lost episode, but it’ll be repeated next week. And I’ve got Ugly Betty queued up to record beginning tonight. Consider me content. Finally.

Followup: I disabled the Pinnacle unit’s ‘Signal Booster’ setting after seeing occasional distortion on some channels indicative of signal overload. I’m seeing occasional dropouts on KNPB and KREN as a result, but the other four (admittedly more important to me) stations (KOLO, KREN, KRXI, and KTVN) are now rock-solid. Pinnacle, can you make ‘Signal Booster’ channel-specific?

Followup II: In watching the Ugly Betty broadcast coming from KOLO last night, I discerned occasional dropouts in it, this after disabling Pinnacle’s ‘Signal Booster’ option (which unfortunately, so says the company, cannot be enabled on a channel-by-channel basis). So if I boost the signal, I get occasional distortion on already-strong channels, and if I don’t boost the signal, I get occasional distortion on not-strong-enough channels. I’m reminded of a bedtime story involving a little girl, three bears and some porridge Hopefully, once KOLO moves its primary beacon from channel 9 to 8, I’ll be able to receive it and won’t have to go through the Verdi translator.