OTA, analog cutoff, UHF to VHF

Discussion in 'TiVo Series3 HDTV DVRs' started by ToddNeedsTiVo, Oct 11, 2007.

  1. ToddNeedsTiVo

    ToddNeedsTiVo Shampoo is not toxic

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    Sep 1, 2003
    Ankeny, IA
    As I understand it, nearly all digital OTA stations are broadcasting at temporary frequencies in the UHF band. Many of us have nice little UHF antennas to pick up these channels to enjoy HD programming.

    When analog broadcasting goes dark in 2009, many stations will move their digital broadcast back down to their formerly analog VHF frequency, right? Much of the UHF band will be allocated to other uses at that time, if I recall correctly.

    Is there a reliable way to predict in advance how well our antennas will do when digital signals become the norm on VHF? The main part of my antenna, which sits on my mantle, is for UHF, but it does have two telescoping rabbit ear elements which I assume are VHF, but I have no current use for them between cable and the OTA digital. I have briefly played with it and my television's analog tuner and the VHF stuff doesn't come in so well. Perhaps digital broadcasts on these frequencies will behave much differently than the analog ones do now.

    Is this all going to be an enormous pain when digital broadcasts move, or do I have this all wrong?
     
  2. bicker

    bicker bUU

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  3. Pab Sungenis

    Pab Sungenis Member

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    Vineland, NJ
    In Philadelphia, only WPVI-DT is moving down to its old VHF channel: channel 6. The other former VHF outside the core band (WCAU-TV) cut a deal with WYBE to switch to channel 35 when the big switch is thrown.

    I think fewer than 100 stations are going back to VHF, and only a handful to low VHF, if I remember correctly.
     
  4. ToddNeedsTiVo

    ToddNeedsTiVo Shampoo is not toxic

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    Sep 1, 2003
    Ankeny, IA
    Interesting. I see that 52-69 are the channels being reallocated.

    I did some Googling and came up with a spreadsheet produced by the FCC. It's found here under the 8/6/07 - FCC Announces Final Assignment of Digital Television Channels - Appendix B entry. While this list probably isn't going to be the set in stone final version (the press release provided there mentions 13 stations seeking a change), it sounds like it is very nearly so.

    I'm not considering where they are currently temporarily transmitting digitally prior to the Big Switch. I'm just comparing their band for legacy analog vs. what band they'll be in for digital after analog goes dark.

    First, I took out the U.S. territories I found at the end, leaving just the states. That left 1,768 stations.

    I then broke it down as follows:

    VHF before, VHF after: 414 (23%)
    VHF before, UHF after: 322 (18%)
    UHF before, VHF after: 66 (4%)
    UHF before, UHF after: 966 (55%)

    Or,
    VHF before: 736 (42%)
    UHF before: 1032 (58%)

    and
    VHF after: 480 (27%)
    UHF after: 1288 (73%)

    27% of the stations will apparently be VHF after the switch (including a handful who were UHF originally), so I guess there will be a significant number of people who will need VHF-capable antenna equipment. That might kind of sneak up on people who get the UHF temporary stuff just fine.

    Here in central Iowa, ABC, CBS, NBC, and PBS will apparently go digital in their legacy VHF channels after the switch. The Fox station, 17, will actually switch one channel to 16 and remain in UHF. Again, I'm not talking about where they currently broadcast digital; that's all UHF for now.

    I hope the rabbit ears portion of my antenna gets the job done on all that VHF! The goofy medieval weapon :D part of it won't be too busy in Feb. 2009 except for Fox.

    Looks like Boston's channel 7 will remain VHF, while 2, 4, & 5 will end up on UHF. (I'm just skimming the spreadsheet there, and I don't know if those are the Big 4 for the Boston area.)
     
  5. bicker

    bicker bUU

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    Nov 9, 2003
    Florida
    I think you need to re-do your analysis because VHF is actually divided into two: Low (VHF 2-6) and High (VHF 7-13). Many (most?) UHF antennas work fine for VHF High.

    Your Boston example demonstrates the impact of this: None of Boston's stations will return to VHF Low, so any decent UHF antenna should work fine.
     
  6. ToddNeedsTiVo

    ToddNeedsTiVo Shampoo is not toxic

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    Sep 1, 2003
    Ankeny, IA
    I'm aware of the gap between channels 6 and 7. I'm reminded of those AM/FM radios that also did TV sound, and one always had to choose VHF high or low because of the discontiguous frequencies. I hadn't considered that VHF low was being nearly abandoned after the 2009 switch until your post prompted me to look at the spreadsheet again.

    There are 1,741 analog stations listed, but 1,768 digital assignments listed. I assume these 27 stations are new enough to have never bothered establishing an analog presence and are transmitting on their temporary digital channel like everyone else, but will be moving to (or staying at) a permanent digital channel.

    So, currently in legacy analog:

    297 (17%) VHF low
    412 (24%) VHF high
    1,032 (59%) UHF
    -------
    1,741


    After they pull the plug on analog and move to their new digital channels:

    37 (2%) VHF low (including my local ABC affiliate, returning to their legacy channel 5) :(
    443 (25%) VHF high
    1,288 (73%) UHF
    -------
    1,768


    Sounds like the digital broadcast/reception/antenna/transmitter power properties of VHF low are nasty indeed for most stations, compared to analog, because those in that band now are rarely coming back. There are, however, 8 stations moving to VHF low that are not there in analog.
     
  7. bicker

    bicker bUU

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    Florida
    As a matter of fact, one of the three main reasons accepted for appeals to channel assignments was assignment to VHF low. (In other words, if a channel complained about being assigned to VHF low after February 2009, the FCC was inclined to switch them to another frequency for that reason only.)
     
  8. renkablue

    renkablue New Member

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    Sep 16, 2007
    I don't know how my post interrelates to your post regarding the 2009 FCC change. Is it my understanding that consumers will need to obtain a converter and the government will subsidize that converters cost. This especially for OTA reception. In the meantime - misinformation has consumers scrambling for cable or satellite reception or the purchases of new TV's that have built in tuners for digital channels.
     
  9. bicker

    bicker bUU

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    Nov 9, 2003
    Florida
    Todd's concern is mostly with regard to antenna reception -- certain antennas are best for UHF, others for VHF, and then there are more expensive and uglier antennas which work well for both. However, if all the channels you try to tune in are in the UHF band or the VHF High band, then many "VHF" antennas will work fine. That's really the whole context of what Todd and I have been discussing.

    You're raising a different issue: tuning. Once the signal is received by the antenna, you need to tune in the signal by selecting out that which is on the desired frequency. Many of the newest televisions have digital over-the-air tuners and no converter box will be needed. Most televisions more than several years old do NOT, and so if you choose to use one of those older televisions you will need a converter box to receive over-the-air signals after February 2009. The government will allow you to apply for two $40 coupons (per household) to be applied towards the purchase of converter boxes. There are restrictions: One coupon per converter purchased. The converter box you purchase must be an over-the-air tuner only, not a combined over-the-air-and-cable converter.

    That is the extent of the subsidy you referred to.
     
  10. hefe

    hefe Rebus Philbin

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    Dec 5, 2000
    CO via Chi-town
    I'm thrilled to see that Chicago channel 2 is moving to 12. No VHF-Low in my market! :)
     
  11. ToddNeedsTiVo

    ToddNeedsTiVo Shampoo is not toxic

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    Sep 1, 2003
    Ankeny, IA
    You're right, Bicker. I've been talking about the antenna needs for my current (and only) HDTV after They Throw the Switch, and my amusement with the whole shuffling/channel assignment thing found in that FCC spreadsheet. I use analog cable for most channels, but OTA for digital. (When those few clear QAM channels I get on my cable are duplicates of OTA, I tune the OTA one.)

    However, we have three other sets in the house, two of which are so old they only have RF coax inputs. One's the bedroom tv on which we watch little more than the news before bed, and another dates back to its use as my (gasp) Commodore 64 monitor and gets turned on a couple times a month (no, I don't still have the Commodore!). But, they still work adequately with analog cable or rabbit ears.

    The third set is a couple years old, but its small size was exempt from the ATSC tuner requirements I state below. But at least I could use its component inputs in the future without having to use a lowly RF converter to go from ATSC to "channel 3/channel 4."

    The minimal use of these last two sets would probably never warrant the additional monthly expense their own (cable or satellite) set-top box. It sounds like many could get vouchers toward OTA tuners for them, so there is hassle and expense with that...and they would need a set of rabbit ears.

    Eventually, cable will dump analog signals, too. That's when these semi-retired sets that everyone has in their spare bedroom or basement junk room will really suffer.

    I found this in the Wiki's ATSC tuner article:

    * By July 1, 2005 all televisions with screen sizes over 36" must include a built-in ATSC DTV tuner

    * By March 1, 2006 all televisions with screen sizes over 25" must include a built-in ATSC DTV tuner

    * By March 1, 2007 all televisions regardless of screen size, and all interface devices which include a tuner (VCR, DVD player/recorder, DVR) must include a built-in ATSC DTV tuner.​

    So, at least the folks out there that don't know an HDTV from a hole in the ground will be finding it harder and harder to buy a new set without an ATSC tuner. But those legacy sets...
     

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