[mythtv-users] Indoor HD antenna question

Sat Apr 14 02:15:27 UTC 2018

On Fri, Apr 13, 2018 at 5:43 PM Barry Martin <barry3martin at gmail.com> wrote:

>
> Leo and Ashu:
>
>
> One of the problems with digital TV is too much signal can be as bad as
> too little signal: both conditions will cause the signal to drop out.  With
> borderline conditions (back-and-forth with too much, too little) the tuner
> will pixelate; with too much or too little the screen will turn blue or
> otherwise blank.  With Analog/NTSC the screen went 'snowy'.
>
> This is why sometimes amplified antennae work and sometimes they don't.
> Then there's the length and type of coax, splitters -- and number (2-way is
> 3 dB and 4-way is 6 dB)....
>
> Leo: if the too-much signal is your issue they do make attenuators.  Can
> be the variable type or the fixed (3 dB, 6 dB, etc.) type.  Sort of getting
> into a different issue from Ashu's.
>
> Ashu:
>
> FIrst - my apologies - i was out of town for the whole week and couldn't reply back. So let me start off by saying that when I put the antenna directly in my TV - i get all the OTA channels (except CBS - channel 2)
>
>
> Just to drive ya nutz <g>....   The Good News is _any_ antenna will pick
> up _any_ signal.  Antennae are basically anything that picks up a signal.
> They start differentiating themselves with selectivity.  The old 'rabbit
> ears' antenna was designed to received the old Channel 2 through Channel 13
> VHF TV Band _but_ they will also pick up the UHF band, just not as
> efficiently.
>
> Channel 2 - Chicago is WBBM:
> https://en.wikipedia.org/wiki/WBBM-TV  ...OK, over in sidebar off to the
> right is what I'm talking about:
>
> Channels <https://en.wikipedia.org/wiki/Channel_%28broadcasting%29>
>
> Digital <https://en.wikipedia.org/wiki/Digital_terrestrial_television>:
> 12 (VHF <https://en.wikipedia.org/wiki/Very_high_frequency>)
> Virtual <https://en.wikipedia.org/wiki/Virtual_channel>: 2 (PSIP
> <https://en.wikipedia.org/wiki/Program_and_System_Information_Protocol>)
> Subchannels <https://en.wikipedia.org/wiki/Digital_subchannel>
>
>    - *.1:* 1080i <https://en.wikipedia.org/wiki/1080i> 16:9
>    <https://en.wikipedia.org/wiki/16:9> CBS2-HD
>    - *.2:* 480i <https://en.wikipedia.org/wiki/480i> 4:3
>    <https://en.wikipedia.org/wiki/4:3> Decades
>
> Translators <https://en.wikipedia.org/wiki/Broadcast_relay_station> 26 (
> UHF <https://en.wikipedia.org/wiki/Ultra_high_frequency>) Chicago
> WMEU-CD <https://en.wikipedia.org/wiki/WMEU-CD> 32.3 and 32.4 (UHF)/ 48.3
> and 48.4 (PSIP) Chicago
> (I wonder how that's going to upload: as I write this it was imported as a
> nice chart.)
>
> WBBM says they're "Channel 2" because from the Olde Dayz of NTSC (analog)
> they were Channel 2 -- at the very bottom of the VHF band.  Now with ATSC
> (digital) they're at the top of the VHF band.  WTTW used to be analog at
> Channel 11 so where WBBM is now is one click higher.   The problem in not
> receiving might be because they (WBBM) are in the VHF band.  Most of the
> digital stations moved to the UHF band (Chs 14 to 83 on the old analog
> sets).  [There's a technical error in the digital interpretation of that
> statement -- I'm trying not to confuse you any more than you possibly are.]
>
> Most "digital TV antennas" are designed to receive the UHF band and and
> essentially ignore the VHF band.  This might be why your test connection
> to your TV did not pick up WBBM.  Could also because the antenna was
> pointed in the wrong direction, there's a skyscraper in the way, there's a
> metal support beam in the signal path, etc., etc.  You might be able to get
> around with moving your present antenna, using a coupler to add a rabbit
> ear antenna to your present antenna, or if the coupler creates problems you
> probably need to get a UVSJ like I talked about in a previous message.
>
> OK, back to that chart from  WBBM.  (Actually it's a pretty good example
> of a few other things!)
>
> Subchannels section.  They're all the same main channel, just different.
> I sort of think of it as the SCA signal In FM but most people go 'huh?'.
> Sloppier example but workable would be the left and right channels in FM
> Stereo.  The left channel is Channel 2.1 and the right channel is Channel
> 2.2.  (Oh there are so many things technically wrong!!)
>
> I'm going to go on to the Translators part.  For whatever reason WBBM has
> their main signal at Digital Channel 12 (VHF) but they are also
> transmitting at Digital Channel 26, which is a UHF frequency.  You might be
> able to receive them at RF 26 but not RF 12.
>
> Not trying to confuse the issue but we have a similar translator issue
> here in the Quad Cities.  (Yes, I'm 180 miles west of you: Davenport,
> Bettendorf, Iowa; Rock Island and Moline in Illinois.)  WHBF is Channel 4
> and is transmitting on VHF Channel 4 at the Bettendorf IA antenna farm.
> They have problems getting that signal into Rock Island (which is 'funny'
> because their studios are in Rock Island) and so have a second transmitter
> at Channel (RF) 47.  We don't quite have those billion-story skyscrapers
> <g> but the reception issues have the same effect.
>
> Here at the house I pick up Ch 4 with no problems -- the transmitter is
> about 2 miles away.  I can also usually pick up Ch 47 which transmits about
> 4 miles away (lower power, directional).  The 'fun' part is some TVs will
> see two 4.1's, 4.2, 4.3, and 4.4, some display as 4.1 (etc.) and 47.1
> (etc.), and other TV combine: I have "4.1" but it could be picking up
> 47.1.  (Good news: in the Backend my HVR-1600, HVR-2500 and HVR-950Q kept
> the two separate as 4.x and 47.x.)
>
> Back to WBBM, I'm also seeing where it appears both of WBBM's channels are
> being simulcast on WMEU's 32.3 and 32.4.  I'm not quite sure what station
> 48.3 and 48.4 are -- WMEU might have a translator.
>
>
>
> Somewhere it was stated you have a PVR-150 and other responses said it was
> an analog tuner.  Won't work because it doesn't know what to do with
> digital signals.  Hauppauge's HVR-950Q is a pretty good digital tuner.  I'd
> probably pick up a few, plug them into a powered USB hub, and plug the hub
> into a rear panel port.
>
> I mention I'm using HVR-1600 and HVR-2500.  The 1600 is PCI and has a
> single tuner.  The 2250 is PCIe and has dual tuners (two tuners in one
> board).  I don't recall what available slots are on your motherboard.  I'm
> not sure if these would be a good option: they were really good when I
> purchased but that was years ago.  Tuner sensitivities have improved since
> then.  Go with the advice of the others.
>
> Barry
>
>
>
Thank you. I am getting the point as I read through this all. My problem at
this point however is that on myth I am unable to get ANY channels! I am
trying to fix that driver issue for now...
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mythtv.org/pipermail/mythtv-users/attachments/20180414/412b7855/attachment.html>