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Cable Nets Over Air in the 90's?

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  • w9wi
    replied
    There's contact information for the MVTV system here:

    https://www.mvtvwireless.com/contact-us/

    Leave a comment:


  • Trip
    replied
    I want to update RabbitEars to reflect this change but have no way of knowing which transmitter is carrying what. Does anyone know?

    - Trip

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  • w9wi
    replied
    Looks like five of their muxes got repacked: 21=>19, 40=>26, 41=>31, 45=>33, and 49=>36. I think 21 got bumped by KDLT in South Dakota. (which, in turn, was repacked from channel 47)

    I'm thinking they were losing TV subscribers at a pretty good clip. (just like traditional cable providers) Dropping the subscriptions allowed them to stop maintaining the set-top boxes, and to stop having to pay for access to "cable" channels. Best I can tell, nearly all of the channels they're keeping are broadcast, and free for MVTV to relay.

    (I don't know where the 29s are coming from. Except for 10, (which is a local PBS) the rest are all coming from Minneapolis. The station in Minneapolis that used to be analog and virtual 29 is now using virtual 9, but doesn't carry any of those programs.)

    The cost of retuning those five transmitters (and antennas?) probably entered into the equation as well.

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  • Raymie
    replied
    I am bumping this thread to provide some important information on the Granite Falls system. MVTV, the provider, has converted to financing its system by donations as of this month and has turned off the Conditional Access. They are telling their viewers to disconnect their STBs and destroy the CA smart cards. They also no longer feed any cable channels, and very likely have stopped using MPEG-4.

    Compare the new lineup of services:



    to 2017:



    I am not sure why they changed out, especially going away from a subscription service. I suspect they had to change due to repacking? (It doesn't seem they lost any muxes — they still have 12.)
    Last edited by Raymie; 10-07-2018, 12:36 AM.

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  • Guest
    Guest replied
    ION Media in Houston, KPXB, launched a service a couple of years ago called AirBOX. AirBOX does indeed use (encrypted) MPEG-4. Of course, it's running on a full-power station that includes standard ATSC MPEG-2 transmitted in the clear, so we can't really use it to discuss PSIP requirements. RabbitEars had some detail on it a couple of years ago, back when ION was testing it.

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  • w9wi
    replied
    Originally posted by Raymie View Post
    These have to be the only stations in the US using either standard then. There's not a lot of A/72-compatible TV equipment floating around (at least in the US - I know some is in the Mexican market but even then A/53 is the minimum required for TVs, all stations must broadcast at least one channel in MPEG-2, and if you tune an MPEG-4 channel on MPEG-2 equipment you get audio only).
    And that (audio only when tuning an MPEG-4 channel on MPEG-2 equipment) also occasionally happens with satellite feeds...

    My gut feeling is we're going to see more MPEG-4 compatible equipment. MPEG-4 is part of DVB-T2, increasingly used in Europe. A quick look at the chips available suggests the RF tuner, demodulator, and decoder are three separate chips -- so a North American standard design could add MPEG-4 by simply using a decoder chip that supports it -- the RF tuner and 8VSB demodulator would be unchanged.

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  • Raymie
    replied
    Wow, that's an impressive photo. Interesting to see the ONTV logo on it even though the ONTV name was not used in Philadelphia.

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  • NN2E
    replied
    Found the box...

    Pictures_015.jpg


    ... it appears to have a 1982 date-code on the back.

    ...and a little history to go with it...

    http://www.broadcastpioneers.com/bp4/channel57.html

    73, Ed NN2E
    Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

    Leave a comment:


  • Raymie
    replied
    Originally posted by w9wi View Post
    Apparently not. The four ATSC standards specified in the FCC regulations:
    A/52 (AC-3 audio)
    A/53 (the main ATSC standard)
    A/65 (PSIP)
    A/85 (audio level control - "CALM Act")

    [...]

    These are LPTV stations. 73.682, the regulation which lists which ATSC standards must be observed, **does not appear** in the list of full-power regulations that are applied to LPTV stations. The way I read that, any transmission standard that complies with 74.735, .736, .750, .751, and .761 is legal for LPTVs. (remember, I am an engineer, not a lawyer, and could be very wrong!) The way I read those regulations, A/70 and A/72 would in fact be acceptable for use by LPTVs.
    These have to be the only stations in the US using either standard then. There's not a lot of A/72-compatible TV equipment floating around (at least in the US - I know some is in the Mexican market but even then A/53 is the minimum required for TVs, all stations must broadcast at least one channel in MPEG-2, and if you tune an MPEG-4 channel on MPEG-2 equipment you get audio only).

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  • w9wi
    replied
    Originally posted by Raymie View Post
    They are definitely ATSC television services, and if they are using A/70 then they do need PSIP. (Page 25)

    This is the STB they use. It combines reception of normal ATSC signals with A/70 conditional access support. And yes, the box (this is probably the recent box) supports MPEG-4.

    ...Are A/70 and A/72 (MPEG-4) even approved by the FCC for use in the US?
    Apparently not. The four ATSC standards specified in the FCC regulations:
    A/52 (AC-3 audio)
    A/53 (the main ATSC standard)
    A/65 (PSIP)
    A/85 (audio level control - "CALM Act")

    A/54 and A/69 are recommended practices for implementing the rest of ATSC - they aren't part of the rules but are mentioned in the rules.

    That said, the rules for subscription services allow for any scrambling method that meets FCC approval after passing certain technical tests. The rules were written for *analog* scrambling methods but I suspect A/70 would pass the technical tests.

    And...

    These are LPTV stations. 73.682, the regulation which lists which ATSC standards must be observed, **does not appear** in the list of full-power regulations that are applied to LPTV stations. The way I read that, any transmission standard that complies with 74.735, .736, .750, .751, and .761 is legal for LPTVs. (remember, I am an engineer, not a lawyer, and could be very wrong!) The way I read those regulations, A/70 and A/72 would in fact be acceptable for use by LPTVs.

    =====================

    The old analog scrambling system involved mixing the video with a sine wave signal of fixed frequency (I think the same as horizontal sweep) and occasionally varied phase. As noted, it didn't really scramble things very well. Some stations transmitted the audio on a subcarrier (like SCA for FM), others just carried it in the clear. It wasn't particularly difficult to build your own descrambler - and if there were R-rated things going on, you could usually figure it out even if you didn't have a descrambler.

    I'm sure A/70 is a LOT more effective!

    Leave a comment:


  • Raymie
    replied
    Originally posted by egrabow View Post
    So how do DXers ID these translators without decoding equipment? Does PSIP still work or is it necessary to use a tool like TSReader?
    They are definitely ATSC television services, and if they are using A/70 then they do need PSIP. (Page 25)

    This is the STB they use. It combines reception of normal ATSC signals with A/70 conditional access support. And yes, the box (this is probably the recent box) supports MPEG-4.

    ...Are A/70 and A/72 (MPEG-4) even approved by the FCC for use in the US?

    Leave a comment:


  • egrabow
    replied
    Originally posted by toyinduluth View Post
    So how do DXers ID these translators without decoding equipment? Does PSIP still work or is it necessary to use a tool like TSReader?

    Leave a comment:


  • Raymie
    replied
    Also there's a list of channels available.

    Some channels require the "Expanded" STB and I have to wonder if they are using MPEG-4 compression and/or ATSC A/70 encrypted DTV standards.

    These are the multiplexes on the system:

    2.x: KTCA
    10.x: KWCM (this is not part of the system)
    14.x: MVTV Channel, WCCO and five cable channels
    16.x: HSN, KSTP, KARE and its weather subchannel
    21.x: QVC, KSTC, some diginets, Hallmark and ESPN
    22.1: AMGTV (odd that this is the only thing on the 22 multiplex)
    24.x: ShopHQ, Fox Sports North, BTN, Weather Channel
    29.1: BIZ TV
    32.x: TBN but only three services
    40.x: EWTN, CW, GRIT, FX and three Discovery networks
    41.x: NASA TV, KMSP, WFTC, Fox Sports 1
    49.x: Various cable channels.

    It's worth noting that only a couple of stations on each mux are available with the "Basic" box. Only one or two on the 14, 21, 24, 40 and 49 muxes are available in "Basic".

    I'm reminded of what Azteca did with HiTV, a failed service that used the bandwidth of its two (or three) stations in Mexico City, Toluca and Guadalajara to broadcast about 20 channels total and also used MPEG-4. It fell apart because the SCT ruled that they could not broadcast a pay service over a regular broadcast TV concession.

    Leave a comment:


  • Raymie
    replied
    Originally posted by NN2E View Post
    Many years ago (late 70s? early 80s?) Philly had a channel 57 OTA, scrambled, pay service. I believe it was called, "WHT." It used a set-top box descrambler connected to a little UHF Yagi aimed at Philly. I may have one of those boxes buried out in the shed. I see if I can dig it out and take a picture of it.

    73, Ed NN2E
    Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds
    UHF subscription television stations were common (similar type of equipment) in the early 80s in major markets, as some of these areas lacked cable.

    You're thinking of two stations with one stroke: 67 New York ("WHT") and 57 Philadelphia (which broadcast the local premium cable channel PRISM after running SelecTV 1981-83). Chicago at one point had multiple; while 66 "Spectrum" folded up, 44 "ON-TV" lasted into 1985. Boston (27, 68), Detroit (20, 31), Phoenix (15), LA (22, 52), DC/Baltimore (50/54), St. Louis (30), Cleveland (61), Dallas (33 and 27), etc.

    The most common scrambler was SSAVI by Zenith, but that was defeated relatively easily. It was the entrance of cable into these areas and the continuing piracy problems that marked the end for these services.

    Leave a comment:


  • toyinduluth
    Guest replied
    Originally posted by w9wi View Post
    So Granite Falls is indeed still being transmitted on UHF LPTVs. The website indicated they were scrambled but wasn't clear whether they were still transmitted on UHF or on some microwave service.
    its UHF. A tvfool report for GF
    http://www.tvfool.com/?option=com_wr...f1f0b9d8e50ef0

    Leave a comment:

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