A wish list. Function & features we need on DTV tuners - Page 2

My Sharp Aquos tv tuner lists stations saved into memory by their Virtual channel numbers only, with manual entry possible only via Real channel number entry (which does manually add stations to the memorized station listing, but listed by Virtual channel number). It is able to save into memory multiple stations having different Real channel numbers but shared Virtual channel numbers, or overlapping Real and Virtual channel numbers, but only if they are saved into memory in a certain order. It cannot, however, tune two different stations that share Real channel numbers, so it will swap them back and forth with each other in the memorized station listing as they are received, or simply not ever receive the second station. My tuner has single scanning capability (but no additive channel scan that saves all stations from a previous scan).

Using a Channel Master 4228A on a rotor on my chimney (no amp), the overlapping stations I receive include the following categories:

1 – Shared Virtual channel numbers but different Real channel numbers, AND the Real and Virtual channel numbers are different from each other for each station – this is no problem, as tuning these stations manually by their Real channel number will cause my tuner to simply save both stations into memory as two stations listed one after the other under the same Virtual channel number:

WEYI (NBC) Saginaw, MI – Real 30.1 / Virtual 25.1
WVIZ (PBS) Cleveland, OH – Real 26.1 / Virtual 25.1

WNEM (CBS) Bay City, MI – Real 22.1 / Virtual 5.1
WEWS (ABC) Cleveland, OH – Real 15.1 / Virtual 5.1

2 – Shared Virtual channel numbers but different Real channel numbers, but one station’s Real channel number matches its Virtual channel number - my tv will save these into memory under their respective Virtual channel numbers, but ONLY if I enter them in manually by their Real channel number (or cause the first of the two to be auto-scanned in that way) in the order of the station having the SAME Real and Virtual channel numbers entered in FIRST. This will cause my tuner to simply save both stations into memory listed one after the other under the same Virtual channel number. But if I entered them in the reverse order (by first entering in the station whose Real and Virtual channel numbers are DIFFERENT), then attempted subsequent manual entry of the Real channel number for the other station will simply cause the tuner to jump to the Virtual channel number, tuning that same first station again, and never being able to enter or tune in the other station:

WVPX (ION) Akron, OH – Real 23.1 / Virtual 23.1
WUDT (Day) Detroit, MI – Real 8.1 / Virtual 23.1

3 – Overlapping, but crossed, Real and Virtual channel numbers – similar to #2 above, my tv will save these into memory under their respective Virtual channel numbers, but ONLY if I enter them in manually by their Real channel number (or cause the first of the two to be auto-scanned in that way) in the order of the station having the OVERLAPPING Real channel number entered in FIRST, and then the Real channel number of the other station second. This will cause my tuner to simply save both stations into memory listed one after the other under their respective Virtual channel numbers. But if I entered them in the reverse order (by first entering in the NON-OVERLAPPING Real channel number first), then attempted subsequent manual entry of the Real channel number for the other station will simply cause the tuner to jump to the Virtual channel number of the previously-tuned station again, and never being able to enter or tune in the other station:

WEYI (NBC) Saginaw, MI – Real 30.1 / Virtual 25.1
WGTE (PBS) Toledo, OH – Real 29.1 / Virtual 30.1

4 – Shared Real channel numbers but different Virtual channel numbers AND neither station’s Real channel number matches its Virtual channel number – since my tv cannot tune two different stations that share real channel numbers, as I rotate the antenna for these stations, my tv will swap the two stations back and forth with each other in the memorized station listing as they are received (but can never store both stations into memory at the same time):

WDCQ (PBS) Bay City, MI – Real 15.1 / Virtual 19.1
WEWS (ABC) Cleveland, OH – Real 15.1 / Virtual 5.1

5 - Shared Real channel numbers but different Virtual channel numbers AND one of the station’s Real channel number matches its Virtual channel number – since my tv cannot tune two different stations that share real channel numbers, once one of these stations is entered into memory (by any means), and I then rotate the antenna for the second station, manual entry of the same Real channel number again (looking for the second station) often causes my tv to apparently jump to the Virtual channel number of the first station, and continue to search for it (but the antenna is now aimed toward the second station), so I can never receive the second station without completely erasing the entire memorized station listing and starting over. But I have had at least one instance where the tv will add the second station right after the first one in memory (but it doesn't always do this; can't figure out why):

WSMH (FOX) Flint, MI – Real 16.1 / Virtual 66.1
CHWI (CTV2) Wheatley, ON – Real 16.1 / Virtual 16.1

WNEM (CBS) Bay City, MI – Real 22.1 / Virtual 5.1
CIII (Global) Stevenson, ON – Real 22.1 / Virtual 22.1

WCMZ (PBS) Flint, MI – Real 28.1 / Virtual 28.1
WUAB (MyNet) Cleveland, OH – Real 28.1 / Virtual 43.1

I'm surprised you haven't run into a direct swap (e.g. 11 -> 12 and 12 -> 11), or a cycle ( e.g. 11->12 12->13 and 13->11).
It would be interesting to see how the software fails in those situations.

DAP:

I have run into a direct swap, but it's only present on tropo nights when the atmosphere is unusually hot for long-distance reception:

WMYD (MyNet) Detroit, MI - Real 21.1 / Virtual 20.1
WFMJ (NBC) Youngstown, OH - Real 20.1 / Virtual 21.1

I found that in order to receive WFMJ, our local station WMYD cannot already be saved into memory on my tv. As long as WMYD is not already in memory (meaning that it has never been tuned since the last time the tv's memory was cleared), I can simply enter in Real 20.1 on a good tropo night and WFMJ will appear and be automatically saved into memory. After WFMJ is saved into memory, the tv cannot receive the local station WMYD at all since entering Real 20.1 always tunes to WFMJ (because my tv tunes first by Real channel number) and because entering 21.1 has already been exclusively associated by the tuner as the Virtual channel number for WFMJ after being tuned in once previously (which, on my tuner, apparently always overrides the possibility of the tuner considering that 21.1 could be the Real channel number for another station, in this case WMYD).

The failure of the software here is the automatic exclusive association of a Virtual channel number with a Real channel number once a station has been tuned once by the tuner. This forecloses the possibility of the Virtual channel number for a first station also being possibly considered as a Real channel number for a second station. Corrective design could include removing this exclusive association and allowing the multiple entries to be considered by the tuner separately and/or taking into account the station identification (call letters) from the PSIP data to allow listing of multiple station entries having shared or overlapping Real and/or Virtual channel numbers in all possible combinations in the tuner's memorized station listing. I suppose the best tuner design would simply consider the unique combination of Real channel number plus Virtual channel number plus station call letters together for each station to allow separate station tuning and memorization.

Accordingly, I have to enter all stations in manually (using Real channel numbers, and taking into account the required entry order for certain stations) in order to maximize reception. Even then, there are some stations that I simply cannot tune without wiping the tuner's memory clean.

It seems that the right way to do it would be to store a list of channel names with maps to frequency & sub-channel, with the ability to directly specify the frequency to tune for finding new channels. The name would need to be more than just the remapped channel number & sub channel and would need to be an editable string to handle collisions.

MythTV almost does this, but does not support aiming an antenna that I am aware of. It does support multiple tuners so one can have multiple tuners with antennas aimed in different directions with different channel maps.
It is a lot of work to maintain a MythTV setup though.

ANTENNA CONTROL

A lot of people are suggesting multiple tuners for multiple static antennas.

Need to go TVRO route where the OTA DVR controls an antenna rotor system which is tuned for each channel.
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COMPONENT OUTPUT SPECIFICATIONS

Another big deal is knowing Just what is output over the Component Video outputs?

The tendency in BR players to omit Comp since HDMI is present. I believe there are sometimes degradations in Comp when HDMI is also present.
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IEEE-1394 Firewire MPEG-2 TS OUTPUTS

Sorry, this is still quite important to a lot of people.
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DIGITAL AUDIO OUPUTS

Again, HDMI is not the only digital audio output.
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TUNER SENSITIVITY SPECIFICATIONS

I am in a locations where if I don't get the best tuner, I am dead in the water. It is very frustrating to drag home some TV w/ATSC tuner only to find it doesn't bring in my channels. Yes, I have a CM-4228/7777 and that is marginal with a CM-7000 DTV STB.

Exactly. What's being described is way beyond consumer devices.


So would I, but that brings up the next question. What would a device as described cost? My guess is somewhere close to a grand. And once you get there, how many could be sold at that price?

Like the title says. A Wish List.

Most of the hardware to do what I requested is already present in existing tuners, and would only require the developers write software to implement them.

The exception is the wideband power measurement. About $10 in parts using a part like this: http://www.analog.com/en/rfif-compon...s/product.html would be all that is necessary to accomplish it though.

What ATSC tuners need are better manuals that describe good antenna placement.

Last month I helped a neighbor fix her rabbit ears. The signal strength meter didn't help because it showed all the bars, except during those drop outs that happened every couple of minutes when it showed no bars. It was driving her nuts and she can't afford cable.

Not only did she not know which direction the TV towers are from our neighborhood, she didn't know that she needed to know that. Back in the analog days we'd just spin those rabbit ears every which way until we got a decent picture by accident. We didn't know why pointing the ears that way worked because we didn't have to know. You can't do that with digital in some cases.

As you probably guessed, she had them pointed in the worst possible direction. She figured putting them next to a window would be best place which sounds right but wasn't in this case. The signal strength in our neighborhood is so strong that you can point rabbit ears in any direction and get "full strength" on any ATSC tuner most of the time but you can still get drop outs.

Once I pointed them in the right direction (perpendicular to her TV screen and window which she joked, "Looks completely wrong!") she now gets perfect reception.

I was pawing through some old video tapes last night, and I found some excerpts from the DTV "Nightlight" programming, which was produced for one station to run in each DMA after the "Analog Shut-off".

The last segment before we signed off permanently, showed one of the engineers demonstrating the "Digital Cliff", using a Sony TV with both "Signal Quality" and "Signal Strength" meters, simultaneously.
As he lowered the signal level, the "Strength" meter slowly moved down, from about 90% to 10%. But, the "Quality" meter stayed right up around 80% or so, until the "cliff". Then, it dropped abruptly to almost zero....showing that there was a lock on the data stream, but not enough to decode any information.

Probably a great demo and indicative of the "digital cliff". But most TV tuners do not have both a strength and quality meter. Either way... how did/does multipath come into the equation?

I'd suggest one meter measured signal power, the other S/N ratio and it makes sense. Lower the power... the only thing left is noise.

The colored histograms I once viewed on my year-2000 Philips 64PH9905 CRT RPTV, until '09, showed both signal strength and multipath. That was useful in mid-Manhattan where multipath is horrendous. Spaced vertical bars, displayed horizontally, indicated numerous multipath signals; their height varied with signal strength. Channel tuning, from a book-size indoor UHF Silver Sensor antenna atop the RPTV, involved pivoting the antenna, often 20-90 degrees from the broadcast sites (twin towers or Empire State Building), to minimize multipath or maximize strength. Multipath changes often disrupted images/audio. Fortunately OTA was rarely used and cable was available. -- John