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post #151 of 256 Old 06-09-2008, 10:08 AM
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If that is the case, can you do a full rescan and then manually add the missing channels? Could there be a station broadcasting a virtual channel that is used by a different station at the same time?
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post #152 of 256 Old 06-09-2008, 10:44 AM
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Quote:
Originally Posted by pixelation View Post

Could there be a station broadcasting a virtual channel that is used by a different station at the same time?

No, not in the same local broadcast area. Real channel and virtual channel number will always be a unique pair in the same local broadcast area.
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post #153 of 256 Old 06-09-2008, 12:02 PM
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Quote:
Originally Posted by pixelation View Post

Could there be a station broadcasting a virtual channel that is used by a different station at the same time?

No two stations in the same market can share the same virtual channel, but after 2009-02-17 it will be possible (and not that rare) for one station's physical channel to be the same as another station's virtual channel.
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post #154 of 256 Old 06-09-2008, 04:38 PM
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If your TV/Monitor can remember the channel or video input to which it was tuned prior to power cutoff, and return to that channel or video input after power is restored (and assuming that it also can remember that it was on, and come back turned on when power is restored), you can build an add-on to your Tivax STB-T9 that will eliminate the need to keep the TV's remote around just to turn it on and off. With this add-on, changing the box from standby to on, and later back to standby, will also turn on and off the connected TV. As an added benefit, you'll waste less power because the TV will be completely powered down instead of just in standby watching for a signal from its remote.

This project relies on the presence of a switched 12 volt DC supply and ground on two pins of the 6-pin "Smart Antenna" connector. You'll need to connect the project to the Tivax box with a 6-conductor RJ-12 modular cord (e.g. Radio Shack #279-422), and you'll need to modify the RJ-12 plug slightly to get it to fit the jack; this involves lightly filing the right side of the plug's locking tab (tab facing up) until the tab just clears the offset slot on the Tivax connector. If you take your time and do this carefully, the plug will seat all the way in and fit snugly. You must use a 6-conductor cord, not one with only 2 or 4 conductors as is common among RJ-11 telephone cords.

Pin 1 (the rightmost pin) is ground and pin 2 (the next pin to the left) is the switched 12V. The project otherwise requires only a relay (Radio Shack #275-248 or similar - I chose this one because it can handle 10A@120VAC while only requiring 30ma. from the Tivax unit, which it seems to have no trouble supplying), a standard 2-prong AC power plug, a standard 2-prong AC power socket, wire and solder to put it all together, and some way to safely house the project.

Connect the wire from pin 1 of the modified RJ-12 plug to one of the relay's "coil" contacts, and the wire from pin 2 of the modified RJ-12 plug to the other of the relay's "coil" contacts. Connect the neutral (wider) AC plug blade directly to the neutral (wider) AC socket blade. Connect the hot (narrower) AC plug blade to the relay's normally open (NO) contact. Connect the hot (narrower) AC socket blade to the relay's common (COM) contact. You're done. Plug the modified RJ-12 plug into the Tivax "Smart Antenna" connector. Plug your TV/Monitor into the AC power socket, and plug the AC power plug into the wall. When you turn on the Tivax box, the 12V power actuates the relay and switches on your TV; when you turn off the Tivax box (put it in standby), several seconds later the 12V power disappears, the relay opens, and the TV turns off.

The challange, should you choose to attempt this, is to build this neatly and safely. Recall that you are fooling around with AC line voltage (120VAC) that could injure or kill someone or start a fire if this project is constructed sloppily; and that the 12 volt control voltage from the Tivax box must not be short circuited nor ever allowed to contact the high voltage portions of this circuit. Also beware that if you plan to use the plugs on both ends of the 6-conductor modular cord, these are sometimes wired in a criss-cross fashion such that pins 1 and 2 on one plug end up on pins 6 and 5 at the plug on the other end of the cord; always ring out or trace the cable to see where Tivax-end pins 1 and 2 end up at the project end of the wire, preferrably using a meter to check for the switched DC voltage.

Because I hate fooling around with AC cords and outlets, I built mine into a defunct X10 appliance module, retaining only the built-in plug and outlet (both of which are very sturdy and well-made), snipping out all the remaining parts on the circuit board, then gluing the relay upside down on the board near where the X10 relay was removed. The resulting unit is shown in the attached photo (were it not for the RJ-12 jack on the side, it would look just like it originally did.) Obviously there are many other ways to approach this, the simplest being basically an extension cord with a plastic box (containing the relay) in the middle and the control cable also emerging from that box.

Good luck and happy soldering

UPDATE 6/25/2008 - See post #216 ( http://www.avsforum.com/avs-vb/showt...6#post14160716 ) for a potential simplification (untested, but based on the Tivax schematic) to interfacing with the Smart Antenna connector.

UPDATE 7/1/2008 - Also see post #216 for a recommendation to add a protective diode to the relay coil circuit.

LL
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post #155 of 256 Old 06-09-2008, 05:48 PM
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From one of the earlier post. It seems the Tivax can remember the channel it was on but cannot remember whether it was in standby or not. So after a power outage, it seems the TV will be turned on and remains that way.

IMHO, if you are willing to get an X10 power supply. You might as well attach both the Tivax and TV to the X10 p/s and use a X10 remote to power both of them up.
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post #156 of 256 Old 06-09-2008, 06:33 PM
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Quote:
Originally Posted by frank70 View Post

Just to clarify how EPG works: There are 2 possibilities, PSIP and TVGOS.

All the current boxes that implement EPG use PSIP, in which the future program information is broadcast by the individual stations as part of the PSIP portion of their digital signal (PSIP carries other non-video things like station name, virtual channel, captioning, time, etc.) For these boxes, how much, little, or accurate the info is depends on how much effort the station put into it; some stations have no info at all, or even incorrect info... blame the station.

At least one future box, the Dish/Slingmedia/Echostar TR-40 will receive special digital information from CBS stations called TVGOS (TV Guide On Screen) from Gemstar. This guide provides exactly 8 days worth of info for all stations in your market, the current day plus 7 days into the future. The info is as accurate as it is in the printed TV Guide, for what that's worth. The TVGOS more closely resembles a cable company or TIVO guide - i.e. it is a grid. Other boxes that are reporting support for a 7/8 day EPG probably also license the Gemstar TVGOS capability.

As you may know by now, this info on the DTVPal is not current...i.e., it does use PSIP, so it depends on the individual stations' side data, like most other boxes. It remains to be seen how far in the future the DTVPal will acquire data, i.e., the original version - the TR-40 - advertised up to 7 days (which is part of the reason that many of us thought it would use the TV Guide system) but the newly advertised specs on the DTVPal don't mention any time period...

OTA only. For signal strength at your location: FCC DTV reception map
TVGOS data: Sony 250 from 5.1?, LG3410a from my DTVPal setup here, not any more.

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post #157 of 256 Old 06-09-2008, 07:13 PM
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Quote:
Originally Posted by pixelation View Post

IMHO, if you are willing to get an X10 power supply. You might as well attach both the Tivax and TV to the X10 p/s and use a X10 remote to power both of them up.

That would still require 2 remotes, one to turn on/off, and one for everything else - no net advantage (even in power consumption, since an X10 module itself uses standby power.) The X10 module I used the case of was otherwise dead and useless, which is why I gutted it.
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post #158 of 256 Old 06-09-2008, 07:29 PM
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Quote:
Originally Posted by pixelation View Post

From one of the earlier post. It seems the Tivax can remember the channel it was on but cannot remember whether it was in standby or not. So after a power outage, it seems the TV will be turned on and remains that way.

Not quite - all CECBs are required by default to go into standby after 4 hours, so after a power outage, the box (and the set, if controlled by the box) will come on for 4 hours and then turn off. It would have made more sense if they had designed the STB-T9 to remember whether it was in standby or not, and return to that same mode after a power failure... but they did not, so the 4 hour limit is its salvation. If you disable the 4 hour limit (which you might do if the box is connected to a VCR, DVR, or DVD recorder), you sacrifice this energy saving feature, but you can still leave the TV turned off in this case.
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post #159 of 256 Old 06-10-2008, 12:46 AM
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The Memorex MVCB1000 with analog pass-through clone of the Tivax STB-T9 may now be available at your local Rite Aid Drug Store for $59.99. I just got this ad today in a Rite Aid circular enclosed with my local newspaper showing the Memorex box.


LL
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post #160 of 256 Old 06-10-2008, 05:19 AM
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Quote:
Originally Posted by frank70 View Post

That would still require 2 remotes, one to turn on/off, and one for everything else - no net advantage (even in power consumption, since an X10 module itself uses standby power.) The X10 module I used the case of was otherwise dead and useless, which is why I gutted it.

Actually, the X10 module is just used for the case. There is no power used in the relay when powered down. You are only using .4 watts more for the relay when the unit is on. With really old TV's, mechanical on / off and tuners, this project would make the TV turn on and off with the Tivax. Notice this would work with most units with smart antenna's on them. This would also work well for TV's that remembered their last power state when power is returned.
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post #161 of 256 Old 06-10-2008, 01:40 PM
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I don't think this was discussed before. It appears that the captions output from the Tivax is very poor. At least on a CRT 408i set.

Unlike its menu which has very solid font, even the largest caption font appears hard to read. I don't know what caused it but I would think that it has something to do with interlacing. It appears the caption is not properly de-interlaced by my Sony TV and I see a flickering caption at all times.
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post #162 of 256 Old 06-10-2008, 03:25 PM
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Quote:
Originally Posted by pixelation View Post

I don't think this was discussed before. It appears that the captions output from the Tivax is very poor. At least on a CRT 408i set.

Unlike its menu which has very solid font, even the largest caption font appears hard to read. I don't know what caused it but I would think that it has something to do with interlacing. It appears the caption is not properly de-interlaced by my Sony TV and I see a flickering caption at all times.

I agree the fonts are bad, but if your Sony TV provides closed captions, don't even bother with the Tivax captions, turn them off and turn on the TV's closed captions. All CECBs are required to pass along digital captions to the NTSC output in analog form (i.e. as VBI data.) The only reason to EVER use the Tivax captions is when connected to either an old TV set or an inexpensive TV set, neither of which is likely to have its own closed caption capability.
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post #163 of 256 Old 06-10-2008, 04:48 PM
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Is it required that CECB convert digital captions into analog? I thought it was just the program also comes with analog caption? I kind of like the ability to have captions in translucent background. Hate it see it disabled.
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post #164 of 256 Old 06-10-2008, 08:51 PM
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Originally Posted by pixelation View Post

Is it required that CECB convert digital captions into analog? I thought it was just the program also comes with analog caption? I kind of like the ability to have captions in translucent background. Hate it see it disabled.

Closed Captioning: A converter box is required to pass all closed captioning information included in the digital signal through to the analog TV for decoding by the TVs built-in decoder. Some CECBs also have an internal digital CC decoder, which allows for changes in font and text size.

check the thread in this forum

Evaluating Digital to Analog Converter Boxes for Users of Captioning
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post #165 of 256 Old 06-10-2008, 09:59 PM
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Originally Posted by holl_ands View Post

EIA/CEA-909 interface was designed to SEARCH up to 16 compass headings.
I doubt any of the Smart Antenna implementations would be able to "re-search"
directions while you are watching something without causing significant interruptions.

The EIA/CEA-909 standard is pretty limited, even clunky, at least the first version. But it allows the antenna to be smarter than the protocol.

It sends 14 bits to the antenna:
The last 7 bits are channel number
The first 2 or 4 bits can be used for direction
The 5th bit can be used for polarization
The 6th and 7th bits can be used for gain setting.
However, the use of the first 7 bits is flexible. You could use them for 128 different directions. These bits can also be used to select different fixed direction antennas. The receiver is supposed to have two modes:
one that lets you manually enter the code to be sent and one that automatically tries all 128 permutations and picks the one with the best signal strength/quality.

For mechanical rotators (or more sophisticated devices), the idea seems to be that you connect the smart antenna interface to the rotor control box which also has manual controls. You can then manually set the direction for each channel and since the smart antenna interface tells it which channel the TV is tuned to, it can remember the direction that was last used or explicitly set for that channel. Also, since it knows the frequency, it can hunt for, or track, the best signal on that frequency while you are receiving if it wants to using a duplicate tuner. A mechanical rotor would only be able to find a new peak near the current peak. It wouldn't be able to detect that the best signal is 90 degrees away from the old direction and involves a bounce of a moving van without risking dropping the signal too low.

An expensive active antenna could synthesize two directional outputs and send one to the TV while doing full sweeps on the second one using its own tuner and the smart antenna interface provided physical channel number (2-69).

There is some provision for the TV and the antenna to negotiate a more sophisticated protocol but that would require the TV to have a more intimate knowledge of the class of antenna used in order to know what to send using the new protocol, which is probably why the GE antenna only works with the GE box. In general, I would expect sophisticated devices to simply ignore anything the TV tells it to do and simply take advantage of the fact that the TV tells the antenna what the TV is doing.

Talking to an indoor antenna controller and not directly to an outdoor antenna has another advantage: the smart antenna interface was designed without the slightest consideration for lightning.

So far, however, smart antennas are only slightly less mythological than unicorns. There are only a few on the market and no rotor controllers or antenna switches with smart antenna interface that I can see.
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post #166 of 256 Old 06-10-2008, 10:12 PM
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Quote:
Originally Posted by dagger666 View Post

jeez did you guys take apart your children like this when they were born. it a decoder box, no secert micro film in side....

How would you know, unless you took it apart? The box is loaded with secrets. Stuff that should have been documented. Companies don't realize that when they withhold technical documentation they hurt their customers more than their competitors. Compared to the other CECBs, this box is unusual in that the schematics are available from the FCC.

Most gadgets that come in are subjected to a ritual known as "voiding the warranty".

As for the children, if I had one of those I would just do a CAT scan. And yes, I have the data from my CAT scan here on my computer.
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post #167 of 256 Old 06-10-2008, 11:25 PM
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[quote=pixelation;13799339][quote=jimboy;13783382]
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Originally Posted by satpro View Post


Even if the Tivax have separate zoom settings for HD and SD broadcast. Your mom still won't be happy because the Zoom function may work for one program but not the other. Not all programs are broadcasted in letter box. Your mom will have to use the zoom button eventually.

Some movies even switch formats during the show, like switching between full and letterbox.

To some extent, the box can be programmed to autodetect this. The box knows what resolution is being broadcast. If there is brightness in the center portion of the screen (i.e. not in a fade to black), the box can measure the size of the black borders. It can also compare those measurements to standard broadcast configurations and check for symetry, and do time averaging to deal with odd frames. Some things like a channel bug in the lower right corner of a 16:9 frame containing a 4:3 picture would confuse things but this could optionally be programmed around. But the box could be configured to autozoom after a few seconds to fill the screen with the maximum amount of usable image without cutting anything off. There would be an annoying jump or gradual zoom. Some content would be tricky, like a movie that has a closeup of a screen with everything totally black around it or an illuminated ball bouncing around the screen. A clear edge between black bar and content on all four sides is a pretty good indication that you don't have weird content, though a computer screen image where border fades in (room lights turned on) would be an exception. You could also have an asymmetric window detector that rapidly enlarged the "used" window when their was content outside and slowly shrank it when there was unused area. Would probably work well most of the time and you hit the zoom button when it doesn't. Might be a little sluggish restoring frame after a commercial. Some people would like it some wouldn't. Kinda like automatic transmissions.

If programs are broadcast in their native aspect ratios it is much easier.
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post #168 of 256 Old 06-11-2008, 03:24 AM
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Originally Posted by NIVO View Post

A question here as well(you might even classify it as a hypothetical question). All CECB boxes start out as full featured chips right? Then they are "dumbed down" to meet FCC rules on CECB boxes? Is this correct?

Not really. Many, perhaps most, are based on chips that were apparently designed more or less for CECB and/or standard definition TV applications. It is hard to tell since it is hard to get data on the chips. These chips themselves may be somewhat dumbed down versions of other chips made by the manufacturer with some enhancements. The manufacturer often appears to provide a reference implementation of the software (and also the hardware) that at least illustrates basic operation of all features but may provide a limited user interface as their focus is on making a working chip. The idea may be that the manufacturer is supposed to customize and extend or even replace this user interface. Some vendors, however, may simply replace the name and logo and ship it.

The zoran Super741 chips used in the Tivax are supplied with reference software and hardware (the hardware design, however, is not merely duplicated). This includes 32MB of RAM, the leftover portion of which might store a week of program guide data (and might be intended for such). But if the reference software just had a now/next EPG, guess what you are likely to get?

The reference hardware may include extra stuff to simplify development and high quality parts to show off the chip and isn't really designed for mass production or packaging and is made in low volume at a high price per board. The box manufacturer may take that design and have a junior engineer or even a good technician half copy it, half mutilate it, leaving off what they can and replacing circuits with cheaper parts. The RS-232 port on the Tivax and similar models is probably vestigial, in that it was on the development board and may have been included on the new board design for in house testing of the prototype and then wasn't left off on the production units. It doesn't really appear that they intend to use it for field software upgrades (though they may be hedging their bets against bugs but many users won't have a computer). For in house board testing, software download, repair, etc. they could just use JTAG though the serial monitor may help for some tests. It looks like the person who redesigned the board just focused on one circuit at a time and didn't think about sharing components between circuits with results that can be comical in places.

One big difference between the chips used for CECBs and for high end tuners is the ability to output more than 480i. This lets a lot of shortcuts be taken. The chip used on the tivax supports component output and S-video but there are no connectors and amplifiers for this on the board. It doesn't support DVI. If the chip had been a QFP and not a BGA, it might have been possible to kludge together a component output but unused BGA pins tend to be buried under the chip where you can't get to them.

Tivax vs reference hardware differences:
- fewer buttons
- no SVGA
- no component/RGB output
- no ATSC baseband input
- combined tuner/modulator
They made one critical mistake and that was not putting in pads and 4 traces for an s-video connector (the amp is already there). This was probably due to confusion about whether the government allowed s-video. Then they would have been able to swap in a DTT76852 tuner module (the connected the passthru control line) or possibly an LG TDVG-H151G and an s-video connector and had a box that had all three major I/O characteristics (s-video, passtrhu, and smart antenna) in the feature matrices.
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post #169 of 256 Old 06-11-2008, 06:06 AM
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[quote=whitis;14058822][quote=pixelation;13799339]
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Originally Posted by jimboy View Post


Some movies even switch formats during the show, like switching between full and letterbox.

To some extent, the box can be programmed to autodetect this. The box knows what resolution is being broadcast. If there is brightness in the center portion of the screen (i.e. not in a fade to black), the box can measure the size of the black borders. It can also compare those measurements to standard broadcast configurations and check for symetry, and do time averaging to deal with odd frames. Some things like a channel bug in the lower right corner of a 16:9 frame containing a 4:3 picture would confuse things but this could optionally be programmed around. But the box could be configured to autozoom after a few seconds to fill the screen with the maximum amount of usable image without cutting anything off. There would be an annoying jump or gradual zoom. Some content would be tricky, like a movie that has a closeup of a screen with everything totally black around it or an illuminated ball bouncing around the screen. A clear edge between black bar and content on all four sides is a pretty good indication that you don't have weird content, though a computer screen image where border fades in (room lights turned on) would be an exception. You could also have an asymmetric window detector that rapidly enlarged the "used" window when their was content outside and slowly shrank it when there was unused area. Would probably work well most of the time and you hit the zoom button when it doesn't. Might be a little sluggish restoring frame after a commercial. Some people would like it some wouldn't. Kinda like automatic transmissions.

If programs are broadcast in their native aspect ratios it is much easier.

That's a nice science project.

Instead, just use the Active Format Description system, where content is tagged with its aspect ratio and other data. The system is described in the SMPTE 2016 family of standards.
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post #170 of 256 Old 06-11-2008, 06:36 AM
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Quote:
Originally Posted by whitis View Post

So far, however, smart antennas are only slightly less mythological than unicorns.

Well said!
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post #171 of 256 Old 06-11-2008, 10:39 AM
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[quote=whitis;14058822][quote=pixelation;13799339]
Quote:
Originally Posted by jimboy View Post


Some movies even switch formats during the show, like switching between full and letterbox.

To some extent, the box can be programmed to autodetect this. The box knows what resolution is being broadcast. If there is brightness in the center portion of the screen (i.e. not in a fade to black), the box can measure the size of the black borders. It can also compare those measurements to standard broadcast configurations and check for symetry, and do time averaging to deal with odd frames. Some things like a channel bug in the lower right corner of a 16:9 frame containing a 4:3 picture would confuse things but this could optionally be programmed around. But the box could be configured to autozoom after a few seconds to fill the screen with the maximum amount of usable image without cutting anything off. There would be an annoying jump or gradual zoom. Some content would be tricky, like a movie that has a closeup of a screen with everything totally black around it or an illuminated ball bouncing around the screen. A clear edge between black bar and content on all four sides is a pretty good indication that you don't have weird content, though a computer screen image where border fades in (room lights turned on) would be an exception. You could also have an asymmetric window detector that rapidly enlarged the "used" window when their was content outside and slowly shrank it when there was unused area. Would probably work well most of the time and you hit the zoom button when it doesn't. Might be a little sluggish restoring frame after a commercial. Some people would like it some wouldn't. Kinda like automatic transmissions.

If programs are broadcast in their native aspect ratios it is much easier.

In fact, there is a variable for the Tivax called "BlackBarDetect". Unfortunately, it isn't doing anything.
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post #172 of 256 Old 06-12-2008, 04:25 AM
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Originally Posted by frank70 View Post


1) The aforementioned zoom issue is a little more complicated than previously stated. If "zoom" is selected on an HD subchannel, it does the right thing. If "zoom" is selected on an SD subchannel, it either: a) has no effect at all if the SD mode is 528x480i or 640x480i (which is the desired effect and would be wonderful if not for b), or b) stretches the picture horizontally (off the screen at the ends) but not vertically (a purely nonsensical effect) if the SD mode is 704x480i; SD subchannels in 704x480i seem to far outnumber the others, but here in Philly there are some of both (for example 10.2, WCAU's weather channel, is unmodified by "zoom", as are all the WPPX/ION 61.*).

Not nonsensical, actually. The weird stretched mode is probably anamorphic. It is intended for a 16:9 picture transmitted shrunk horizontally which is how some widescreen stuff works, including in standard def.

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Originally Posted by frank70 View Post

2) On my unit, at least, the NTSC video output leans toward the left at the upper right hand side. Normally, you wouldn't notice this on an SD channel, or on an HD channel showing widescreen content. But on an HD channel showing 4:3 content (or on telecasts with some vertical object or a vertical edge on the right side of the screen) the lean very obvious, as it is when displaying the menu; it's as if the upper NTSC scan lines are shorter and more compressed than the lower ones - some kind of analog distortion. No, it's not my set... I've tried it on several. May be a sample defect, or may be intrinsic to the design.

That sounds like a classic TV problem. Top lines leaning have to do with the phase or frequency of the horizontal oscillator or sync separator issues. If the top left corner is ok but the top right corner is wrong, your horizontal oscillator probably isn't adjusting fast enough to the 180 degree phase shift in horizontal scan caused by interlacing. If you don't see it on other boxes, it may be because they underscan. Or your sync separator is sensitive to very subtle differences between the Tivax sync signal vs. others.

There is one other possible quirk in the Tivax. The schematic looks like there are two alternate amplifiers driving the video out U6 (FMS6143) and Q7 (2N3906). Neither is listed as do not populate so if both are actually populated pulling Q7 would be a good idea. There is also a 220uF capacitor (EC35) in series with the video out line. It is possible that the charge on that capacitor is reduced during the vertical blanking interval affecting the DC offset slightly. Your sync separator should be smart enough to adjust for the DC offset, which should be but some drift could be exciting the bugs in your TV.

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Originally Posted by frank70 View Post

3) One OTA channel in the NJ/Philly area scans in with the wrong subchannel number (WMCN-DT, which PSIPs as 44.1 on any normal DTV, comes up as 44.3 on the Tivax, with no 44.1 or 44.2 at all.) Fortunately, this station shows automobile advertisements all day long, and is virtually worthless anyway.

Maybe the Tivax is looking at the position in the PSIP terrestrial virtual channel table (TVCT) rather than the minor_channel_number stored there and the TV station is formatting the table in an unusual fashion or transmitting some audio only channels.

You may see this bug on other Zoran boxes not made by Shenzhen MTC since this sounds like it could be a bug in the reference software.

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Originally Posted by frank70 View Post

4) After a power failure, the unit DOES remember what channel it was last tuned to. BUT, if it was in the "standby" state prior to the power failure, it comes up in "on" state after power is restored. That is, it can remember the last channel, but not whether it was on or off!

The chip naturally powers on when it gets power. Then it reads the eeprom with the settings. It would then have to intentionally power itself off. Auto power up is actually something which should be configurable: on, off, or last state, but rarely is. Not powering up is probably worse than not powering up since if you have set the autooff timer it will power itself down in 4 hours and if you have disabled autooff you probably want the unit on for something like VCR recording. Thus, in the long run it is following your instructions.

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5) The "standby" and "mute" buttons on the remote are positionally reversed compared to virtually every other (i.e. Japanese) remote. Power is almost always the upper right button on a remote, and if colored, almost always (for whatever reason) green; on the Tivax green-top-right is mute. Bizarre.

Not bizarre at all. I am surprised your remotes are that consistent. There aren't really any documented conventions for this. The Tivax is not a japanese box. I just looked at half a dozen remotes. Many had the power in the upper right, one had the upper left, a universal remote had the power button in the middle below the device buttons, and a TiVo remote had a TV power button in the upper left and the TiVo power in the upper middle. Colors varied.

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Originally Posted by frank70 View Post

6) The overscan in all aspect ratios is excessive, chopping off useful portions of program material, like the tops of heads and scrolling news at the bottom of 4:3 and zoomed 16:9 pictures- much more so than any typical NTSC tuner.

This is something that should be configurable. Absent that, you would expect them to stuff 480 lines of picture data into 480 scan lines.

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Originally Posted by frank70 View Post

7) This unit's tolerance of varying multipath (i.e. trees blowing in the wind) is rather mediocre. I think a lot of folks who buy CECBs are going to be pulling their hair out because of this issue, which is by far the most significant problem with ATSC reception in the suburbs.

So like most Chinese stuff, decently manufactured but poorly engineered and/or tested. My $.02.

[/quote]
Assuming the variation in multipath was consistent when you tested the different converters, the multipath tolerance would be a function of the Zoran SoC/demodulator chip. Finding good chips when you are designing something is very hard. In some markets, such as this, it is even worse because you can't download a real datasheet. The LG chip may be better but LG still doesn't even have a web page for their chips on their miserable web site.

Receiver performance in different locations is going to depend on 1) weak signal sensitivity, 2) static multipath rejection, 3) dynamic multipath rejection, and 4) adjacent channel rejection, 5) strong signal desensitization, 6) noise burst rejection, and 7) co-channel rejection.

NTIA criteria for multipath were for static single echo only.

Where I live, there are lots of big trees.
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post #173 of 256 Old 06-15-2008, 06:51 AM
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Whitis, thanks for all in the info. The Tivax is the only box I have bought so far. It does seem to be well made. The EPG displays 4 lines of program content description (about 25 words), then truncates if the description is longer. Too bad no s-video, or alerts or search in the EPG.
Question: anyone know if the Tivax will work with the GE smart antenna (these are on the shelf at my local Target, while the GE and Venturer boxes are soldout)?
Question 2: what is the link to the schematic for the Tivax?
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Quote:
Originally Posted by Trio View Post

Question: anyone know if the Tivax will work with the GE smart antenna (these are on the shelf at my local Target, while the GE and Venturer boxes are soldout)?
Question 2: what is the link to the schematic for the Tivax?

Somewhere in these CECB threads someone said that the GE Smart
Antenna is marketing hype and not really a "smart antenna" at all.


Dunno.

Myabe check the GE threads?


John
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post #175 of 256 Old 06-15-2008, 02:11 PM
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Thanks Johnied. There is something fishy about the GE antenna. Here are claimed features from a dealer http://www.ezdigitaltv.com/GE_Smart_..._Antenna.html:

"Automatically seeks and locks the strongest DTV signal available
Developed exclusively for use with the GE Smart Digital Converter Box
Uses sonar technology to scan your area to find the best over-the-air DTV signal without any manual adjustments "

Sonar, hmmm. And apparently it is only works with the GE box, so it isn't _that_ smart.

In any case, I don't need one - local antennas are on same hill here, and I can see their lights as I point my Silver Sensor indoor antenna. All stations come in "100%" strength, according to the Tivax. But friends and kin are not in same situation, so I'll keep an eye out for compatible smart antennas to suggest to them if they get a Tivax box.
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Quote:
Originally Posted by Trio View Post

Thanks Johnied. There is something fishy about the GE antenna. Here are claimed features from a dealer http://www.ezdigitaltv.com/GE_Smart_..._Antenna.html:

"Automatically seeks and locks the strongest DTV signal available
Developed exclusively for use with the GE Smart Digital Converter Box
Uses sonar technology to scan your area to find the best over-the-air DTV signal without any manual adjustments "

Sonar, hmmm. And apparently it is only works with the GE box, so it isn't _that_ smart.

In any case, I don't need one - local antennas are on same hill here, and I can see their lights as I point my Silver Sensor indoor antenna. All stations come in "100%" strength, according to the Tivax. But friends and kin are not in same situation, so I'll keep an eye out for compatible smart antennas to suggest to them if they get a Tivax box.


So, you could use a "paper clip" and call it your smart antenna...

All right then. =P

John
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post #177 of 256 Old 06-15-2008, 08:40 PM
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Quote:
Originally Posted by Trio View Post

Whitis, thanks for all in the info. The Tivax is the only box I have bought so far. It does seem to be well made. The EPG displays 4 lines of program content description(about 25 words), then truncates if the description is longer. Too bad no s-video, or alerts or search in the EPG.
Question: anyone know if the Tivax will work with the GE smart antenna (these are on the shelf at my local Target, while the GE and Venturer boxes are soldout)?
Question 2: what is the link to the schematic for the Tivax?

The GE "Smart Antenna" isn't expected to be available until mid Sept:
http://www.jascoproducts.com/hdtv/GE...al-Antenna.asp
"Sonar" analogy is pretty lame....unless you're Tom Clancy, who knows that
Sonar sensor arrays do beam-forming in order to search in multiple directions....
Sorta similar to Smart Antenna beam-forming in order to search in multiple directions....

=========================
The only GE (Digital) Antenna I found on www.target.com is the Quantum:
http://www.target.com/GE-HDTV-Quantu...antenna&page=1
http://www.jascoproducts.com/hdtv/GE...l-Antennas.asp
http://www.jascoproducts.com/product...?idproduct=463
GE specs say it is an amplified antenna..."digital" means DTV compatible...
Target misunderstood "digital" to mean digital signal processor...oops....
No, it isn't compatible with EIA/CEA-909 Smart Antenna Interface Spec....

======================================
DTA-5000 remains the one-and-only available Smart Antenna.
GE (above) said they would have theirs ready by mid-Sept.
Terk said they wouldn't have theirs ready until early next year....

Last month, an RCA DTA-800 with Broadcom Smart Antenna (prototype)
were submitted to Peter Putnam for testing, but due to immediate
problems had to be returned:
http://www.hdtvexpert.com/pages_c/2TV_Converters.html
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Quote:
Originally Posted by whitis View Post

Receiver performance in different locations is going to depend on 1) weak signal sensitivity, 2) static multipath rejection, 3) dynamic multipath rejection, and 4) adjacent channel rejection, 5) strong signal desensitization, 6) noise burst rejection, and 7) co-channel rejection.

NTIA criteria for multipath were for static single echo only.

NTIA CECB test criteria DID include dynamic multipath as part of the
"Field Ensemble" requirements (item #14):
http://www.ntia.doc.gov/ntiahome/frn..._technical.htm

These are ACTUAL SIGNALS captured from fifty of the WORST locations.
Chapter 6 discusses the Field Ensemble test conditions and results for
numerous STBs and HDTVs tested in 2005:
http://www.fcc.gov/oet/info/document...on-testing.pdf
More than half weren't even close to meeting CECB (2007) requirements.

FYI: Here is link to ATSC A/74:
http://www.atsc.org/standards/practices.html
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Talk to Tivax today a new batch of STB-T9 are on the way and all he would say is they have analog pass-through.

Dave
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post #180 of 256 Old 06-19-2008, 11:32 PM
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Now that the newer Tivax's have analog pass through, can someone concentrate on hacking the RS-232 port to do something really useful, like changing channels and turning the unit on and off? By doing so, you could potentially hook it up to a computer and use the computer to act as a timer. (You might even be able to control it remotely with a modem.) That would be good because reviews so far indicate the Tivax gives a better picture than the DTVPal. Also, can Tivax upgrade the old units to include analog pass through?
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