Digital Dialog

Digital Dialog - A PBS Hawaii Engineering Blog

Steve Komori guides PBS Hawaii through its transition from analog to digital television, he looks to use DIGITAL DIALOG as a place to share his insights into the challenges and solutions he encounters.

Please direct e-mail communications regarding DIGITAL DIALOG to: skomori@pbshawaii.org

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DTV Reception Refresher

Now that the DTV transition is a year old, the largest complaint is usually the reception of the signal.  I have explained it all in prior blog entries, but it isn't easy to access...so here is a great URL that summarizes everything I have said and some things I haven't:

http://www.dtvanswers.com or http://antennaweb.org

There are many more websites available, but this one seems to answer most reception by antenna problems, except the interference issues, which can come from anywhere (especially within the house itself), such as motors (using a fan?), or electronic devices (using a computer?)...But start with the suggestions in the above website and move on from their if you still can't receive the signal you want.

Unfortunately for others, if you cannot generally see the Waianae mountains, you are probably out of luck in receiving many DTV signals (KHET, KGMB, KHNL, KFVE, KIKU).

Space...the final frontier...

If you've ever passed by PBS Hawaii on the corner of Dole and University, you may have noticed a change in the roof line silhouette...we recently added another satellite dish to bring in more programming for you which will be announced in the next few weeks.

Hoisting everything up to the roof was a delicate process as the roof is actually a rubber membrane and is fairly delicate...

The base of the antenna contains over 8000 pounds of ballast so that the antenna won't move around in high winds...up to 120 MPH!

Once the base was constructed and properly placed...the assembly of the antena began, one panel at a time...

until it all came together...

Now we had to point it at the correct satellite which are spaced only 2-degrees apart in space...which makes it an even smaller increment of movement here on earth that is necessary to receive the strongest signal from the satellite we needed.  This process took almost 4 hours.

What makes putting together this type of antenna is all the bolts!  Gotta be over a thousand of them and unfortunately when you put something as intricate as this is together, you do it by keeping all the bolts and nuts loose until all the parts fit...then you go back and have to tighten each bolt in a certain order so as to not warp the dish and apply even pressure as each bolt is tightened. But it is all together now and working great!
 
We are in testing mode because not only did it take a full week to construct the antenna...it's taking time to make sure our automation system will record and playback the programs we want...so stay tuned as we will announce the new programming to start in early April...

Digital TV in Kauai

I'm back from Kauai where I just spent 5 full days installing a new digital television transmission system beginning with our system on Mt. Kahili.

It took multiple helicopter rides to get all the new equipment up to the site and the old equipment down.  Then we spent the entire day with absolutely no creature comforts (no bathroom, no food, restricted liquid intake and no access to warmer clothing).  Finally at about 5PM, the system went on-the-air successfully so everyone in Lihue, Kalaheo, Kaumakani, Hanapepe and beyond should be able to receive the PBS digital transmission.

Anahola's system was replaced the next day and officially went on-the-air at 6PM, Wednesday 12/16.

Kilauea, by way of a new digital relay station in Moloaa, went on-the-air on Thursday at 7:30PM.

Finally on Friday we were on our way to Princeville to finish my digital TV installations when we discovered that the mounting hardware for the antenna was not compatible with the tower...so while the translator is ready to go, I need to get some steel fabricated so that the new antenna can be mounted to the tower.  Once that is completed (sometime in mid-January) my digital TV transmission upgrade will be completed and on to the next project we'll go....

More Changes in What you are Seeing...

We reprogrammed some of our computers in Master Control to try and address the "postage=stamp" video many of you have been experiencing on cable channel 10 and 90.

Let me know if this has improved viewing PBS Hawaii programming for you...

Hawaii Island Digital Upgrade

It's done!!!  We completed the digital over-the-air upgrade at 7:30 PM tonight...There are still a few issues that we have to address, but for the most part, Hawaii island is now all digital, so you will need to either have a digital TV or a converter box to watch our over-the-air signal.

For those of you that do have a UHF antenna and digital TV, you will need to execute a channel scan to acquire our new channel frequency into the memory of the TV.  It will show up as 10.1 and 10.2 on your digital TV's display.

This digital upgrade can provide you with a great looking picture as well as additional program streams (10.1 is our main channel in HD and 10.2 is a PBS Hawaii Kids channel, for now)...but digital also has its drawbacks which you can read about in my previous entries including the Cliff Effect, which will be the most irritating artifact of the upgrade.

For those of you not familiar with the Cliff Effect, unlike an analog signal which can be viewed when the signal reception is poor, with digital, you either have it or you don't.  I'm hoping that most of you will get it...as predicted by FCC computer models.

I'm headed for Kauai tomorrow and will begin Kauai's upgrade on Tuesday...

So what am I seeing on Oceanic Cable...

For Oceanic Cable viewers, it depends upon what you are watching...HD Ch. 1010, Digital Channel 90 or Analog Channel 10.

As of Nov. 2, most of our programs come to us in a true HD format (16:9 - wide screen).  When we show any of the new HD programs on cable Channel 1010, you will see a full, side-to-side, top-to-bottom picture on your HDTV.  When we have to show a (4:3) picture on the HD channel, you will see it with black bars on both sides of the picture (pillar-boxed)...but you are still seeing the whole picture as it is meant to be seen.  The other type of picture you may experience is when a program that was made in a wide screen format, but was meant for a 4:3 screen.  Producers did this prior to being able to show true HD quality pictures but needed a wider screen, like movies).  This method starts with black bars on the top and bottom of the picture (letter-boxed) and then when it was changed to HD, black bars on the sides were added to make up the entire HD screen.  This is what we call the "postage-stamp" effect and we try to avoid this as much as possible.

For viewers of digital Channel 90 or analog Channel 10, it gets more complicated.  Because our signal is basically now a HD formatted picture, we need to convert it to display on your on your non-HD television set.  This is where we locally have the choice to decide how you see the program...we can either take just the middle of the picture to show you...this is called "center-cutting" or we can shrink the picture down until it fits, width-wise, on your screen.  This is called "letter boxing", black bars on the top and bottom of the picture.

Why not just use the "center-cut" option?  We want to show you the entire picture as it is meant to be seen and when there is picture and words that exceeds the 4:3 center-cut boundaries, your non-HD TV will not show this portion of the picture and important video could be cut from your viewing...so using the "letter-box option leaves you watching a smaller picture in the middle of your TV, but seeing the entire picture as it was meant to be seen.

So what's correct?  Both!  We are trying to find a solution that can accommodate the style of display to maximize the screen dimensions you have.  To do this, many things must come together including the acquisition of more HD programs and the purging of the old non-HD programs.

So until that time, there will be moments when the picture may not fill your screen, or parts of the picture may get cut-off.  You will see this type of thing happening on every channel you watch (though you will not know because you don't have a wide screen to compare it to) and as the TV broadcast industry struggles to implement new protocols, we will be susceptible to all the problems I have mentioned above.

So...what am I seeing now???

This is a good question.  We completed our Master Control HD Upgrade during the first week of November.  We are now in the process of acquiring new HD programs...so what happened to the old programs?  The new system utilizes a better method that lets us have more control over the HD programs than the old system and method...so we had to get rid of most of the old programs that we have been using for the past few years...so what are you seeing on the tube?

It depends upon your delivery system.  Are you receiving us over the air from one of our transmitters or translators?  Are you receiving us through Oceanic Cable?  Or maybe you are receiving us from Dish Network or DirecTV?  Then, what are you watching us on?  A new 16 by 9 (16:9) digital TV set?  Or maybe your older analog, 4 by 3 (4:3) TV set?  Or maybe through your computer?  Each one of these will cause you to see the picture differently.

Let me explain the over-the-air HD signal first.  This signal comes to you as either 11.1 or 10.1.  If you view us via an antenna connected to your converter box, the box will automatically output just the middle portion of the picture.  It cuts off the sides because the picture it receives is too big to fit on your analog TV...thus you may see some words and picture being cut off on the edges.  If you have a digital TV, then you will see the entire picture as it was meant to be seen.

Now DirecTV and Dish Network subscribers are seeing the same thing.  If you subscribe to their HD service, then you will see the entire picture as it is meant to be seen.  If you do not subscribe to their HD service, you are seeing that what they do to the picture is exactly what the converter box in the above scenario is doing, since they both use our over-the-air HD signal to put on their system and use a converter box to give them the picture they need for their analog service.

Now, if you are like most people, you subscribe to Oceanic Cable.  I will discuss this in my next entry since it is very involved.

It's All Coming Together

As you can see by the picture...

...as compared to my previous pictures...we have pictures on my screens!

We actually began to use the upgraded Master Control system late Sunday.  I apologize for all the program discrepancies throughout last week, but I believe we have cleared the last high hurdle and will be totally transitioned back to our Master Control sytem later today.

There will probably be some low hurdles to clear in the next couple of weeks and from later today we will start acquiring more and more HD programming to provide you with the best viewing experience of PBS Hawaii...stay tuned.

Knee Deep in Wires

It has been a few days into our Master Control upgrade and we are fairing pretty well...some transitions have been a little rough, but the programs are managing to get on the air as scheduled.  There have been issues with viewers not understanding what we meant when we said there would be program changes during the week of upgrades...but it is only a temporary change until we finish the upgrade process...so hang in there...we're getting closer to returning to normal.

Here is a picture of our Master Control...as I titled this post...we're up to our knees in wires

and notice the "black" screens...nothing coming out or going in!!! 

 
It's a bit disconcerting, but I know we'll be better off once we restart the system later this week. 

Digital is Coming to Kauai and Hawaii

When the FCC mandated digital television for the American public, there were more TV stations than channels available to make the transition to digital smoothly, so they let the "full" power stations convert first (June 12, 2009 was the end of analog broadcasts for full-power TV stations).  There were about 1750 stations to make this transition.  Now its time for the low-power stations to convert...6600+.  Though the FCC has yet to set a deadline for this transition, they have opened the door by asking for stations to begin applying for Construction Permits for digital low power stations, which includes PBS Hawaii's translators on Kauai and Hawaii.

Our equipment to transition our over-the-air broadcasts to digital has started to arrive and once I hire a contractor to install the receive and transmit antennas, the transmission lines connecting the translator to and from the antennas and installing the translator itself...PBS Hawaii will be completely in digital...ahead of any FCC schedule and broadcasting our HD signal to the entire Hawaiian Island chain.

When do I expect to accomplish changing out 6 translators on Kauai and four more on Hawaii?  If the weather holds out, it should all be completed sometime in mid to late December.  So all of you viewers with analog TV's will need to get a new digital TV or a digital-to-analog converter box to watch our over-the-air signal.  In addition, it might be a good time to check up on the health your UHF antenna and coax cable, making sure that there is a good solid, corrosion free connection at the antenna and to your TV...more to come once I start installing the translators...