Posts Tagged ‘Antenna’

Memo to 3D TV manufacturers: First, you build the highway. Then, you build the cars!

The latest PR blurb from CEA headquarters shows that, in a survey taken of 250 sales associates in retail stores, consumer enthusiasm for 3D is strong, with 50% of customers reporting a positive response to 3D technologies, and only 2% reporting a negative response.

That’s not necessarily good news. Do the math, and you’ll see that 47% of customers had no feelings about 3D TV one way or the other, or didn’t respond. (Or were distracted by their teenagers repeatedly begging Mom and Dad for an iPhone or iPod Touch.)

The CEA report does go on to say that “…While nearly 70 percent of sales associates feel well trained to answer questions about 3D, there is still consumer confusion. According to the retail associates interviewed, roughly half of consumers had some confusion about the technology.” That pretty much covers the 47% who didn’t respond positively or negatively.

And now for the devil in the details! “…For most retail associates, 3D content is pivotal. Nearly 80 percent of the associates interviewed believe sales of 3D technologies will not be strong until more 3D content is available.  Moreover, some of the most frequently asked questions by consumers revolved around the availability of 3D content. “

World Cup in 3D…Been there, done that. What else ya got?

There’s the rub. 3D may look great in the store, but how much 3D World Cup coverage can you watch before nodding off? (Hey, did you catch Paraguay and Japan fighting to a 0-0 tie?) And there are only a couple of 3D Blu-ray discs out there that haven’t been exclusively linked up to a 3D TV bundle promotion.

DirecTV is taking some steps to solve the problem today, announcing the launch of its 24-hour 3D channel in conjunction with Panasonic at a New York City press event. That’s good news for DirecTV customers, but it’s not much help to cable or Dish Network subscribers who are currently limited to ESPN 3D.

If this seems like déjà vu all over again (apologies to Yogi Berra), it is. Remember the start of the digital TV transition in 1998, when exactly two DTV stations went on the air? (For trivia buffs, they were WRAL (CBS) in Raleigh, NC, and WFAA (ABC) in Dallas-Ft. Worth, TX.)

Set-top boxes cost about two grand. You needed component inputs on your TV that could accept the 1080i signal from the box (good luck with the 720p outputs), plus an antenna, and maybe a preamp, and a bunch of coax, and a compass to tell you where to aim the antenna.

Oh, and yes – you needed HDTV content. But there was very little of it back then, aside from some CBS prime-time programs and the ABC Saturday Night Movie. It wasn’t until four years later (2002) before most of the TV networks were carrying a majority of their evening programs and sports coverage in HD. Can 3D TV manufacturers afford to wait that long?

It’s encouraging that 70% of the sales associates interviewed by CEA felt competent enough to answer questions about 3D. But that’s not the problem, based on my experience last Sunday at Best Buy. Only two out of four 3D TV demos in the store were actually working, and one was located in the worst possible spot for a demo. The other had only one pair of working 3D glasses. How do you answer questions about 3D, when customers can’t even see a demonstration of it?

This is where a company like Sony has a leg up with their Sony Style company stores. They can ensure (and they’d better!) that potential customers get the best possible 3D demo, with a large screen LCD TV and comfortable seats positioned at the correct viewing distance. And they can put together a nice mix of live 3D (Sony is a World Cup sponsor) and clips from Sony Pictures 3D movies (think Cloudy with a Chance of Meatballs).

Samsung’s ‘experience’ store in the Time-Warner Center in New York City is also an excellent place to demo 3D. (Hmmm. Maybe Samsung should be thinking about opening their own company stores!) Alas, Panasonic has no such showcase and is at the mercy of Best Buy and Sears. And Mitsubishi (who has some of the most compelling 3D TV value propositions right now) has no 3D showcases at all. (Too bad they can’t just truck their June NYC line show around the country!)

Now, THIS is how ALL 3D demos should look. (Dream on…)

But all the demos in the world won’t do any good if there is nothing to watch in 3D. And for the vast majority of potential 3D TV customers, there just isn’t enough to watch in 3D right now, so the credit cards and checkbooks are staying in pockets and purses.

Hopefully, that problem will sort itself out by year’s end, when we should see a flurry of 3D BD releases, more coverage of sporting events, the launch of Discovery’s 3D channel, and maybe even some 3D streaming from Netflix. (That last possibility assumes Netflix can get over some significant technical hurdles, such as bandwidth.)

Hint to TV manufacturers, and to Fox Sports: S-U-P-E-R B-O-W-L I-N 3-D. (Think that was subtle enough?)

So, we’re back to 1998. Grab some shovels and picks, and let’s get started on those highways! (Maybe there are still some stimulus funds available?)

The DTV Transition: One Year Later

Many HDTVexpert.com readers know I started this Web site back in 2004 as a way to provide useful information on HDTV – how to receive it, how to watch it, and how to get the most out of it.

As it turned out, the most popular articles were (and continue to be) “how to receive digital TV” tutorials. More specifically; how to select and use antennas for over-the-air DTV reception.

Over this past Memorial Day weekend, I had a chance to visit the site of one of my more interesting DTV reception challenges. The house, located high in a steep valley in southern Vermont, is completely blocked-in by a ring of hills and sits 50+ miles from the Albany, NY TV transmitters atop Helderberg Mountain. (Well, most of ‘em are up there.)

The occasion was to install a new flat screen TV and tap my ground-level UHF/VHF antenna system one more time to provide free HDTV to that screen. (The other two taps drive Zenith converter boxes.)

Sure enough, after a few hours of stringing cable and drilling holes, my brother and his wife were able to watch the French Open in HD via NBC affiliate WNYT and the Indianapolis 500 in HD from ABC affiliate WTEN. I also tossed in an upscaling DVD player so that they could enjoy their sizable collection of DVDs in widescreen ‘near’ 1080p quality.

That RF system is done – there’s nothing I can do to improve it, other than periodic maintenance and repairs. And other DTV antenna systems I’ve installed in upstate New York, on a Canadian island, in Maine, at the Jersey shore, and on the roofs of a few locals are perking along happily, with their owners enjoying one of the few great deals left in this world…free television, and in high-definition, too.

It’s a work of art, and a thing of beauty.

My own system is doing a bang-up job hauling in DTV signals from New York City (65 miles), Scranton (70 miles), Philadelphia (22 miles) and Allentown (25 miles). If I get tired of all the ‘hometown cheering’ for the Phillies and Flyers on local DTV stations, I can always switch back to New York DTVs WCBS, WNBC, WABC, and WWOR and get the scoop on the Yankees, Giants, and Knicks. (And if WMCN-DT wasn’t spewing out their inane infomercials on channel 44, I could watch WTXF as well!)

The future of over-the-air DTV isn’t very clear at the moment. FCC Chairman Julius Genachowski has called for re-allocating much of the UHF TV spectrum, to be used instead for wireless broadband to solve an Internet ‘connectivity crisis.’ (Verizon chairman Ivan Seidenberg has gone on record as saying that this ‘crisis’ is largely non-existent, and that Verizon isn’t even using all of the recycled TV spectrum it bought for such an application.)

Even so, we might as well enjoy OTA DTV while it lasts, which I hope will be a long time. So that brings me to the point of this essay, which is to ask readers this: How is the DTV transition working out for you? Are you connected? Everything running hunky-dory?

Or, are you still having problems with antennas, or older set-top boxes? Still trying to pull in DTV signals in a tough location? Got noise or co-channel interference issues?

Tell me about them. I’d like to hear your stories, and will publish as many as I can.Maybe I can even solve a reception problem for you, if I get lucky.

Drop me an email at pete@hdtvexpert.com with particulars (and photos as well, if you have them). I’d like to get a sense of how many readers are still watching free over-the-air DTV. And how many have opted to drop cable, or cut back on it in favor of broadband video services like Netflix or Hulu.

It’s a very different world we’re living in than ten years ago. Back then, we got excited when a temporary antenna, braced out on our decks or stuck in a low-hanging tree, intermittently pulled in HD broadcasts of Monday Night Football. Remember how revved up you felt back then when the signal finally locked up?

Somehow, Peter Griffin and Saturday Night Live streaming to my laptop doesn’t hold quite the same thrill…

Product Review: Three For DTV…Reception (February 2009)

I recently had an opportunity to test indoor DTV reception at a potentially “tough” location in New York City. This particular apartment requires an indoor TV antenna and sits about 3.5 miles from the Empire State Building, alongside Central Park.

The apartment is on a lower floor and next to several tall buildings that contain lots of steel and glass in their outer structures. The challenge was to come up with a model that would provide reasonably strong signals with minimal multipath, looking through or positioned just below a couple of small windows that face west, looking out over the northern section of the park.

Seeing as how RCA had just sent me their ANT1450B amplified VHF/UHF panel antenna (MSRP: $49.95), this seemed like a perfect location to give it a test drive. For more fun, I also packed up Terk’s HDTVa VHF/UHF indoor antenna (MSRP: $59.95) and Radio Shack’s “bare bones” 15-1874 VHF/UHF indoor antenna (MSRP: $11.99), along with a spectrum analyzer to accurately see how each antenna was working.

For test receivers, I packed up the AutumnWave OnAir Solution HDTV-GT receiver (5th gen) and my Acer notebook PC, plus a new entrant to the set-top box field – Aurora Multimedia’s V-Tune Pro HD ATSC/NTSC/QAM/IPTV receiver (MSRP $1,299). This box has RS232 controls and supports both component video and HDMI outputs – plus, it’s LAN-ready for streaming video and updating software and hardware.

THE LOCATION

The test apartment is currently undergoing interior re-decorating, so I simply placed each antenna near one of the two small living room windows and peaked it for best analog TV reception on as many channels as possible. The quality of each channel varied considerably, as you can imagine – multipath was so bad on some channels that it was difficult to get any reliable NTSC signals.

I then did channel scans with both the V-Tune Pro HD and the HDTV-GT, to see how many signals locked up both receivers. MPEG stream analysis was also done with the HDTV-GT and TSReader Pro, so I could check modulation errors. The results were surprising, to say the least.

The active DTV stations I was trying to receive included WNYE-24, WNBC-28, WPXN-30, WPIX-33, WNJU-36, WWOR-38, WXTV-40, WNYW-44, WABC-45, WNJM-51, WCBS-56, and WNET-61. Some of these stations have very strong signals, and I can pick ‘em up at home, 65 miles away in eastern Pennsylvania. Others aren’t quite as loud.

Figures 1a-b. Radio Shack’s 15-1874 “budget” VHF/UHF indoor antenna in a formal pose (top) and in action (bottom).

RADIO SHACK 15-1874

This antenna is about as simple as it gets. It consists of a small plastic base with a metal bottom, a thin-wire UHF loop that snaps into place, and a pair of thread-on, telescoping VHF rabbit ears. The 15-1874 is the kind of antenna many folks might use with NTIA DTV converter boxes, to replace their old, broken rabbit ears.

After peaking for best analog reception, I did a channel scan and was able to pull in 7 of 13 stations currently broadcasting digital TV signals from the Empire State Building, 4 Times Square, or other locations. For what it’s worth, two of the stations that didn’t make the grade (WNJU-36 and WNJM-51) currently broadcast from towers in New Jersey, and were just too weak to be picked up even though I spotted ‘em on the analyzer.

Figure 2a. Qualcomm’s MediaFLO service on UHF channel 55 (left waveform) and WCBS-DT on channel 56 (right waveform), as received by the 15-1874.

Figure 2b. DTV waveforms from WNYW-44 (left) and WABC-45 (right), as grabbed by the Radio Shack antenna. Note the strong tilt on WABC’s signal.

Figure 2c. WWOR’s digital signal on channel 38 was problematic, and that big notch in the middle of the 8VSB waveform was the reason – it kept fluctuating up and down.

Of the remaining stations, one (WNET-61) is operating with very low power and is beaming its signal west towards Newark, NJ – its city of license. I could see it on the analyzer, but it was just too weak to pull in. (WNET will go back to VHF channel 13 after the analog shutdown, and should be plenty strong in the metro NY area, based on tests conducted in early January.)

The other two stations (WPXN-30 and WWOR-38) just had tricky multipath that the RS-1874 couldn’t do anything about. After all, it’s basically a dipole antenna on UHF with little directivity. I don’t expect the rabbit ears to make that much difference with high-band VHF channels, either. Still, for $12, this antenna did a fine job and is a low-cost solution for city dwellers that live 10 or fewer miles from the transmitter site(s).

Figure 3a-b. RCA’s ANT1450B in a beauty shot (top) and on the front line (bottom).

RCA ANT1450B

I’d tested the non-amplified version of this antenna (ANT1500) back in the late summer, and found it wanting for indoor reception at my location. The ANT1450B also uses a similar etched strip-line VHF/UHF antenna design, but included an in-line amplifier module to boost overall signals levels.

Given that my home location is 23 miles and over a hill to the Philadelphia antenna farm, I figured the New York location would be a kinder test of the RCA’s abilities. Once again, I positioned it near one of the windows and peaked it for best NTSC reception, and then did a channel scan.

Figure 4a. WCBS’ digital signal on channel 56 was a real challenge for the ANT1450B.

Figure 4b. WNYW-44 (left) and WABC-45 (right) looked a bit better through the RCA antenna.

Figure 4c. WNYE-24 had a booming signal at the reception location.

The results? Without the companion amplifier, the ANT1450B pulled in 6 of the 13 available DTV stations, once again skipping WNET-61. It also missed WPXN-30, WNJU-36, WWOR-38, WFUT-53, and WCBS-56. This antenna is just as non-directional as the 15-1874, and equally susceptible to multipath. With re-positioning, I was able to pull in WCBS-56, but dropped WABC-45 and WPIX-33.

Adding the amplifier accomplished two things. First, I was now able to add WFUT-53 and WCBS-56 to my original list, although the latter channel showed “hits” now and then. Second (and unfortunately), the noise floor on VHF channels 7 through 13 was elevated by 20 dB! That’s not a good development, and one that spells trouble for WABC, WPIX, and WNET when they go back to their original high-band VHF channels 7, 11, and 13, respectively.

Figure 5a-b. Terk’s HDTVa antenna looks aerodynamic just sitting still (top) and like it’s ready for takeoff when in use (bottom).

TERK HDTVa

This antenna continues to impress me, although its UHF section isn’t much of a mystery – it’s the Antiference Silver Sensor, coupled to an internal amplifier. The VHF element is a bit more pedestrian, with a pair of telescoping rabbit ears. They are robustly built, though.

After waiting for the usual channel scan, I discovered both the Aurora and OnAir receivers had logged 12 of 13 DTV stations (nope, still no sign of WNET-61). More importantly, only two (WPIX-33 and WPXN-30) showed any signs of “hits” from time to time. Impressively, I could now watch WNJU-36 and WNJM-51, previously missing in action.

Figure 6a. WWOR-38 came in beautifully through the HDTVa.

Figure 6b. WNBC-28’s 8VSB waveform, although ragged, was rock-steady with the Terk.

Figure 6c. WNYW-44 and WABC-45 looked best with the HDTVa.

Although the HDTVa is vastly more directional than either the Radio Shack or RCA designs, its performance could be even better if it had a reflector behind its rear element. WPIX’ channel 33 waveform showed some pretty funky notches, and WPXN could have used a bit more signal overall. I also noticed hits on other channels that seemed to be tied to the passage of busses and trucks in the street below, but these primarily affected upper UHF channels (53, 56) that won’t be in use after June 12.

As well as the HDTVa performed, it also raised the high-band VHF noise floor by 20 dB or so, indicating the presence of some type of broadband RF emitter nearby. Perhaps that was a computer, or a security system sensor. (I’ve even seen high-band VHF RF emissions from a hand-held HD camcorder, believe it or not!)

Figure 7a. Here’s what the normal nose floor looked like underneath VHF channels 7, 9, 11, and 13.

Figure 7b. And here’s what the RCA and Terk amplifiers did to it – raise it up by 20 dB!

Figure 8. Aurora Multimedia’s V-Tune Pro HD did a creditable job pulling in the test DTV signals.

CONCLUSIONS

My tests at this site aren’t yet complete, and another round of testing will include antennas with improved directivity to help minimize multipath. But if I had to go with one of the test antennas, I’d pick the Terk HDTVa. It did the best overall job on UHF DTV and analog VHF signals, and the internal amplifier (although not a low-noise design) does make a difference – plus, it works a lot better than the in-line amp module RCA ships with their ANT1450B.

I was very impressed at how well the RS 15-1874 worked, but given its traditional design, a lot of the credit must go to the OnAir HDTV-GT and Aurora’s V-Tune Pro. Stand-along HDTV set-top boxes are getting harder to find these days, and one that’s integrator-ready like the V-Tune Pro are rare. It works very well, and its receiver is even a bit better with tricky signals than the Gen 5 HDTV, now two years old.

As for RCA’s ANT1450B, it would appear to work best in a location where it has a clear shot towards a transmitting antenna. Handling multipath is not its strong suit, but what can you expect from what amounts to a pair of folded loop antennas, mounted inside of each other’s radius? I’d skip the in-line amplifier unless you live in a less congested area – too much garbage gets pulled in and winds up degrading the noise figure of the receiver.

Radio Shack 15-1874

Budget VHF/UHF Indoor Antenna

MSRP: $11.99

http://tinyurl.com/2ml5re

 

RCA ANT1450B

Amplified VHF/UHF Indoor Antenna

MSRP: $49.95

http://tinyurl.com/b7ksnr

 

Terk HDTVa

Amplified VHF/UHF Indoor Antenna

MSRP: $59.95

http://tinyurl.com/arntk

HDTV Tech Talk: I’ve Got The Low-Band DTV Blues (June 2009)

One of the more interesting stories that has developed following D-Day (June 12) is the trouble that viewers are having in several large markets with low-band TV channels – specifically, channel 6, which is now digital in Albany, NY; Philadelphia, PA, New Haven, CT, and five other TV markets.

There have also been reports of difficulty with stations on channel 7, most notably WLS in Chicago and WABC in New York City. The situation there is quite different, but we’ll take a quick look at it at the end of this article.

THE OP-ED SECTION

First off, let it be said that the FCC’s decision to retain channels 2 through 6 in the DTV channel core was ill advised. These are some of the oldest TV channels in existence and used to be the prime spots for a TV station, since they were the lowest channel numbers on tuners.

But the frequencies in which these channels are located – specifically, from 55 MHz to about 88 MHz, give or take several kilohertz – have long been plagued with impulse noise, such as you’d get from noisy fluorescent lamp ballast, brush motors, or any electronic equipment that creates inductive voltage spikes.

To make matters worse, seasonal signal propagation enhancement, caused by sporadic ionization of the ionosphere’s E-layer, can cause signals on these frequencies to hop across the country and create co-channel interference many thousands of miles away. Ham radio operators like myself refer to this summertime phenomenon as “E-skip,” for short.

Here’s another reason why channels 2 through 6 should have been retired: They require very large antennas for efficient reception. A full-wave loop antenna for channel 2 (56 MHz) would measure 5.4 meters in length, or about 17.5 feet! (Contrast that with a full-wave loop for UHF channel 42, which would be about 18 inches around.)

This makes it problematic to design an indoor antenna with any kind of gain, short of adding an internal amplifier. Unless that amplifier’s design is bullet-proof (and for normal Radio Shack prices, it usually isn’t), the antenna system will be overwhelmed with noise and interference from other nearby RF signals, such as FM radio stations.

THE CHANNEL SIX CONUNDRUM

But that’s water under the bridge now, and 40 stations have decided to stay put on this not-so-valuable real estate. As a result, I’m getting quite a few emails about some bizarre low-band VHF reception issues.

My favorite so far is from a television station monitoring service, whose rooftop channel 5 antenna in West Virginia is being routinely wiped out every day by fluorescent lights in the Ace Hardware below, during normal store hours. (Not impossible to fix, but it will take some detective work.)

Getting back to my home market of Philadelphia, there are plenty of problems with reception of WPVI’s digital signal on channel 6. And it became evident pretty quickly that WPVI was having these problems just 24 hours after shutting down their analog signal on channel 6.

Subsequently, WPVI and CBS affiliate WRGB in Schenectady, NY (also on channel 6, and also experiencing reception issues) applied to the FCC for an emergency authorization to go to higher power.

According to  a news story in the June 22 issue of Broadcasting and Cable magazine, “…The FCC granted the station (WPVI) a special temporary authority (STA) to boost its transmission power on Ch. 6 from the relatively low 7.5 kilowatts (kW) to 30.6 kW, the maximum power for the northeastern “Zone 1” region of the U.S.”

Figure 1. WPVI’s DTV signal on VHF channel 6, seen at 1:00 PM on June 12. Each of the sharp, rounded signals to its immediate right are FM radio stations.

WPVI’s original digital signal on June 12 at 1 PM, as seen in Figure 1, wasn’t too shabby to begin with, and I could receive it quite easily on both my rooftop and attic antenna systems. It also came in nicely near the southwest wall of my house, on both floors, while using Eviant’s T7 Card portable digital TV set.

But there are always devils in the details, and you can see them quite clearly immediately to the right of WPVI’s flat-topped 8VSB carrier. Those numerous rounded peaks are FM broadcast stations, the closest of which is on 88.5 MHz (WXPN). Almost immediately adjacent is WRTI’s FM operation on 90.1, followed by WHYY on 90.9, etc.

So, what’s the problem? Those FM stations are co-located at the Roxborough TV tower farm, NW of Center City. And they present very strong signals that can slip through the filters in NITA converter boxes, resulting in interference to the channel 6 signal. What’s more, FM and TV signals mixing in converter box receivers will produce sum and difference frequencies that wind up right in a portion of the channel 6 spectrum.

So what’s likely happening is that closer-in TV viewers, who probably don’t have really long rabbit ears (a full-wave loop @ 85 MHz measures 3.53 meters, or 11.6 feet) are trying to pull in a signal that’s competing with strong, adjacent-channel signals from FM  broadcasters. Toss in the usual elevated noise floor from arc lamps, power transformers, air conditioning compressors, and refrigerator motors, and you have a sticky wicket indeed!

Figure 2. WPVI’s “boosted” DTV signal, as seen at 9:45 AM on June 22. It’s about 6 dB stronger than before.

Figure 3. This wide view of the TV spectrum from channel 2 to channel 13 shows how strong WPVI’s new signal is, compared to WBPH-9 and WHYY-12 (far right).

WPVI’s Special Temporary Authorization (STA) from the FCC definitely resulted in a stronger signal, as seen in Figure 2. And Figure 3, which shows a wider view of all low-band and high-band VHF channels, plus the FM band, reveals that WPVI’s broadcast is now the strongest TV signal coming out of Philadelphia. (Notice the comparatively weaker signal from WHYY-12, the 8VSB carrier to the far right.) But is WPVI even strong enough now?

In both of my spectrum analyzer screen grabs, you may notice that the FM radio station carriers get progressively weaker as the frequency increases. That’s because I’m using an FM trap to try and attenuate them. But that filter simply isn’t sharp enough to subdue WXPN, WRTY, and WHYY without also affecting the strength of WPVI’s signal.

Only precision signal filters with multiple poles and what we call “Hi-Q” sharp filter skirts can solve this problem. Except that filters like that are VERY expensive to manufacture, and not something you’d put into a $59 converter box or a $500 TV set.

The adjacent channel overload problem is compounded by the use of circular signal polarization from FM stations. This is done among other reasons so that their broadcast signals remain moderately stable in as your drive around in your car. But that’s no help to the home TV viewer, who may try to no avail to weaken the FM signals by positioning their TV antenna horizontally or vertically.

Figure 4. A spectral view of WRGB-6 in Schenectady, NY, also “up against it” with multiple strong FM stations in close proximity.

In case you think this is just a “big city” problem, look at Figure 4, which shows the FM carrier immediately upstream from WRGB-6 in Schenectady. Same problem – multiple strong FM stations that can play havoc with converter boxes and integrated TV sets are located immediately adjacent to WRGB’s 8VSB carrier. And similar complaints about lost reception are coming into the chief engineer’s office up there.

OK, SO WHAT DO WE DO NOW?

Unfortunately, there isn’t any “one size fits all” fix to this problem. But there are some things that may work.

Inline signal attenuators: First of all, ATSC signals will come through at very low carrier-to-noise ratios, where analog NTSC signals won’t. It stands to reason that viewers close to the TV antenna farms have more than enough signal to begin with, so the counter-intuitive approach is to add attenuators inline with the antenna leads.

This will result in a weaker signal on channel 6, but will also drag down the levels of FM stations, too. Toss in an inexpensive FM notch filter, and at some point the TV receiver or converter box may be able to make better sense of the differences between the FM and channel 6 8VSB signals.

Of course, for this to work correctly, the attenuator should only be in the VHF antenna line, because it’s also going to clip signals from every TV station upstream from the filter, including high-band VHF and UHF. The VHF antenna should also be horizontally polarized, and not vertically polarized. That means flattening out those rabbit ears, or using a bar antenna or folded dipole on the roof, or in the attic.

Eliminating noise: Another possible problem is broadband noise, as I mentioned earlier. It’s worth checking out DTV reception problems with as many of your home appliances and lights disconnected as possible, to see if some “hash” isn’t getting into your system and creating interference problems.

Such interference would manifest itself on the FM band (Surprise! FM isn’t completely noise-free) as well. Any offending appliances should be replaced or repaired, because they’re likely creating bigger interference problems with other electronic devices in and nearby your home.

Using the wrong antenna: Of course, in more than a few cases, the problem seems to be one of trying to receive VHF channel 6 with a UHF antenna, which of course is akin to trolling for marlin with a Pocket Fisherman.

Many folks don’t realize that WPVI is now relocated a long ways away from its former position on UHF channel 64 (about 771 MHz), and that the small UHF loop antenna that used to work so well to pick up Jim Gardner and Action News is little more than a piece of decorative aluminum when it comes to watching VHF TV channels.

So what’s needed is a pair of longer rabbit ears, or even better yet, a folded dipole antenna that can be mounted on the side of a house, or in the attic – or even on the roof. The size would be ½ the length of a full-wave loop, or about 5 feet 9 inches. (5 feet is close enough for government work.)

This folded loop can be made out of copper tape, aluminum, or stiff wire – anything conductive. Even refrigerator drain hose (also copper) also works. Simply solder the leads of a 300-ohm coaxial balun to the open ends of the loop and run a piece of RG-6 to it, and you’re in business. Here’s a link to a simple folded dipole design, made from TV ribbon wire (twin lead). It’s scalable to any VHF channel.

Of course, you can also try a pair of conventional rabbit ears, but if you’re close in to the TV station (10 miles or less), stay away from amplified designs. They’ll only make the problem worse. On the other hand, WRGB’s chief engineer reported at least one viewer had complained about losing the signal on his rabbit ears antenna…30+ miles away. In that case, the amplifier is a good idea, but a rooftop or attic antenna is a lot more sensible.

MEANWHILE, BACK AT THE RANCH…

The problems that have been reported with reception of VHF channel 7 in New York City and Chicago appear to be arising from either improper antenna selection, or elevated noise floors, a common problem in cities. VHF signals have a tough time penetrating tall buildings, a task that UHF signal seem to handle with more aplomb.

But once again, a UHF antenna is not even close to resonance at 180 MHz (Channel 7). That’s about 1.67 meters, or 5.5 feet for a full-wave loop antenna. The good news is, everyday rabbit ears will usually do the trick here, but you’ll need to experiment with their polarization to see what works best. Fortunately, there aren’t any pesky FM radio station carriers lurking nearby.

What there IS, however, is lots of broadband noise. Figure 5 shows a spectral view of analog channels 7 through 13 in New York City, about 3.5 miles northeast of the Empire State Building, inside a 3rd-floor apartment where I’ve been researching an indoor TV antenna design.

Figure 5. Here’s a view of the TV spectrum from channel 7 through 13, as seen from the upper reaches of Fifth Avenue in New York City.

Figure 6. Whoops! Adding a preamplifier didn’t make matters better; it made them worse by elevating the noise floor.

So far, so good! But I wanted a little bit more separation between TV carriers and noise for more reliable DTV reception and to feed multiple TVs. So, I tested an inline preamplifier – with disastrous results. Figure 6 shows that the amplifier boosted channels 7 through 13 by almost 20 dB, but also kicked up the noise floor by the same amount – basically accomplishing nothing.

Lesson learned? I’ll have to come up with most of the gain in the antenna system, and try with different combinations of attenuators and preamps to see how I can add some “active” gain to the system without adding more noise and creating a new set of headaches.

I’ll be conducting more tests on channel 6 reception and also high-band VHF stations during the summer to see what practical solutions myself and others can come up with. Look for more coverage of this issue later in the summer. In the meantime, email any questions and observations you may have about “difficult” DTV stations, so we can share them with other readers.

Classic Product Review: Eviant T7 Card Portable Digital TV (2009)

It’s finally over. The United States has transitioned away from analog (NTSC) TV broadcasting after 60+ years, and moved to an all-digital system (8VSB) for full-power TV stations. (Low power and translator stations are still analog for a few more years.)

The NTIA converter box program is slowly winding down, and the latest estimates from Nielsen (June 21) showed that about 2.1 million homes, or 1.8% of all over-the-air TV viewers, were still unable or unprepared to watch digital TV.

The upside? Over 62 million converter box coupons had been mailed as of June 24, with 32 million redeemed and 24 million expired. And of course, every new TV set that supports NTSC reception must also support the ATSC DTV standard. So, we’re out of the woods with DTV reception issues, right?

Not quite. Everyone that ever bought a portable TV, from Sony Watchman LCD sets to tiny tabletop CRTs, just saw their investment reduced to zero on June 12. None of these legacy sets can receive ATSC signals, and it’s impractical to connect an NTIA converter box as a “retro move,” since there’s only one model that can run off batteries.

Never fear; Eviant is here! The company recently introduced two new LCD portable TV sets that are fully ATSC-complaint. Both sets are being featured as “hurricane TVs,” or sets you should keep around in case of a weather emergency.  But they’re also good-looking and small enough to use for everyday viewing on the go.

The T7 “Card” is the larger of the two models and the one that’s currently shipping to retail. According to the press release, “…The Eviant “Card” series 7-inch digital portable TV is available now in leading retail outlets including Kohls, JC Penny, Walmart.com, Target.com, Belks, Aafes, Bon Ton, D&H, HSN, Amazon.com, Shopko, Marsan and more with a MSRP of $169.99.”

Figure 1. Eviant’s T7 “Card” portable digital TV, shown in a white finish.

OUT OF THE BOX

Eviant’s T7 is about the size of a thick paperback book, and not all that heavy. It measures 7.3 inches wide by 5.7 inches high and is 1.1 inches deep. With the included lithium ion battery, it tips the scales at just over a half-pound. The supplied lithium ion battery charges up quickly (less than one hour), and is supposed to provide 2.5 hours of viewing time between charges.

Eviant has shown this TV with different color finishes. The official press photo shows a white housing, but my review sample was black and I also saw a red version at the CES summer line show. The shipping box shows pink, blue, and green as additional “skin” options, so you can knock yourself out with color coordination options!

The T7 isn’t just a TV. Eviant has also included a composite video input and mini audio connection to go along with it, plus a matching cable. If you have a portable media player with these connections, you can at least watch your videos on a larger screen. There’s also a mini-stereo headphone connection for private listening.

The whip antenna is actually a slide-on whip, which means you can pull it off and hook up other types of antennas to the threaded F connector. (Bravo, Eviant!) Eviant’s also included a little vertical UHF antenna with a magnetic base that you can stick just about anywhere.

The TV has a swing-out support stand for tabletop use. There’s even a credit card-sized remote control that has extremely limited functionality — basically, you can adjust volume and channel, plus access the menu. There isn’t even a power button on the remote (strange!), but there is a “channel +10” button for moving around faster.

The LCD display measures 7” and has a working resolution of 480 x 234 pixels, so don’t go crazy expecting to see HDTV on this product. Remember — it’s a portable TV, first and foremost. Besides, trying to put a 7” HD display in a product like this would be overkill.

Figure 2. The T7 (and its “coming in the 3rd quarter” 4.3” companion) grabbed more than a few eyeballs at the CES NY Line Shows in early June.

MENUS AND OPERATION

Eviant has included a surprising detailed menu. There are five sections you can diddle around with — Picture, where you can select the AV input or regular TV mode, plus choose between Personal, Dynamic, Standard, and Soft image presets, and fine-tune contrast, brightness, and color.

The Audio menu is where you can adjust balance, plus select the preferred language when more than one audio track is available. The Clock menu lets you set the OSD duration in 15-second increments, plus toggle to your time zone and switch Daylight Savings Time on and off.

The Tools menu is where you can set the OSD transparency (on or off), color temperature (Warm, Normal, Cool), and the picture Zoom mode for when 4:3 content is displayed on the screen. The default (factory) setting for this control is Wide, but you can switch everything (including HD broadcasts) to 4:3. Or, you can just select Auto, and let the T7 provide the correct screen size, based on the video format being transmitted.

The last menu, Channel, is where you’ll scan for ATSC and NTSC channels. Believe it or not, the T7 will also scan for and receive NTSC and QAM digital cable channels (handy for when there’s a cable TV feed near your campsite, I guess?). The NTSC support means you’ll still be able to pick up local community TV stations, which converter boxes won’t receive.

You can initiate a general channel scan in this menu, and also an overlay scan to pick up any channels you may have missed the first time around. This secondary scan is also handy if you rotate antennas or travel, and don’t want to lose digital TV channels you captured previously.

PERFORMANCE

I first tested the T7 by connecting it to my attic antenna system, which feeds my home office. It takes a while to scan — about two and a half minutes to saunter through channels 2 through 69 — but once done, works as well as any PC-based digital TV tuner I’ve tested. As you step through channels, you’ll see a blue display in the upper right corner of the screen showing you each station’s virtual channel number and call sign.

One thing you won’t see on the T7 is PSIP. For whatever reason (and it may be that cost is the reason), there is no way to display electronic program guide information on the T7. It will, of course, display closed captions. But the only way you’ll know what you’re watching is to change the channel up and down to get the virtual channel display to appear briefly onscreen again.

The next step was to connect the T7 to my rooftop antenna via a splitter, with the other leg feeding a Zenith DTT901 DTV converter box. My goal here was to see how the two compared in terms of sensitivity and ability to handle multipath.

The answer? They were equivalent in performance on both close-in and distant DTV channels. I installed a 20 dB step attenuator in line to both sets and began cranking back signals 1 dB at a time until they started to break up or drop out. That point was exactly the same for every channel on both the T7 and the DTT901( the latter is effectively running Generation 6 8VSB receiver technology).

An inquiry to Eviant’s PR firm came back with the response that the receiver’s chipset is made by MStar Semiconductor of Taiwan, and is the MSD110. From my tests, it appeared functionally the equivalent of the LG 8VSB front end used in the DTT901.

The next test took place during my Super Tuesday session at InfoComm. The session, attended by 180+ people, was held in Room 303 of the Orlando Convention Center. I scanned for channels and picked up over 25 different NTSC and ATSC programs, most of which played just fine without any dropouts, no matter where I placed the TV in the room. (This location is over 20 miles distant from the Orlando TV transmitters.)

Figure 3. Yep, I was able to watch snippets of “Wipeout” on WABC-DT, while zipping along in a double-decker train through the Jersey Meadows!

Figure 3. Yep, I was able to watch snippets of “Wipeout” on WABC-DT, while zipping along in a double-decker train through the Jersey Meadows!

The final test was to take the T7 into New York City for some press meetings. One was uptown at the Hilton Times Square, and the others were at the Metropolitan Pavilion on 18th Street. Reception was perfect on 42nd Street by Times Square on all channels, including high-band VHF channels 7 (WABC), 11 (WPIX), and 13 (WNET). Reception deep in the Hilton was spotty in places, but still better than I expected.

Later on that afternoon, I plunked the T7 on the wooden bar of an Irish pub on 18th Street, as our group tossed down a quick round of Harp lagers before Pepcomm’s Digital Experience opened. Once again, I experienced flawless reception of all NYC DTV channels with the whip first extended halfway, and then fully extended. (The T7’s whip is actually more resonant at UHF frequencies when somewhat collapsed).

Just for laughs, I pulled the T7 out seconds after my westbound, double-decker NJ Transit Midtown Direct train exited the New Jersey side of the Hudson River tunnel. I flipped it on and was able to watch quite a bit of programming on WABC-7 and WPIX-11, even with the train moving at a pretty good clip — 50+ miles per hour. I could see the Empire State Building through the opposite train windows for a good part of the trip, so I figured it was worth a try.

Of course, signals were lost completely when we went through the Secaucus train station and also when we crossed lift bridges and went under other tracks. But the video and audio were there about 70% of the time. And once the train pulled to a complete stop in Newark to take on and pick up passengers, VHF and UHF DTV reception was rock steady.

CONCLUSION

Eviant’s T7 delivers the goods. It has an excellent DTV receiver front end and worked very well indoors in what are difficulty high-multipath environments (Times Square, 18th Street, and the Orlando Convention Center). Audio is surprisingly loud for such a small TV, although frequency response is limited. Images were very clear and crisp, even at low resolution.

What I didn’t like: Even with a +10 channel jump button, it takes a while to move from one channel to another. There should also be a power switch on the remote control. And I’d like to see at least a “mini program guide” button included, so you at least find out what the heck program you’re watching.

The time (broadcast by every digital TV station) isn’t even displayed, unless you go into the menu. Oops! That info would be very helpful on a “hurricane TV.” Oh, and by the way, Eviant — how about a car charger adapter for this TV, in case of a power failure that lasts more than 2.5 hours?

In any event, the T7’s faults aren’t deal breakers. From what I’ve been told, pricing is very competitive on this product — a quick check online shows Target pricing them at $149.95, and Amazon had the black version listed as low as $119. For that kind of money, you can’t go wrong.

SPECIFICATIONS

Eviant T7 Portable Digital TV
MSRP: $169.99

Specifications:
Dimensions: 7.3” W x 5.7” H x 1.1” D
Weight: .55 pounds*
RF Input: “F” connector with fitted collapsible whip
TV Systems: NTSC, ATSC, QAM
Video inputs: (1) Mini-plug
Audio inputs: (1) stereo mini-plug
Audio output: 8-ohm stereo mini plug
* Owner’s manual says .55 pounds, press release says 1.39 pounds

Available from:

Eviant
1661 Fairplex drive
La Verne, CA 91750

www.eviant.com
(866) 935-4396