A decade after broadcast television in the United States went completely digital, the delivery system continues to evolve. In 2009, the UHF TV spectrum shrank to channels 14 through 51, with higher channels auctioned off for other services (including at one time, a subscription TV package on former channel 55).
Now, we’ve just completed another FCC spectrum auction, and channels 38 through 51 are history as of 2020. That means broadcasters are scrambling to find new homes, many of which won’t be in the UHF spectrum. On top of that, a new version of the ATSC standard (3.0) has been developed, tested, refined, and adopted by the FCC. As I write this, nearly two dozen experimental ATSC 3.0 broadcasts are taking place around the country, with several stations “lit up” in Phoenix alone.
From the consumer perspective, cord-cutting to save on monthly cable bills continues to gain popularity, albeit slowly. Some cord-cutters are old enough to remember watching over-the-air TV with antennas, while younger viewers are switching to streaming video over fast Internet connections. The savviest of all combine free off-air broadcasts with streaming, and that’s where the SMARTenna+ comes in.
The SMARTenna+ installed on a high wall. Yes, you can use push pins!
BUT FIRST, A LITTLE RF SCIENCE
Almost twenty years ago, I began testing indoor and outdoor antennas to determine the best models. Along the way, I’ve come across some very utilitarian and affordable products, while others had elaborate and complicated designs that failed to deliver. Most of the expensive antennas I’ve tested simply aren’t worth the money, and here’s why.
Regardless of the digital modulation format used to transmit a television signal, the radio frequency (RF) carrier wave behaves predictably. At lower frequencies – say, VHF channels 2 through 6 – the full wavelength of the signal is quite long, ranging from almost 6 meters (18 feet) to 3.5 meters (11 feet). So it stands to reason that an effective antenna design would have the same length or close to it for the active reception element.
That element could be a half-wave dipole (9 to 6.5 feet), or a full-wave loop. It also explains why grandpa’s “rabbit ears” antenna elements are so long and why older rooftop antennas you see driving through cities and suburbs are so large.
Antennas don’t have to be so large to receive high-band VHF channels 7 through 13, but they still take up space. A full wave at 180 MHz (Channel 7) measures 1.67 meters or about 5.5 feet, while at channel 13, those same dimensions are about 1.4 meters and 4.6 feet. That’s a lot of metal to have mounted on a wall, which is why so many antennas wound up on rooftops or in attics.
The task of designing an effective antenna becomes exponentially easier at UHF frequencies. A full wavelength at 545 MHz (Channel 26) is just half a meter, or around 22 inches. So a half-wave dipole antenna would measure 11 inches and an array of them connected in a phased pattern could easily fit inside an unobtrusive thin plastic housing. Indeed; many of the best-performing UHF antennas I’ve tested use that approach, including models from Mohu, Winegard, and Antennas Direct.
For that matter, antenna science is pretty old, and even these new designs are adaptations of tricks that were learned over six decades ago when UHF TV broadcasting first started. That’s why the vast majority of new indoor antennas you come across are intended for use on UHF channels: It’s easier to engineer improvements when the physical wavelengths of the antenna elements are small. (And who wants to mount a full-wave loop antenna for channel 6 on their indoor wall?)
This blue LED blinks when scanning channels and doubles as a pushbutton to select between the seven antenna patterns.
The power supply is a block that takes up room on power strips.
A.I. AND ANTENNAS
The SMARTenna+ isn’t the first antenna to have active electronics. I’ve tested prototypes of “smart” antennas several times since the DTV transition started, but very few of them actually came to market or sold well if they did. Channel Master’s approach is a bit different and incorporates a thin plastic panel design (as we’ve seen many times already) with active electronics that scan for TV channels and set up seven different possible antenna patterns for each channel.
The actual guts of this antenna were developed by Ethertronics and I saw a demo of the prototype at CES back in January. (The Las Vegas market has numerous UHF TV channels.) The antenna patterns are created by electrically adding, subtracting, and otherwise combining different antenna elements. Remember; the wavelengths of UHF signals are relatively small, so it isn’t difficult to create noticeable differences in reception by creating these patterns.
For my tests, I installed the SMARTenna+ on an upstairs wall in my office. I picked the corner of the room closest to the TV transmitter farm in Roxborough (Philadelphia), a path that is over 20 miles and a couple of hills distant. I then ran the antenna lead to the power adapter and another coaxial cable to my spectrum analyzer and onto my television to verify reception.
I looked at the received 8VSB waveforms and verified reception with a spectrum analyzer and TS Reader software.
When you first power up the SMARTenna+, it will perform a channel scan and create and memorize the various antenna patterns. A blinking blue LED confirms everything is at work, and after a few minutes, the scan is complete as indicated by a steady blue light. At this point, you perform a channel scan on your own TV (or set-top box) to find out what you can receive.
I’ll interrupt myself here to mention that, unless you live very close to a low-band or high-band VHF TV transmitter, you may not pick up ANY broadcasts in these two bands with the SMARTenna+. That was certainly the case at my location, and in fact I saw elevated spectral noise in the high VHF band that precluded my watching programs on channels 9 and 12. (Why this is a potential problem will be explained at the end of the review.)
Since the FCC spectrum auction concluded last year, there has been a wave of channel swapping, hopping, and even channels going dark nationwide. Formerly active stations on channels 29 and 35 in Philadelphia have gone off the air, with networks like NBC re-packing six (yes, SIX) broadcast minor channels into one physical channel, UHF 34, formerly WCAU. (Which itself is scheduled to move soon.)
Removing channels 38 through 51 meant that there were more broadcasters than remaining channels, so now we’re seeing “channel sharing” as stations divvy up the bits and hope their MPEG2 encoders can provide quality video. Even the powerhouse 5 megawatt broadcasts from Allentown station WFMZ on UHF 46 will have to relocate as the station will be sharing bits on VHF channel 9 with WBPH and the Lehigh Valley PBS station, WLVT (formerly on UHF 39).
Figure 1. The UHF TV spectrum as received by the SMARTenna+ using its 4th pattern.
Figure 1 shows the UHF spectrum as captured by the SMARTenna+ using pattern #4. This band used to be pretty crowded, but only eight RF carriers were receivable – channels 17, 26, 31, 32, 34, 39, 42, and 46 – and by the end of July, at least two of those (39 and 46) will go off the air. Most of these channels aren’t difficult to receive here, but I’ve never ben able to find one indoor antenna position that can reliably deliver CBS on channel 26, NBC on channel 34, and Fox on channel 42 simultaneously.
Suffice it to say that of all the available patterns, setting #4 (achieved by quickly pushing and releasing the blue LED button four times) consistently delivered the best results. I can now watch all three channels on my office TV without dropout, something I could not do previously with other UHF panel antennas. Figures 2a-b, 3a-b, 4a-b, and 5a-b show just how much the patterns improved for KYW-26, WPSG-32, WCAU-34, and WTXF-42. There’s definitely some magic at work here.
Figures 2a-b. KYW-26 using pattern #2….
…and optimized with pattern #4.
Figures 3a-b. ION-31 and WPSG-32 as received with pattern #1…
…and pattern 4. I still couldn’t pull in the ION signal, but WPSG-32 was rock-solid.
Figures 4a-b. WCAU-34 as received (intermittently) with pattern #1…
…and received reliably with pattern #4. The signal from WCAU dips, dives, and twists frequently, possibly because of towers swaying in the wind and trees in the reception path.
Figures 5a-b. WTXF-42 as received with pattern #2…
…and received reliably with pattern #4. I could never hold both WTXF and WCAU steady with one antenna position. Now, I can.
I also verified how reliable the reception was for each channel by monitoring the MPEG transport stream with TS Reader software. As long as I saw green bars and a low Bit Error Rate (BER) count, things were copasetic!
Now, the bad news. The SMARTenna+ isn’t going to help much (if at all) with VHF channel reception. And that’s not good news for viewers who live in markets where stations are giving up their UHF channels to move to VHF channels, like Allentown/Bethlehem/Easton where 38, 39, and 46 are shutting down.
The news gets even worse if stations are relocating to channels 2 – 6, particularly in urban areas where reception is challenged by high levels of man-made impulse noise such as switching power supplies, air conditioning and heating units, fluorescent lamp ballast, LED lamp power converters (yes, they can cause interference!), and even silly things like digital cameras and other home electronics.
Figure 6 shows the low-band VHF spectrum as received by the SMARTenna+. That little bump near 85 MHz is WPVI-6, which normally booms in here on my attic high-band VHF antenna (lots of transmitter power makes the difference) but is otherwise undetectable with the SMARTenna+.
Figure 6. This is what channels 2 through 6 look like with the SMARTenna+. That little hill near 85 MHz is WPVI-6 and not receivable, while you can see the top of KJWP-2 between 54 and 60 MHz, drowning in a sea of noise.
Figure 7. Some man-made source of energy raised the noise floor from -87 dBm to -7 dBm, essentially wiping out WBPH-9 and WHYY-12. You can see the tops of both RF carriers peeking above the “overcast” and neither was receivable.
It’s not any better on high-band VHF. You can see the 8VSB carriers poking out of the noise for WBPH-9 and WHYY-12 in Figure 7, but the elevated noise floor (10 dBm stronger than it is on UHF) makes reception of these stations impossible. A simple bow-tie antenna fares better, as do a pair of those ancient rabbit ears. (Grandpa is laughing away somewhere…)
CONCLUSION
The Channel Master SMARTenna+ really does work as long as you are primarily setting up to watch UHF TV channels. It solved an annoying multipath problem in an upstairs room and all I had to know to use it is the relative direction of the TV towers. Given that my location is 20+ miles out with some obstructions, I’d expect closer-in viewers to experience even better results. If you are close enough to a TV tower on a high-band VHF channel, you may also have some success with reception simply because the field strength of the signal is so high.
https://www.channelmaster.com/SMARTenna_Indoor_TV_Antenna_s/368.htm
MSRP: $89.00
Channel Master
2065 W. Obispo Avenue
Suite 102
Gilbert, Arizona USA 85233
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