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