Posts Tagged ‘Antennas Direct’

Useful Gadgets: Mohu Sky Outdoor TV Antenna

Depending on which media outlets you follow, “cutting the cord” is a fast-growing phenomenon. Or maybe it isn’t. Or maybe it’s a short-term threat to the bottom line of pay TV. Or perhaps it’s a long-term threat.

We do know this: Pay TV subscription rates have increased astronomically in the past ten years. An increasing number of subscribers are bellyaching about paying for channels they don’t watch. Some have even gone so far as to “cut the cord” and drop pay TV channel packages altogether; opting for Internet streaming and in some cases, free over-the-air TV broadcasts.

If you live in a major TV market, chances are there are plenty of free OTA channels you can pull in. Since every television sold since 2006 must include a digital TV tuner for these broadcasts, all you need is some sort of antenna to receive those signals.

And you may be surprised by how many channels there are. If you live in the Los Angeles basin, there are no less than 27 different digital TV broadcast channels carrying over 130 minor (sub) channels of programming! That’s more than I have in my cable TV package, although I’ll grant that I wouldn’t watch many of them.

But at least I don’t have to pay for channels I don’t watch. And that’s the appeal of free OTA TV, combined with on-demand streaming of movies and TV shows from outlets such as Hulu, Amazon, Netflix, and Vudu. All you are paying for is a fast Internet connection.

Here's Mohu's Sky antenna, jury-rigged to a ten-foot mast and ready for testing.

Here’s Mohu’s Sky antenna, jury-rigged to a ten-foot mast and ready for testing.

REACH FOR THE SKY

In the past, I’ve tested a raft of indoor TV antennas from Mohu, Walltenna, Winegard, Antennas Direct, and Northvu. In my most recent test, I also included an indoor test of Mohu’s Sky amplified TV antenna ($169.99, available from Mohu, Amazon, and other online retailers). While it did a pretty good job, this product is intended for true outdoor use and won’t replace a flat, wall-mount antenna.

So, I freed up some time to set up the Sky on my rear deck and really cut it loose. The Sky resembles an “x” dipole, or a crossed dipole antenna. It’s housed in solid plastic and comes with a “J” arm support for and mounting plate for attaching to a roof or eave. The Sky measures 21” x 9” x 1” and is supplied with a 30-foot-long coaxial cable. There’s also an active amplifier inside the Sky, powered by an inline USB-style transformer that mounts at your TV.

You don’t have to use the supplied cable – you can use any cable you want, and I suggest sticking with a decent quality run of RG-6U cable from antenna to TV to keep signal attenuation to a minimum. The phantom power supply will work with really long cable runs (I tried it with 100’ of coax, no problem), and you can also mount the power supply in your basement or attic and split the incoming signal to feed two or more televisions.

Antennas Direct's ClearStream 1 came out of storage for the competition...

Antennas Direct’s ClearStream 1 came out of storage for the competition…

...as did the ClearStream 2, tested on this site a few years ago.

…as did the ClearStream 2, tested on this site a few years ago.

 

Channel Master's 4221 4-bay colinear UHF antenna uses 60-year-old technology - and still works like a charm.

Channel Master’s 4221 4-bay colinear UHF antenna uses 60-year-old technology – and still works like a charm.

For comparisons, I went into my “aluminum archive” and pulled out a ClearStream 1 (single loop antenna) and ClearStream 2 (dual loop antenna), both sold by Antennas Direct, and a Channel Master 4221 four-bay “x” dipole antenna. To level the playing field, I added an external “off brand” amplifier with the ClearStream and CM antennas. This amplifier has about the same gain figure (15 dB) as the Sky model. (You can’t use the Sky antenna without its amplifier switched on.)

THE TEST

For my tests, I procured a pair of 5’ steel masts from Radio Shack and supported them with a Winegard tripod mount, held in place by cinder blocks. The actual outdoor reception test was simple. I attached each antenna to the top of the 10’ mast and rotated it to aim south-southwest toward Philadelphia (position “A” in the results).

I scanned for active channels using my Hauppauge Aero-M USB DTV tuner stick, and for every channel I detected, I then scanned for Program and System Information Protocol (PSIP data). If I was able to read it and identify the channel, I looked at the actual MPEG transport stream using TS Reader (indicated dropped packets and transmission errors) and finally verified that I had 60 – 90 seconds of clean video and audio with no dropout.

Here's my test rig, with an AVCOM spectrum analyzer and Hauppauge Aero-M connected to my Toshiba latop for reception and measurements.

Here’s my test rig, with an AVCOM spectrum analyzer and Hauppauge Aero-M connected to my Toshiba latop for reception and measurements.

Although this housing is lettered just like the Mohu Bolt amplifier, it's actually a phantom power supply for the Sky's internal preamp.

Although this housing is lettered just like the Mohu Bolt amplifier, it’s actually a phantom power supply for the Sky’s internal preamp.

 

This process was repeated after I swung the antennas to the north-northwest, towards Allentown, PA. I expected that in some cases, I’d be able to receive stations from both markets regardless of the antenna position. That’s because these antennas are sold as somewhat omnidirectional or “non-directional.” The manufacturer expects you can install the antenna outdoors as high as practical, and you shouldn’t have to worry about its orientation (North? South? West?).

In reality, all of the antennas I tested are somewhat directional, as you’ll see from my tests. So I suggest picking up a small antenna rotor, which is easy to find at Radio Shack and other online stores. Rotors come in real handy if the TV stations in your market have towers scattered all around the city. (Pittsburgh and Atlanta come to mind here.)

I also took a look at the actual 8VSB carrier waveforms using an AVCOM PSA-2500C spectrum analyzer, mostly to see how much multipath “tilt” was present in the signal. I’ve included a few of those screen grabs here to show the relative signal strength of multiple TV transmitters in the UHF band as received by each antenna.

At my location, the pickings on VHF are slim. WPVI broadcasts a towering signal on channel 6 in Roxborough, PA, while WHYY has a potent carrier on channel 12. In Allentown, WBPH is a strong beacon on channel 9. And that’s about it – the rest of the stations are found on the UHF band.

Of that group, several stations usually stand out in my tests. WPHL is very strong on channel 17, as is KYW on channel 26. (I can receive KYW in my basement, and I’m 22 miles away from the transmitter!) WCAU is pretty reliable on channel 34, as is WLVT on channel 39. And WFMZ in Allentown is broadcasting with over one million watts ERP on channel 46, meaning I can usually pull them in with a paper clip.

I should point out here that the vast majority of indoor TV antennas work pretty well at UHF frequencies, but are electrically too small to pull in many high-band VHF channels. They just can’t approach resonance and have gain. The same thing applies to outdoor antennas – a solid performer at UHF frequencies may have little or no gain on high-band VHF channels.

Here's a spectral view of channels 6 through 13, as received through the Sky antenna.

Here’s a spectral view of channels 6 through 13, as received through the Sky antenna.

 

And here's how channels 6 through 13 look like as received with the ClearStream 1.

And here’s how channels 6 through 13 look like as received with the ClearStream 1. Note that WPVI’s signal on channel 6 (about 85 MHz) is not receivable on the CS-1, but comes in like gangbusters on the Sky (above).

That doesn’t mean you won’t be able to receive any VHF channels. If the signal strength is there, your smaller antenna may couple enough energy anyway to enable reception. But keep in mind that while a quarter-wavelength antenna for UHF reception might only be five inches long, a quarter-wave antenna for pulling in channel 7 needs to be about 16 inches long to achieve resonance.

The moral of the story is that all of the test antennas are physically the right size for pulling in UHF channels. They may not work quite as well for high-band (175 – 216 MHz) VHF channels, and I don’t expect they’d work at all with low-band (54 – 87 MHz) VHF reception. It all depends on the distance from your reception location to the transmitter.

THE RESULTS

Table 1 shows how all of the antennas fared. In the “A” position, the Sky gave a good accounting of itself, pulling in all three of the Philly and Allentown high-band VHF broadcasts. It also snagged seven of the ten strongest UHF stations coming from both markets. While Antennas Direct’s ClearStream 1 couldn’t find WPVI on channel 6 (that resonance thing, again), it did even better by pulling in the remaining two VHF signals and all ten of the UHF stations.

 

Table 1 - Results of the outdoor reception tests. Stations received successfully are indicated in green text.

Table 1 – Results of the outdoor reception tests. Stations received successfully are indicated in green text.

 

Oddly, the ClearStream 2 picked up one VHF channel, but dropped the UHF signal from WYBE-35, giving it a score of 3 VHF and 9 UHF channels. And the venerable Channel Master 4221 four-bay collinear antenna nearly matched it, missing only WYBE and WPVI-6. (Again, this antenna has no gain at lower frequencies.)

Turning the antennas northwest to favor Allentown (position “B”) really quieted things down. The playing field was almost level across all antennas with the Sky locating 2 VHF and 2 UHF stations, the ClearStream 1 digging out one additional UHF station, the Clear Stream 2 adding one more UHF station, and the 4221 spotting one VHF and three UHF stations.

Here's a spectral view of all UHF channels as received with the Sky antenna. Compare it to...

Here’s a spectral view of all UHF channels as received with the Sky antenna. Compare it to…

...all UHF channels received with the ClearStream 1...

…all UHF channels received with the ClearStream 1…

...all UHF channels as received with the ClearStream 2...

…all UHF channels as received with the ClearStream 2…

...and all UHF channels received using the Channel Master 4221.

…and all UHF channels received using the Channel Master 4221. All antennas were in position “A” for these readings.

CONCLUSION

Mohu’s Sky antenna is a strong performer. It did surprisingly well in my earlier indoor antenna tests, but it’s much happier in free space with plenty of oxygen flowing around it. The antenna does exhibit a directional characteristic, as did the three other antennas in this test. But it was able to handle both VHF and UHF signals with aplomb, although its UHF performance wasn’t quite as good as the ClearStream 1 and 2 loop antennas with external amplifiers.

 

Mohu Sky Outdoor VHF/UHF TV Antenna

MSRP: $169.99

Sold by Greenwave Scientific

www.gomohu.com

 

Also available from other online retailers.

Useful Gadgets: Indoor DTV Antennas – The Third Time’s The Charm

Earlier this year, I posted a couple of product reviews of indoor digital TV antennas. The first test, posted on April 6, concluded that there isn’t a heck of a lot of difference between a $5 bow tie and a $40 ‘flat’ antenna when it comes to VHF and UHF TV reception.

The second test, posted on May 29, gave one manufacturer a ‘do-over’ as their original product didn’t perform all that well and was judged to be defective. And that test also included a newcomer who didn’t make the original cut. (Believe it or not, both tests grew out of a more impromptu test in my house of a couple of panel antennas!)

Since the Round 2 results were posted, three things transpired. First, I became aware of yet another indoor DTV antenna, called the Clear Cast X1 and sold through Sunday newspaper inserts, magazines, and even on this Web site.

According to Clear Cast, “Advanced patent pending design of the X-1 digital antenna pulls in free over-the-air digital and HDTV broadcasts in your area so you can leave behind cable-only channels & expensive cable & satellite bills. Receive crystal clear digital picture on any digital TV in the house with NO monthly bill, easy install and setup plus NO waiting for the cable guy.” OK, I was intrigued enough to order one (they’re not cheap!)

Secondly, the PR firm that represents Antennas Direct – the company that shipped me a Clear Stream Micron XG for Round 2 testing – inquired why I hadn’t tested the accessory reflector with the antenna. (Simple: As Steve Martin used to say, “I forgot!”)

Finally, the Mohu Leaf Plus that self-destructed in Round 2 had been replaced and was ready for another go. (The amplifier failed, a problem Mohu was aware of and corrected in subsequent production.)

So it was clearly time for one last trek to Mountain Lakes, NJ to put all of the antennas from Round 1 and Round 2 through one more workout. I loaded up my spectrum analyzer, computer, several spools of coax, and a few splitters and headed out to put this test to bed once and for all.

THE TEST

For Rounds 1 and 2, I used the same window as the desk in front of it was unoccupied at the time. This time around, I opted for a slightly different location between two desks so that I wasn’t interfering with everyone’s work. Additionally; since the test position had now shifted by about six feet, I decided to re-test every antenna from Rounds 1 and 2 to be consistent and fair to all.

Here's what the test site looked like.

 

And here's the 'reference' bow tie antenna taped to the window.

I was assisted in my endeavor by John Turner, the owner and president of Turner Engineering and a long-time veteran of the broadcast systems integration world. Using AVCOM’s PSA-2500C spectrum analyzer, we positioned a $4.99 Radio Shack bow tie antenna (no longer available) for best reception of WNJM-51 (now known as “NJTV”) out of Montclair, NJ.

I also connected a Hauppauge Aero-M USB stick DTV received to pull in each station, in tandem with the TS Reader MPEG stream analyzer program to verify reliable reception (i.e. low bit rate errors). Each antenna under test fed the spectrum analyzer and Aero-M through a two-way splitter, and each antenna was placed in exactly the same spot on the east-facing window, using four pieces of masking tape as markers for alignment.

For each test, I scanned for channels using the Aero-M receiver. Next, I scanned each physical TV channel that was received with TS Reader to see how clean that stations’ MPEG stream was. Finally, I captured screen shots of the actual waveforms from each station I received. And if those three steps didn’t prove which antenna works the best, I don’t know what would!

THE RESULTS

For the record, here are all of the test antennas:

 

Radio Shack bow tie ($4.99, no longer offered, but you can find them on eBay)

Clear Cast X1 ($68 plus shipping)

Walltenna ($35 plus shipping)

Mohu Leaf ($38 plus shipping)

Mohu Leaf Plus ($75 plus shipping)*

Winegard FlatWave ($40, free shipping through August 31)

Antennas Direct ClearStream Micron XG ($100 plus shipping)*

* – amplified, or comes with optional amplifier

 

For my tests, I scanned for all New York City and New Jersey DTV stations within range of Turner Engineering. One local station (WMBC-18) was so strong that I essentially discounted it from my test results – it would have come in with a paper clip!

The Clear Cast X1 is definitely NOT worth $70. Let the buyer beware!

 

But other stations weren’t quite as strong. WABC-7 is a good test of high band VHF reception, inasmuch as every antenna in the test is supposed to pull in both VHF and UHF signals. WNJB-8 in the Watchung Hills of New Jersey is another good test of VHF reception.

For UHF signals, I checked out WNYE-24 (atop the Empire State Building), WNBC-28 (also on Empire and usually strong), WFME-29 (in West Orange, NJ), WFUT-30 (on Empire), WCBS-33 (Empire), WWOR-38 (Empire), and WNJM-51 (Montclair, NJ).

I didn’t expect the antennas to have much luck with WABC or WNJB, as they are too small to have much gain at VHF frequencies. The amplified antennas were a different story, though. If you are aggressively marketing indoor TV antennas for ‘all band’ reception, then you’d better deliver!

Table 1 shows how the unamplified antennas compared to each other. Satisfactory reception is indicated by glitch-free video streams for at least one minute and a ‘clean’ reading with TS Reader, while Table 2 shows how the amplified antennas (or amplified variations) compared.

Yes, you can actually attach the Micron XG to glass with masking tape! (The reflector was a tad more difficult to install...)

 

Note that the ClearStream Micron XG was tested three different ways –‘ bare bones’ with no amplifier or reflector in Table 1; with its amplifier switched to 15 dB mode in Table 2, and with the amplifier on and the accessory reflector attached in Table 2.

 

Antenna

WABC-7

WNJB-8

WNYE-24

WNBC-28

WFME-29

WFUT-30

WCBS-33

WWOR-38

WNJB-51

RS Bow Tie

Yes

No

Yes

Yes

Yes

Yes

Yes

No

Yes

CC X1

No

No

Yes

Yes

Yes

Yes

Yes

No

No

Walltenna

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

Mohu Leaf

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

FlatWave

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

Micron XG

No

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Table 1 – Unamplified antenna performance

 

Antenna

WABC-7

WNJB-8

WNYE-24

WNBC-28

WFME-29

WFUT-30

WCBS-33

WWOR-38

WNJB-51

Leaf Plus

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

Micron XG w/amp

No

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Micron XG w/amp and refl.

No

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Table 2 – Amplified antenna performance

 

Oddly enough, the Micron XG was the only unamplified antenna to pull in WWOR-38. But it was ‘tone deaf’ when it came to the two high band VHF stations. Neither version of the Mohu Leaf could snag WWOR-38, either.

As for the vaunted Clear Cast X1, it was unresponsive to any VHF channels and couldn’t hear local station WNJM-51. In contrast, the late, lamented Radio Shack bow tie worked exceptionally well on just about every UHF channel.

Bonus reception: WNJU-36, which is a tough signal to pull in at this indoor location, was successfully reeled in by the Micron XG with amplifier and reflector. So was WXTV-40, also pulled in with and without the accessory reflector.

THE CHARTS

I’ve included a few charts to show what the actual DTV received signals looked like on the AVCOM analyzer. You may be surprised to see how small the differences are between each antenna, and you will also note that the reflector didn’t improve reception at all on the Micron XG – in fact, it actually made things worse, probably due to all of the signal reflections and multipath at the test site.

As a reference, the actual signal levels shown are about 12 dB stronger at the displayed resolution bandwidth (300 kHz).

Here's what the RF spectrum looks like from channels 18 to 51, using the bow tie antenna.

 

And here's the same spectral view using the Clear Cast X1...

 

...using the ClearStream Micron XG...

 

...and using the Mohu Leaf (no amplifier).

 

Here's channel 51, the former WNJM, as received on the bow tie...

 

...and here's the same station on the Clear Cast X1. No improvement.

 

Winegard's FlatWave pulled in channel 51 more robustly...

 

...as did the Walltenna.

 

Finally, here are received waveforms for WNJU-36 and WWOR-38, using the ClearStream MIcron XG with the amplifier set to 15 dB, but minus the reflector...

 

...and here's what those same waveforms looked like AFTER I installed the reflector. Reception actually worsened, something I saw on numerous other UHF channels. Indoor DTV reception can be funny that way!

CONCLUSIONS

It’s hard to make much or an argument for spending very much money on an indoor DTV antenna when you see how well the lowly $5 bow tie design performed! This antenna design has been around since the 1950s and is just one of those things that can’t be improved on – unless you build an array of them. (‘X’-shaped colinear UHF antennas perform the same as the bow ties.) It’s just unfortunate that no mainstream electronics retailer sells these anymore. (Hey Radio Shack, are you listening?)

However, it’s easy to make the argument that the Clear Cast X1 is definitely not worth spending $70 on, especially since it was easily outperformed by the far less costly Leaf, Walltenna, and FlatWave antennas. Even the bow tie picked up six more stations than the X1 in my overall tests, two of them on VHF. I don’t know what’s inside the plastic housing, but I’d bet it is nothing more than a simple dipole, bow tie, or loop antenna (Clear Cast’s claims to having a ‘patent pending’ notwithstanding). Keep your wallets in your pockets!

Among the basic flat antennas, I still prefer the Leaf – it’s smaller and more esthetically pleasing than the Walltenna (which still  does a good job, better than the FlatWave) and it’s been a reliable performer everywhere I travel. The Leaf Plus is a bit pricey at $75, but the amplifier – while not as powerful as that on the ClearStream Micron XG – helps pull in marginal stations and doesn’t add much to the form factor.

As for the Micron XG, I had mixed feelings about it. It’s big and somewhat blocky, expensive, and based on my tests, you can’t depend on it for VHF reception in suburban locations, a chore the other ‘flat’ antennas handled without much difficulty. In its favor, the Micron XG did pull in WWOR, something no other antenna could do. (Maybe that outcome was just a fortuitous combination of antenna position and signal level?)

The Micron XG amplifier makes a big improvement, but I’d suggest running it no higher than 15 dB. The 20 dB setting creates too much noise and also degrades weak signals, as observed with the spectrum analyzer. The lower-gain 10 dB setting is also very handy in fringe urban areas where you don’t need tons of signal, but just need to boost the carrier-to-noise ratio (CNR) a bit.

And that reflector? It’s hardly worth bothering with, as it didn’t improve reception on any of the tested channels and in some cases degraded it. Those results were puzzling, because the reflector effectively converts the antenna pattern to something resembling a two-element yagi, which should have more gain as it becomes more directional. Maybe you’d have different results over a line-of-sight (LOS) path, but that’s hard to ensure when trying to grab DTV signals indoors.

In any case, you should be able to get a decent indoor DTV antenna for less than $50. Stay away from the amplified versions unless you live in a fringe urban or outer suburban area, where there are less likely to be out-of-band sources of overload and interference. Always place your antenna near a window and/or closest to the direction of the TV transmitter(s) for best results.

Good luck!

Made For Each Other

Today at the annual CEDIA Expo trade show in Indianapolis, Antennas Direct and TiVo announced a special promotion that bundles the former’s ClearStream 2 UHF figure-8 antenna with the latter’s TiVo Premiere. Individually, the two items would sell for about $200. But the package will retail for just $99 at Best Buy through October 2.

The press release quoted Richard Schneider, president of Antennas Direct, as saying, “Most consumers are still unaware that HDTV is free, and that TiVo DVRs contain a DTV tuner, allowing that free HDTV broadcast to be viewed and recorded. When paired with a digital antenna, TiVo is the multichannel provider of the 21st century, integrating broadband and over-the-air digital content at a fraction of the cost of cable.”

 

You have to wonder who is getting the better of this deal. It’s possible that TiVo has a pile of unsold Premieres sitting in their warehouse, and figures that this could be a way to clear out some of that stock. After all, TiVo makes its money off the per-month subscriber fees, although it’s hard to imagine someone who wants to cut costs agreeing to pay $9.95 per month to get program guide information and a dual DVR. (TiVo still offers a lifetime subscription for $299, which you’d hit in about 30 months at the current rate.)

 

Best Buy can’t be making a lot of money on the deal, either – not at $100 for that much hardware. That is, unless they are also offering some sort of antenna installation add-on package? As for Antennas Direct, there is a tremendous mark-up on antennas, so they can still make some nice pocket change on this package if they move enough product.

 

The interesting thing about this promotion is that it only runs through October 2nd. If I were in charge, I’d run it through the rest of the year, or at least as long as the NFL season lasts. We all know that football is a big driver of big screen TV purchases, and the possibility of being able to record two games at once is a strong incentive to pick up a TiVo.

 

If you live in an area where you can pick up more than one TV market, you could have a choice of several games to record – an even bigger incentive. I’m able to watch both New York City and Philadelphia HDTV broadcasts of CBS games, and if it wasn’t for the unfortunate co-channel assignment of infomercial TV channel WMCN to UHF 44 in south Jersey, I’d be able to get both Fox channels, too.

 

Given the current mental state of the FCC, free over-the-air HDTV needs all the promotion it can get. The press release claims that more than 46 million households use antennas to watch TV, an increase of about 10% from a year ago. That number needs to be a lot higher for true critical mass, but it’s a start. And my hat’s off to Antennas Direct, Best Buy, and TiVo for promoting something of real value to today’s financially-stressed consumers.