Posts Tagged ‘Walltenna’

Once More, Back to the – Window??

Since I launched this Web site ten years ago, I’ve conducted numerous tests of outdoor and indoor TV antennas to see which ones really performed, and which ones were just “aluminum snake oil.” The problem with these tests is that, as soon as I complete one and write it up, I hear from yet another company who missed the boat and wants their time in the sun.

That’s the motivation for this round of tests, which included some previously-tested models and a few newcomers. It’s taken me a few months to schedule this test and round up all of the review models, but the good news is that every one of these antennas is currently offered for sale; some from multiple online retail outlets.

WHY INDOOR TV?

If you subscribe to pay TV services (as I do), you’ve surely noticed two things. (1) The monthly cost of your channel services has gone up over the past decade at a rate far in excess of ordinary inflation, and (2) you probably don’t watch more than 10 to 15 channels anyway on a regular basis.

Now, couple those observations with the expanding universe of Web-based (“over the top”) video channels, including the ever-popular YouTube, Hulu and Hulu Plus, Netflix, Vudu, Amazon Prime, and assorted network-based streaming sites. Add a Roku box, Apple TV, Boxee, or any of a number of OTT receiving solutions; drop the TV channel bundle from your pay TV subscription, and you’ve probably cut your monthly cost by 50%. (This assumes you’re keeping broadband service.)

Good thing I don't do this on a regular basis. They'd never get any work done!

Good thing for the gang at Turner Engineering that I don’t test indoor antennas on a regular basis. They’d never get any work done!

 

All well and good, except that streaming video services are very much dependent on available bandwidth. Watching Modern Family or The Avengers at 2 PM when Internet traffic is light is a completely different experience at 10 PM, when it seems that everyone and their brother is hogging bandwidth.

While there’s not much you or I can do about that problem (except perhaps subscribe to FiOS), you can watch HD broadcast network channels for free all over the U.S.A. And if you live near an urban area, you may have multiple channels you can pull in, using that little “F” connector on the back of your LCD or plasma flat screen.

 

The "mighty mite" - a Radio Shack $4 UHF bow tie.

The “mighty mite” – a Radio Shack $4 UHF bow tie.

NorthVu's NV20 Pro firmly attached (we hoped) to the window. Don't try this at home...

NorthVu’s NV20 Pro, firmly attached (we hoped) to the window. Don’t try this at home…

 

All you need to watch these channels is some sort of antenna. While outdoor antennas always work best, you may live in an apartment or condo where going that route is problematic for cosmetic or legal reasons (even though you do have the right to install an outdoor antenna on property that is yours exclusively, but I won’t get into that now).

The fact is; indoor TV reception has actually gotten easier and better. Yes, I remember the early days of digital TV reception, which involved more luck and prayer than anything else. But we’ve come way past those trial-and-error exercises, and it’s now much easier to pull in local digital TV signals indoors.

All you need is a TV antenna that meets the following criteria: It is resonant or close to resonant at the desired frequencies of reception; can be installed easily on a wall, window, or some other surface suitable for mounting, and is a true plug-and-play design. You just screw on the antenna cable to your TV, go into the appropriate set-up and channel menus, and scan for active channels.

 

It's a little bit easier to attach Winegard's FlatWave with masking tape...

It’s a little bit easier to attach Winegard’s FlatWave with masking tape…

...as it is to attach the Mohu Leaf. Maybe transparent tape would look nicer?

…as it is to attach the Mohu Leaf. Maybe transparent tape would look nicer?

 

ANYTHING GOOD ON TONIGHT?

If you haven’t tried indoor TV reception yet, you may be surprised just how many channels you can pull in. For many folks living in the Los Angeles basin who have a clear shot toward Mt. Wilson, that could mean as many as 27 major DTV channels with over 130 total sub-channels of programming. Heck, that’s a mini cable system into itself!

I live in the Philadelphia metro market, and can consistently receive 15 major DTV channels with over 30 sub-channels of programming. That’s using a modest dual-band yagi mounted at the base of my chimney, along with a similar antenna installed in my attic. And my dual-band UHF/VHF yagi antennas that sit atop a rotor and 5’ of mast on my roof can pull in another 8-10 DTV stations from New York City, which is about 65 miles distant.

These antenna systems supplement my Comcast cable service, which was cut off during Hurricane Sandy for the better part of a week by a 100-year-old oak tree that chopped the cable and telephone lines in half. Using an inverter (since replaced by a generator), I could still watch local news and weather from all of the locations just mentioned.

I’m a little too far away from the Philly TV towers in Roxborough to depend on indoor antennas, which is why I went the rooftop/attic route. But your location may be closer; in which case one of the models tested in this review could be right for you.

Here's the Leaf Ultimate with inline preamp (near bottom of photo) percolating nicely.

Here’s the Leaf Ultimate with inline preamp (near bottom of photo) percolating nicely.

Yes, we actually got a ClearStream Micron XG to stay attached to the test window! (Special formulation for the masking tape?)

Yes, we actually got a ClearStream Micron XG to stay attached to the test window! (Special formulation for the masking tape?)

 

As a general rule of thumb, homes and apartments as far away as ten miles from a TV station should be able to pull in the signal with an unamplified antenna. If the TV tower is located at a high altitude, as is the case in Los Angeles, Phoenix, Las Vegas, and Portland (mountains) and New York City and Chicago (skyscrapers), that indoor reception distance can increase by 50% or more.

However, there are locations where indoor DTV reception is borderline reliable or problematic. In those cases, an amplified antenna may be a better choice, as digital signals require a minimum threshold above background noise to be received correctly. For the ATSC system used in this country, the “laboratory” threshold is about 15 dB. In real life with signal echoes and fading, it’s more like 20 dB.

There are caveats with amplified antennas. First, not all amplifiers are created equal! Your particular amplifier may have lots of gain, but strong, nearby out-of-band signals can overload it and create more problems than it is fixing.

Second, amplifiers are noisy, and some more noisy than others. It does you no good to add an amplifier if it increases background noise (or as some call it, the noise floor) along with the signal. So a poorly-designed amplifier can actually make difficult TV reception worse.

Here's what the UHF TV spectrum looks like on the bow tie antenna...

Here’s what the UHF TV spectrum looks like on the bow tie antenna…

...and here's what it looks like on the NorthVu NV20 Pro.

…and here’s what it looks like on the NorthVu NV20 Pro. RF carriers from channels 18, 29, and 51 are anywhere from 3 dB to 9 dB weaker than on the bow tie, while channels 33 and 40 are barely there.

 

THE COMPETITORS – PASSIVE DIVISION

I selected nine different antennas for this latest round. Five were unamplified, and four had some sort of internal or external amplification. One of the amplified antennas (Mohu’s Sky) is actually intended for outdoor use, but I figured I’d see just how well it performed by a window anyway. (The Sky will be part of an outdoor antenna test soon.)

To kick things off, I needed a reference indoor antenna. What better choice than the classic UHF bow tie, which Radio Shack used to sell for all of $4.00? Although The Shack has since dropped this antenna from its catalog, you can still find them online. Summit Source has one made by Steren for all of $2.49.

Next up is the NorthVu NV20 Pro, a VHF/UHF panel antenna that claims to use a fractal-based design to improve resonance and performance. NorthVu is a Canadian company and its Web site promotes the use of free digital TV to cut costs of cable. A number of retailers carry it (including Amazon) and it will set you back about $60, plus shipping.

Batting in the #3 spot is the WallTenna, which I’ve tested previously. This flexible, super-flat antenna is intended for UHF reception only, although it might pull in VHF stations if the transmitter is close by.  At present, WallTenna is sold direct through the company’s Web site for $35.

Winegard’s FlatWave flexible panel antenna was another solid performer from previous tests, so it deserved another go-around. You can find it at numerous online sites and also in Costco, but prices are all over the place, ranging from $20 to $36. Shop carefully!

No test of indoor antennas would be complete without Greenwave Scientific’s Mohu Leaf, a strong performer in previous antenna tests. You can find it at numerous online and brick-and-mortar retailers (Sears, B&H, Amazon, Sam’s Club, J&R) for$40. You can also buy it direct from Greenwave.

 

Here's what WMBC-18 looks like with the WallTenna.

Here’s what WMBC-18 looks like with the WallTenna.

And here's what WMBC-18 looks like as received by the bow tie.

And here’s what WMBC-18 looks like as received by the bow tie. Not much difference!

 

WNJM-51, as received on the FlatWave antenna...

WNJM-51, as received on the FlatWave antenna…

...and the same station, as received by the NorthVu NV20 Pro.

…and the same station, as received by the NorthVu NV20 Pro.

 

THE COMPETITORS – AMPLIFIED DIVISION

Four more antennas rounded out the test, and all of them use active electronics to boost signal levels. NorthVu sent along the NV20 Pro Amplified, which looks exactly like the NV20 Pro except that it has a built-in power supply with AC cord. It’s currently selling for about $90, and Amazon has it.

Antennas Direct’s ClearStream Micron XG antenna is a panel design that comes in several flavors – (1) bare bones, (2) with a variable multi-step inline amplifier, (3) with a separate reflector panel, and (4) with both options together. Figure $80 for the basic panel with amplifier and $130 for the loaded system (which I tested). Oddly, the AT Web site currently lists a lower price for the basic panel antenna and amplifier ($79.99) than for the antenna alone ($89.99)!

The Mohu Leaf Ultimate is basically a Leaf antenna with an outboard preamplifier. Otherwise, it looks identical to the passive Leaf antennas, and you can find it at the same retail outlets for $90. (Sam’s Club had it for $55 at the time I wrote this.)

Finally, Mohu’s Leaf Sky antenna isn’t really an indoor design, but it’s small enough that I thought it would be fun to include it in this test. You may recall some of the bar-style VHF/UHF antennas that were popular a number of years back at the start of the digital TV transition: These could be installed on a roof or mounted on inside or outside walls. I figured it was worth seeing how well the Sky did on a very large window with minimal amounts of metal nearby to de-tune its pattern.

I think we reached the practical load limit for 1"-wide masking tape during this test!

I think we reached the practical load limit for 1″-wide masking tape during this test!

 

They may be hard to see, but there are two 8VSB carriers in there - WABC-7 (left) and WNJB-8 (right). There's just too much noise and not enough carrier-to-noise separation to pull in these signals with the ClearStream Micron XG.

They may be hard to see, but there are two 8VSB carriers in there – WABC-7 (left) and WNJB-8 (right). There’s just too much noise and not enough carrier-to-noise separation to pull in these signals with the ClearStream Micron.

The Leaf Ultimate couldn't do anything to help WABC's signal, but it did pull in WNJB-8 nicely (that hill just to the right of screen center).

The Leaf Ultimate couldn’t do anything to help WABC’s signal, but it did pull in WNJB-8 nicely (that hill just to the right of screen center).

THE TEST

For consistency, I decided to head back to the scene of my early DTV converter box and antenna tests – Turner Engineering, in Mountain Lakes, NJ. The Turner building is located on a bit of a rise with a decent view to the east, northeast, and southeast; good enough to pull in numerous DTV stations from the Empire State Building in New York City, as well as various DTV stations in northern New Jersey.

John Turner, president of the company and a life-long “tinkerer,” has always been a willing and eager accomplice in these tests, so we set up an area in his front office where we could attach each antenna to a window using copious amounts of masking tape (non-inductive!).

I was also able to find some space to set up the test gear, which included an AVCOM PSA-2500C spectrum analyzer, my Toshiba laptop, Hauppauge’s Aero-M USB stick DTV receiver, and Turner’s in-house DTV receiver system (a Samsung DTB-H260F ATSC set-top box, no longer available, and the legendary Princeton AF3.0HD 28-inch HD CRT monitor that was quite popular in the late 1990s.

The test was simple. After each antenna was attached to the window (not an easy task with some of the heavier models), I recorded the spectral views of various DTV channels from 7 (WABC-DT) through 51 (WNJM-DT). I also recorded wide views of the UHF TV spectrum from channels 14 through 51, and selected views of other high-band VHF DTV stations.

The final part of the test involved verifying reception without any dropouts or “hits” for at least 30 a minute. I also recorded MPEG transport streams from various stations to verify the bit error rate (BER) was indeed low.

If I didn’t see any hits and recorded a clean MPEG stream, the test antenna was rated OK for that channel. If the signal locked up even briefly or I saw too many dropped bits in the MPEG stream, it received an INT grade. If the station’s PSIP (Program and System Information Protocol) was detected by the Samsung and Hauppauge receivers, but the receiver couldn’t tune it in, the antenna received a NO grade for that channel.

 

Here's a view of the UHF TV spectrum as "seen" by the NorthVu NV20 Pro with amplifier.

Here’s a view of the UHF TV spectrum as “seen” by the NorthVu NV20 Pro with amplifier.

Here's a view of the same channels from the Leaf Ultimate.

Here’s a view of the same channels from the Leaf Ultimate. WNJM-51 (far right) is quite a bit stronger through the NV20 Pro, but the Leaf Ultimate is grabbing a much stronger signal from WMBC-18 (left).

 

THE RESULTS

Table 1 shows how each antenna fared for 11 different channels. One (WNJB) was on channel 8 in the Warren Hills of New Jersey, while the remaining ten channels  were all UHF and came from Empire and selected locations in New Jersey. The two strongest were WMBC-18 (Montclair NJ) and WNJM-51 (also Montclair), less than 11 miles away.

In addition to the channels listed, I also scanned for WABC-7 (previously received in tests at this location), WPIX-11, WNET-13, WNYE-25, and WNJU-36. However, none of the antennas were able to successfully pull in these stations aside from an intermittent signal here and there, so I dropped them from the test results.

The “No Amplifier” tests were surprisingly competitive, although I didn’t expect the cheapest antenna to be the best performer. But that’s how it played out as the UHF bow tie earned nine YES scores, one INT, and one NO. It was the only antenna to pull in WNYW’s signal on channel 44, a notoriously tough catch at this indoor location.

The WallTenna, Winegard’s FlatWave, and the Mohu Leaf all tied for second place with seven YES tallies, but the WallTenna and Leaf edged ahead by pulling in WNBC’s signal on channel 28 somewhat cleanly whereas the FlatWave couldn’t lock it up.

NorthVu’s NV20 Pro was the biggest disappointment in this test. It only garnered four YES scores against seven NO tallies. I would have expected a lot better, based on the preliminary specifications and information I received from NorthVu’s product management folks.

Table 1 - comparison of passive (top) and amplified (bottom) indoor antenna performance.

Table 1 – comparison of passive (top) and amplified (bottom) indoor antenna performance.

 

Intriguingly, the NV20 Pro is also about the same size as the late, lamented Kowatec CS102; one of the best indoor UHF antennas I’ve ever tested. (Hey, antenna manufacturers! Maybe one of you can scoop up the rights to the CS-102 and resurrect it?)

Things were a bit more exciting in the amplified antenna competition. Mohu clearly had the upper hand here with their Leaf Ultimate product, as it gathered up ten solid YES scores and a solitary INT (for WNYW, of course!) The new Sky product acquitted itself well as an indoor antenna, also bagging ten YES scores and a single NO (from guess who?).

The ClearStream Micron XG (without the reflector, which no other antenna offered or used) came in behind these two with seven YES and three NO tallies, plus a single INT from our friends on channel 44. Once again, NorthVu brought up the rear with their NV20 Pro Amplified, which fared only slightly better than the basic NV20. It scored five YES, three INT, and three NO tallies.

 

We checked for reception through all antennas using this vintage Princeton AF3.0HD CRT monitor. Remember CRT monitors?

We checked for reception through all antennas using this vintage Princeton AF3.0HD CRT monitor. Remember CRT monitors?

This is what the ClearStream Micron XG preamp looks like. Notice the four operating modes, selectable with a small tactile pushbutton.

This is what the ClearStream Micron XG preamp looks like. Notice the four operating modes, selectable with a small tactile pushbutton.

 

CONCLUSIONS

It says a lot that the least-expensive and simplest unamplified antenna design took on all comers and won. It also implies that the particular location where the antennas were mounted just seemed to favor the bow tie this time around (we didn’t test it with an amplifier). These tests were conducted in March with no foliage on nearby trees, whereas my last test was in late July of last year with trees fully leafed out. Even so, the bow tie did pull in WNYW-44 solid as a rock for as long as we chose to watch, something no other passive or amplified antenna could do.

All of the antennas performed equally well at the low end of the UHF band (channel 18) as they did at the high end (channel 51). Five of them were able to haul in channel 8 (about 180 MHz) reliably, which is an impressive feat for such small antennas that expect to work a lot better at UHF frequencies.

Ironically, only two amplified antennas could pull in WWOR on channel 38, something the bow tie did with relative ease. On channel 30 (WFUT), the NorthVu NV20 Pro was the only antenna that couldn’t hook up to the signal. A similar situation occurred with ION-31, not receivable on any of the passive antennas, but plenty strong with the Leaf Sky, Leaf Ultimate, and ClearStream Micron XG. Once again, the NV20 Pro Amplified just couldn’t pull it off.

I should mention that the ClearStream Micron XG’s preamplifier was set to a maximum of 15. Any higher, and the noise floor was degraded, something I could easily see on the spectrum analyzer. In general, I like to keep amplifiers at about 10 dB maximum to guard against this problem – too much gain creates all kinds of reception issues, and you only need to boost the signals up high enough to maintain the required carrier-to-noise ratio (CNR) for reliable digital TV reception.

The separate preamp supplied with Leaf’s Sky and Ultimate antennas is a good design, adding minimal noise while providing sufficient gain to pull signals out of the mud. I can’t say anything about the quality of the NV20 Pro’s amplifier as it is mounted internally, but in my tests it did not appear to add much noise to any of the received signals.

Based on these and previous tests, I’d give the WallTenna, FlatWave, and Leaf a thumbs-up. If you can find one, the bow tie is cheap enough to play around with and may fit the bill. (Hey, Starbucks coffee costs more and the thrill doesn’t last as long). I can’t recommend the NV20 Pro, though.

In the amplified crowd, the Leaf Ultimate and Sky both deliver solid performance. It is a testament to the design of the Sky that it worked so well indoors, but if you opt to use it this way, make sure you have a large window and keep it at least 2-3 feet away from any metal objects.

Antenna Direct’s ClearStream Micron XG is a decent performer, but expensive. I can tell you from a previous test that the reflector made little difference, but if that’s your cup of tea, position the antenna on a non-metallic surface (bookshelf, window ledge, etc.), aim it towards the TV transmitters when using the reflector assembly, and don’t run the preamp higher than the ‘15’ setting.

Most importantly, keep in mind that you don’t need to spend a lot of money to get reliable indoor TV reception. My best performers in the passive category were all under $50, and some were under $40. Check TV reception sites first (TVFool.com is one of the best) to get an idea of how strong signals may be at your location before you buy.

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!

Useful Gadgets: Wall-Mounted DTV Antennas Revisited

Last month, I tested a pile of wall-mounted indoor digital TV antennas to see if they really work as advertised.  Two of them (Mohu’s Leaf and the Walltenna) performed decently, while the amplified LeafPlus was a clear winner.

On the other hand, Winegard’s FlatWave was a disappointment, as it didn’t perform any better than a $4.00 Radio Shack bow tie antenna. That result led to a request from Winegard to return the review sample and see if it was defective.

It was, according to Winegard’s National Sales Manager, Grant Whipple. The culprit was (according to their email) “…a screw that was stripping and then causing a loss of contact between our circuit board and the antenna element itself.” Apparently this was an early production run issue.

Fair enough. Grant soon had a replacement back to me. Meanwhile, Scott Kolbe, who handles PR for Antennas Direct, sensed an opportunity and sent me a sample of their Micron XG indoor amplified TV antenna to test drive. The Micron XG isn’t a flexible, thin wall-mount design, but it is an indoor antenna and I decided to test it alongside the Winegard.

The Micron XG 'stuck' to the window. I never expected this to work -- but it did.

 

Here's what the Clearstream Micron XG amplifier looks like up close.

The tests, as before, were conducted at the offices of Turner Engineering in Mountain Lakes, NJ. I stopped by there after some RF interference testing in midtown New York City the Friday before Memorial Day weekend, and John Turner and I had the run of the place – everyone had gone home for the weekend.

To make things more interesting, I brought along the Mohu Leaf Plus, the original RS bow tie antenna, and my spectrum analyzer and digital camera.

THE TEST

John and I followed the same test procedure as we did in April. Each antenna was taped to the window with masking tape in the same position. A channel scan was performed with a DTV receiver (this time, it was Samsung’s DTB-H260F) and we verified dropout-free reception for 1 minute on each channel to qualify it as “received.” I also recorded the transport stream from each channel to check for bit error rates (BER) and recorded screen grabs of the actual waveforms for comparison among antennas.

Things started off again with the bow tie, which pulled in (unamplified) seven stations, all operating on UHF channels. The strongest local stations were WMBC-18 in Upper Montclair, NJ, and WNJM-51; also on the same tower. But the bow tie also snagged WNBC-28, WFUT-30, WPXN-31, and WXTV-40 from the Empire State Building, along with WFME-29 from West Orange, NJ. All seven stations were received reliably on the Samsung tuner.

Next up was the replacement Winegard FlatWave. After a channel scan, it also snagged seven stations including WNJB-8 (high band VHF!), WMBC-18, WNBC-28, WCBS-33, WXTV-40, and the 2nd minor channel from WNYW-44 (virtual channel 5-2). Of course, WNJM-51 also came in with no sweat.

 

Here's how WMBC-18 looked on the Winegard FlatWave antenna...

 

...and here's how the same station looked on the $4 Radio Shack bow tie antenna.

 

In essence, it was a draw between the $40 FlatWave and $4 bow tie. The FlatWave did pull in a high band VHF station, something the bow tie could not do reliably. But the bow tie snagged three UHF stations that the Flat Wave couldn’t reel in, one of which (WFME-29) was very strong on other antennas.

Just for kicks, I hooked up the original Mohu Leaf and let it do its thing. The result was nine reliable UHF channels, adding WNJU-36 and WWOR-38 to the previous lists. Catastrophe struck with the Leaf Plus, though – even though its power indicator LED was lit, absolutely ZERO signal passed through to the analyzer. It was cooked!

 

Here's what the UHF TV spectrum looks like with the amplified Micron XG...

 

...and here's how the same block of channels appeared with the amplified Mohu Leaf (not the Mohu Plus).

 

By itself, the Clear Stream Micron XG reached out and grabbed six UHF stations – WMBC-18, WNBC-28, WFME-29, WCBS-33, WXTV-40, and WNYW-44’s ’5-2’ service. WNJM-51 finished off the list. Not bad, but hardly an improvement over the bow tie. Adding the inline preamp netted three more UHF stations – WFUT-30, WPXN-31, and WCBS-33, putting the Micron XG on a par with Mohu’s basic Leaf. One caution – the in-line amplifier lets you kick in 5, 10, 15, or 20 dB of signal boost, but you need to use it sparingly – otherwise, you’ll ‘swamp’ your TV and create a lot of noise across the band.

Since the Micron XG preamp is a standalone product and works with its own power supply, we decided to have some fun and try it with the rest of the antennas. Hooked up to the bow tie, it delivered WNJB’s channel 8 beacon, plus WNYW-44’s ‘5-2’ service (whatever happened to 5-1?) and WWOR-38. Cool!

The FlatWave also benefited from additional amplification, pulling in ten different stations (WNYE-24 was the newcomer). But so did the Mohu Leaf, which snatched eleven different DTV stations, one of which was WNJB on highband VHF channel 8.  The table below summarizes the results for what are the nine strongest DTV station signals that could be received during the test. Each station’s call sign is followed by its physical channel.

 

THE RESULTS

A few solid conclusions came out of this re-test. First, the Mohu Leaf is still a formidable contender, amplified or otherwise.  Even though it doesn’t have much gain at highband VHF frequencies (channels 7-13), it also managed to pull in channel 8 with a boost from the Micron XG amplifier. (I’m still checking on what happened to the Leaf Plus.)

Second, I didn’t see much of a difference between the defective FlatWave and its replacement. True; the 2nd model fared somewhat better than its predecessor. But in terms of total stations, it didn’t do any better than the humble bow tie – it just substituted three different stations.

The Micron XG – which we actually wound up taping to the window for the test, using LOTs of masking tape – was a pretty weak performer without its accessory amplifier. However; with the amplifier, it was able to haul in three additional stations. But the Leaf did even better when amplified, capturing a test-high 11 stations reliably, one more than the FlatWave when it had a dance with the external amplifier.

Compiling the ‘yes’ and ‘no’ results into won-lost records, the Mohu Leaf finished in first place at 7-2 competing in the ‘no amplifier’ class, with a three-way tie at 6-3. In the ‘amplified’ division, the Leaf and FlatWave tied with 8-1 records, just head of the 7-2 Micron XG. (I didn’t list the amplified bow tie here, but it finished in 3rd place with a 6-3 log.)

How about performance vs. value? The Leaf is currently advertised on the Mohu Web site for $36, while the FlatWave is ticketed at $40. The ClearStream Micron XG will set you back $100 (the unamplified Micron A version is $60), while the humble bow tie is (gasp!) no longer listed on the Radio Shack Web site. (I guess it makes no sense to sell a $4 antenna when you can push a $20 Terk version that looks cooler.)

CONCLUSION

You don’t need to spend a ton of money to get decent DTV reception. In fact, you should be in good shape for no more than $40, based on my tests. If signal levels are really low, the amplified models will make a difference. Based on my tests, I’d suggest sticking with the Leaf Plus, as it is $25 cheaper than the Micron XG – and a lot easier to mount to a variety of surfaces, given how light and flexible it is.

And isn’t it amazing just how well a bare-bones antenna works? Higher cost doesn’t always equal higher performance. Caveat Emptor!

 

Useful Gadgets: Wall-Mounted Indoor DTV Antennas

A few months back, I ran a test of several indoor DTV antennas that you can mount on the wall, or on a window. Specifically, I looked at Mohu’s Leaf antenna and the Walltenna, and compared them to a baseline UHF table-top antenna and a $12 Radio Shack set of rabbit ears and a UHF loop.

 

Since then, I’ve received a few more samples to test against the Mohu and Walltenna. Mohu shipped me the amplified version of their Leaf (Leaf Plus, $74.99) while Winegard dropped off a sample of their FlatWave indoor antenna (FL5000, $39.99).

 

Well, nobody enjoys a good antenna test more than I do – except perhaps John Turner of Turner Engineering in Mountain Lakes, NJ, who offered to let me use his facility for these tests. So, I piled all of the flat antennas used in the December tests plus a Kowatec UHF panel antenna, a $3.99 Radio Shack bowtie, an AVCOM PSA-2500 spectrum analyzer, and a pile of coax jumpers into my car and headed north one fine day in late March.

 

At the test site, I was directed to use a large office window that faced east. A nearby desk provided a home base for the PSA-2500C and my laptop computer, which would simultaneously mirror the spectrum analyzer screen while running a Hauppauge Aero-M ATSC/MH USB stick receiver and the TS Reader MPEG stream analyzer program.

Here's the office window I used for the tests, with theKowatec panel antenna connected.

Here's the logging station, running WinTV7 and TS Reader for each antenna.

 

The methodology was to tape each antenna into the same position, connect 20’ of coax through a two-way splitter, and scan for channels while looking at each received DTV waveform. The TS Reader program would then confirm whether I was actually receiving a signal reliably, by providing me a read-out of the MPEG transport stream and the bit error rates (BER).

 

Speaking in plain English, this test was conducted as fairly as possible, favoring no antenna. I made no effort to try and ‘peak’ antennas for more reliable reception – I just taped them up and scanned away, just as the average consumer would do. Next; for every DTV station I supposedly ‘received’ on the Aero-M, I checked the quality of their signal before giving them a thumbs-up.

 

THE TESTS

 

Simple enough! Once each antenna was mounted to the wall (the Kowatec was attached to a tripod and placed in the same position as the other antennas), I performed a channel scan with the Aero-M, looking for both ATSC and ATSC MH (mobile) DTV signals.

 

After each scan was completed, I looked at each channel that was detected to see if a signal was actually present. (Sometimes ATSC receivers grab just enough PSIP data from an othwerwise weak signal to ‘capture’ it, which is why you have to verify reception.) If the signal played back reliably for several minutes with no drop-outs, I gave it a thumbs-up and moved on to the next detected channel.

For a measly $4, this bow tie antenna gave a very good account of itself.

Here's the Mohu Leaf doing its thing.

The Walltenna isn't easy to photograph against trees!

Winegard's FlatWave resembles the Leaf in appearance, but not in performance.

Here's the Leaf Plus, powered up and snatching signals.

 

After this process was completed, I then used TS Reader to see just how reliably each signal was coming through. TS Reader shows the accumulated number of dropped bits (BER) as you watch the program. The lower the BER, the more reliable the signal.

After compiling a list of stations received with all antennas, I then picked the seven that showed up repeatedly, whether received reliably or not. They were WABC (physical RF channel 7) from New York City, WNJB (physical channel ‘8’) in the Somerset hills in central New Jersey, WMBC (physical channel 18 from Montclair, NJ), WNBC (physical channel 28) from New York City, WWOR (physical channel 38) from New York City, WXTV (physical channel 40) from New York City, and WNJM (physical channel 51), also from Montclair, NJ.

 

According to the TVFool Web site, WMBC and WNJM are just 11.7 miles away from the Turner offices and are both ‘line of sight’ (LOS) paths, while WFME-29 (which didn’t come in reliably on any antenna save one) is a hair closer at 11.4 miles, LOS. WNJB sits 19.4 miles over a LOS path, while WWOR-38 in New York is 24.9 miles and also LOS.

 

WABC-7 and WXTV-40 were both shown as 1-Edge paths from the Empire State Building and also 24.9 miles away, while WNBC-28 was listed as a 2-Edge path (lots of multipath) from the same distance. So I had a nice mix of strong, ‘easy’ signals to go with some weaker, ‘tough’ signals.

 

Table 1 shows the results. A ‘yes’ indication means that the station was received without drop out for at least two minutes AND had a very low or almost zero bit error rate, as verified by TS Reader. A ‘no’ indication means either the station was not received at all, or was detected by PSIP but had too many dropouts to be reliable.

Table 1

 

Not surprisingly, the Kowatec antenna couldn’t pull in either high-band VHF stations 7 or 8. That’s because of simple physics: It has no gain at those frequencies, and its antenna array is too small to be of any use with channels 7 through 13.

 

I didn’t expect much from the Radio Shack bow tie, but it did OK by grabbing channels 8, 18, and 51. Not surprisingly, these are the three strongest signals at the Turner office location, so every other antenna should have pulled them in (which they did).

 

The Mohu Leaf gave a decent accounting of itself, grabbing channels 8, 18, 28 (one of the strongest UHF stations in New York City), 40 (also a powerful signal), and 51. The Walltenna equaled that performance with the same channels – no advantage here.

Here's the strongest local signal, WMBC-18, as received with the Radio Shack bow tie.

The Winegard FlatWave didn't pull in WMBC-18 any better than the bow tie.

Ironically, the now-discontinued Kowatec did a better job with channel 18 than any other non-powered antenna!

 

The FlatWave was a big disappointment, faring no better than the $3.99 bow tie – and it costs ten times as much! Most of the antennas in this test use variations on collinear antenna arrays, but aren’t electrically long enough to have any gain on channels 2-6 and 7-13. But the FlatWave didn’t even have that much gain at UHF frequencies.

 

I saved the Leaf Plus for last. Comparing an amplified antenna to non-amplified versions isn’t a fair test, and as expected, the Leaf Plus pulled in all of the listed stations reliably, except for WWOR-38.

 

However, it added WFME-29 (West Orange, NJ), WFUT-30 (Telefutura from New York), ION-30 (also New York), WCBS-33 (New York), and WNJU-36 (Telemundo, New York) to the list of ‘thumbs up’ stations.

 

Note that a few of these signals are listed as 2-Edge paths with much weaker signal levels on TVFool.com. So this antenna does perform very well, although a bit pricey at $75.

 

CONCLUSIONS

 

Reliable digital TV reception is all about having enough signal presented to the receiver so it can do its job. That also means high enough carrier-to-noise ratio (CNR) for the adaptive equalizer circuits to smooth out echoes and other signal reflections caused by multipath.

 

In general, any late-model TV built in the last four years has good-enough adaptive equalizer circuits to accomplish this task if it is presented with enough signal. For people who have problematic over-the-air DTV reception, low signal levels are usually the culprit. I’d suggest using the non-powered antennas if you live 15 miles or less from a DTV transmitter, and switching to an amplified antenna at greater distances. (Once you get much past 25 – 30 miles, you should really put up an outside antenna for best results.)

 

The Mohu Leaf and Walltenna work quite well for close-in DTV reception, while the Leaf Plus makes a big difference at longer distances. The FlatWave is a disappointment – save your money and go with the Leaf or Walltenna instead. Or, try a simple bow-tie or even Radio Shack’s 15-1882 VHF rabbit ears / UHF loop combo instead – for $12, you can hardly go wrong.

 

Ever wonder how much difference an RF amplifier makes? Here's a view of channels 18 through 51 at the test location, using the Mohu Leaf...

 

...and here's the same spectral view, this time using the Mohu Leaf Plus for reception.

Useful Gadgets: Super-Flat Indoor TV Antennas – Do They Really Work?

Depending on you believe, Americans are fed up with ever-increasing cable TV bills and are bailing out by the thousands on channel bundles, opting for free, over-the-air HDTV and movies and TV shows streamed over Internet connections.

 

Or maybe not.

 

While there’s no question that a cord-cutting movement does exist, it’s hard to tell how big that movement really is. But the allure of dropping $50, $60, $70, or more from your monthly Kabletown bill is strong, and the recent battles between Time Warner and MSG network over rights fees only serve to highlight the inflationary spiral of pay TV services.

 

If you live in a metropolitan area and have the major networks (CBS, ABC, FOX, and NBC), chances are you already have access to quite a bit of sports programming. Maybe not the 24/7 deluge from ESPN, but you do have NFL games through 2022, selected Major League Baseball games, the NBA Finals, the NCAA Final Four tournament, college football and basketball, and numerous golf and tennis tournaments. (Oh, and let’s not forget next summer’s London Olympics on NBC.)

 

And if you aren’t into sports, that’s all the more reason to stop paying for programming you don’t watch. There’s still plenty of good prime time programming available for free, not to mention reruns of older cable network shows (Curb Your Enthusiasm was available recently on UHF channel 17 in Philadelphia).

 

With that in mind, I recently tested a pair of flat TV antennas for indoor reception. The first is the MoHu Leaf antenna (http://www.gomohu.com/) ,available direct from MoHu for $39.95 plus shipping, and the second is the Walltenna (http://www.walltenna.com/) , sold by a company known as Urban Freedom LLC for $40 (also at online stores).

 

Figure 1. The Walltenna is transparent and flexible (and maybe not too attractive).

Figure 2. Mohu's Leaf antenna is also flexible, but opaque and a bit less inconspicious.

Both are marketed to cord-cutters. Both companies cite the trend away from pay TV services “…as more and more viewers look for higher value alternatives” and “…and to get free from recurring monthly cable or satellite bills, high-maintenance rooftop antennas, or bulky tabletop models.”

 

Do they work? I tested both recently for wall-mount and window DTV reception, alongside two other stalwarts – Kowatec’s UHF panel antenna  (discontinued) and Radio Shack’s model 15-1874 ‘budget’ TV antenna. Let’s see how they stack up.

 

THE TEST

 

My house isn’t in the best location for indoor DTV reception. Although it’s less than 25 miles from the Roxborough (Philadelphia) digital TV antenna farm, there is a slight hill and a bunch of tall trees in the way.  Only a couple of UHF stations (17, 26) and one VHF station (6) are strong enough to come through without separate amplification.

 

The back side of my house looks north towards Allentown, which has DTV stations on channels 9, 39, and 46. And they’re not all that strong, either. In short, I have the perfect location to test these flat antennas – weak signals, but just strong enough to lock up a tuner.

 

To quantify my tests, I looked at the received waveform for each DTV station on an AVCOM PSA-2500C spectrum analyzer. And I used Hauppauge’s WinTV Aero-M USB stick receiver to verify reception and get some screen grabs of the stations that came in reliably.

Figure 3. (clockwise from upper left) The Walltenna, Leaf, Kowatec, and RS 'budget' antennas in position.

THE CONTESTANTS

 

MoHu’s Leaf antenna looks mysterious and ‘stealthy’ with opaque black and white sides, but hold the black side at an angle to a bright light and you’ll see exactly what’s going on under that “luncheonette counter menu” plastic housing: A pair of dipole antennas with X-shaped capacity hats at the ends.

 

The Walltenna takes that design and makes it larger, except you can see exactly what’s embedded in the plastic – copper foil shaped much the same way as the Leaf antenna. It just doesn’t look as nice on the wall as the Leaf, but then again, some of the best antennas have little eye appeal. (In the eyes of us RF enthusiasts, however, they are things of beauty.)

 

The significant difference between both antennas – and one which I figured ahead of time would give the Walltenna the edge in receiving more DTV channels – is that the elements on the Walltenna are electrically longer than the Leaf. This means the antenna should be resonant at lower frequencies.

 

I should point out that neither antenna uses a traditional collinear dipole array, as many rooftop and wall-mount UHF antennas do. With a collinear design, the physical connection ‘crosses over’ from one dipole array to the next, so that each X-shaped dipole array is out of phase with the one behind and/or in front of it, creating a broadband response. In the case of the Leaf and Walltenna, the physical connection to each ‘X’ element remains on the same side of the antenna.

 

Both antennas are designed to be stuck to a window or fastened to a wall. Mohu doesn’t provide mounting holes, but Walltenna does. On the other hand, Mohu has encased the coaxial cable connection to the antenna in a solid plastic block, while Walltenna simply solders a balun to the copper strips and attaches the balun to the plastic cover with a rivet.

 

I do not like the latter method at all. First off, inserting a piece of metal between the balun legs at such close range de-tunes the balun lines. Secondly, the balun is stiff enough that it provides too much torque on the base of the antenna when bent – you must be careful not to put too much strain on the connector, and the supplied RG-6 cable jumper is too stiff and heavy for the balun.

 

Mohu’s antenna comes with a long run of mini 75-ohm coaxial cable. This cable has higher signal losses per foot, but is much lighter and more flexible for indoor installations. Given the rough handling that such antennas are likely to receive, this is a much better approach.

 

THE TEST: ROUND ONE

 

My first test took place in an upstairs bedroom. I removed an oil painting and hung/clipped the antennas to the picture hooks. For comparison, I elevated the Kowatec and Radio Shack antennas and placed them in the same position. This wall position is on the part of my house closest to Roxborough.

 

After scanning for channels, the Walltenna snagged a few expected stations and a few that were not. Channel 6 (WPVI) runs tons of power to overcome interference from nearby FM stations (Channel 6 is at 85 MHz, and the first strong FM channel in Philly is 88.5). So it wasn’t a surprise to lock up.

Figure 4. (Clockwise from upper left) Spectrum analyzer waveforms of WPVI-6 as received with the Walltenna, Leaf, RS 'budget,' and Kowatec antennas.

Figure 5. (Clockwise from upper left) WBPH-9 and WHYY-12 as received using the Walltenna, Leaf, RS 'budget,' and Kowatec antennas.

Neither was WHYY-12, which also runs beacoup power now that they don’t need to protect channel 12 in Binghamton, NY. WHYY locked up just fine without dropout. WBPH-9 from Allentown was also rock steady.

 

So were UHF stations WPHL-17 and KYW-26, also a couple of powerhouses. WCAU-34 was mostly reliable with the occasional ‘hit,’ as was WFMZ-46 from Allentown, another strong station. (WBPH-9 and WFMZ-46 antennas were on the wrong side of my house.)

Figure 6. (Clockwise from upper left) KYW-26 as receivedon the Walltenna, Leaf, RS 'budget,' and Kowatec antennas.

Figure 7. (Clockwise from upper left) WFMZ-46 as received on the Walltenna, Leaf, RS 'budget,' and Kowatec antennas.

I could see RF carriers from other stations, but none were strong enough to lock up the Aero-M tuner. Even so, this was impressive performance from a so-called “all band” omnidirectional antenna. What the designer got right was to make the antenna elements longer, which helps with gain at highband VHF frequencies (channels 7-13). But it can also degrade performance in the UHF spectrum – you never get something for nothing.

 

By using a balanced line connection to the balun, that problem is overcome. At higher frequencies, only the dipole elements are active. At lower frequencies, part of the transmission line becomes part of the antenna. It’s a technique I’ve used for years on ham radio antennas and on my ‘ugly duckling’ UHF antenna prototypes from a decade ago.

 

So, how’d the Leaf do? Not too bad, but it only pulled in channels 6, 12, 17, 26, and 46 reliably. Channel 9 was nowhere to be seen, while channel 34 suffered from constant breakup. Odd, considering the Leaf is primarily a UHF antenna design and WCAU’s signal on channel 34 is one of the stronger signals around.

 

The fact that the Leaf pulled in both channels 6 and 12 is a testament to how much power both stations run.  This antenna also uses a balanced line feeder to its coaxial connection, which provides resonance over a wider range of frequencies.

 

But the ‘X’ elements at the end of the balanced line are only 4.25” long, whereas the Walltenna ‘X’ elements are over 7” long.  So the Walltenna has a decided edge in reception of VHF signals.

 

How about the two ‘control’ antennas? Kowatec’s panel antenna is usually a strong performer with UHF TV stations, but all it could receive reliably in the test position was WBPH-9, WCAU-34, and WFMZ-69. Radio Shack’s ‘budget’ antenna (UHF loop and rabbit ears) did marginally better, pulling in WPVI-6, WHYY-12, KYW-26, and WFMZ-46.

 

THE TEST: ROUND TWO

 

For the next part of the test, I hung or placed each antenna in a back bedroom window, facing north towards the Allentown and Bethlehem stations. Once again, channel scans were run using the Aero-M and screen grabs were taken of actual DTV waveforms.

 

I didn’t expect to pull in much from this location, save for WBPH-9 and WFMZ-46. The Walltenna met those expectations and also pulled in KYW-26 as a bonus, off the side of the antenna. The Leaf antenna located the exact same stations with comparable reception results.

 

The control antennas provided mixed results, but one did marginally better. Kowatec’s panel antenna snagged WPVI-6, WBPH-9, and KYW-26 (no sign of WFMZ-46 and its million-watt ERP signal), while the Radio Shack 15-1874 delivered WPVI-6, WBPH-9, KYW-26, and WFMZ-46.

 

Obviously all of the antennas could have been placed more carefully for optimum results. But how many readers have access to a signal level meter, or a spectrum analyzer? I’m betting  not many. So my methodology of just picking an arbitrary antenna position yielded a fair set of results.

 

CONCLUSION

 

There’s definitely something to the Walltenna design, but it’s not black magic. Just make the elements bigger and you will approach resonance at lower frequencies. The X-shaped elements on the end act like capacity hats and do the trick! (A full wavelength @ 175 MHz – channel 7 – is 1.7 meters, while a full wavelength @ 665 MHz – channel 46 – is .45 meters.)

 

The Mohu Leaf is a solid performer on UHF and will pull in the odd VHF station, if it’s strong enough. Both antennas are easily concealed, but take care in what you place them behind or near, as metallic surfaces will detune each antenna and the balanced feed line, degrading performance. (Tip: If a metallic surface is placed ¼ wavelength behind each antenna at the desired frequency, it will become more directional on the opposite side.)

 

As for the control antennas, they held their own in at least one test, so I can’t say that either flat antenna had a distinct advantage over the Kowatec and Radio Shack entries. Where the flat antennas have the upper hand is in design – they’re easier to hide and to look at . (Although Walltenna should really take a page from Mohu and encase their product in an opaque plastic coating. )