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I analyzed UHF 4-Bay (No Reflector) versions posted by babblin5 and MakeTV
versus CM-4221 & mclapp M4 (if remove Reflectors):
http://imageevent.com/holl_ands/4bay
UTube antennas are too small, esp. for reduced UHF Band...and have SWR problems...
Spacing between bowties needs to be much larger than 5-3/4 inches and whiskers
could be longer....

I also posted plans/analysis for 8-10+ dBi gain Zig-Zag antennas for HiVHF band that
I think are perhaps easier to build than the typical LPDA shown in post #1:
http://imageevent.com/holl_ands/zigzaglpa
 

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Sorry, babblin5's overly small 4-Bay is the worst of the the bunch, bays are too close together.
Ditto for Makezine TV's nearly identical version.

Ya should have gone with an mclapp SuperSized M4, optimized for the new UHF Band,
and has limited Hi-VHF Band (Ch7-13) coverage:
http://imageevent.com/holl_ands/4bay

BTW: ALL of these 4-Bay antennas are 300-ohm, so simply use the standard
300-to-75-ohm Transformer/Balun.
 

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Although two stacked GH4's isn't the best, you CAN purchase Antennacraft Super G1484 (Google it),
as well as a G1484, an individual non-stacked GH4. Side-by-side stacking adapter is also available:
http://www.jedsoft.org/fun/antennas/dtv/gh.html
http://www.digitalhome.ca/forum/showthread.php?t=95834

Q: Where's the Hi-VHF curves for vertically stacked GH4???
Super-4-Bay (M4 or Kosmic SuperQuad) w/o Reflector are surely better and perhaps also with Reflector???

I just ran a single GH4 with Reflector Rods: only 3.5 dBi Gain for Hi-VHF, EXCESSIVE SWR from 20 to 40.

Compare to Super-4-Bays with and w/o Reflector Screens. Kosmic SuperQuad available for purchase,
and M4/M8's come in a KIT--some assembly required:
http://imageevent.com/holl_ands/multibay/4bay
http://m4antenna.eastmasonvilleweather.com/Computer models/Computer models.html
 

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What a WASTE OF METAL....he SAYS it's a "DB-4", but Bowtie-Bowtie Separation is only 5.25-in with 7-in Whiskers, which is closer to the U-Tube "DEFECT" 4-Bay. A REAL DB-4 measures out as just under 8-in Separation with just over 6-in Whiskers:
http://imageevent.com/holl_ands/multibay/4bay
http://imageevent.com/holl_ands/multibay/4bayrefl
BOTH of these antennas are ill suited for the NEW UHF BAND, providing very low Gain on lower channels and Excessive SWR.

Note that the suggested design doesn't appear to even use the DB-4's Reflector....thereby throwing away 3 dB of Gain, which letting in Multipath and Noise from the rearward directions...

Since the Impedance is very low on lower channels and very high on higher channels, simply "shorting together" all four Antennas to a common Feedpoint will result in extremely low impedance on lower channels and MAYBE an acceptable SWR on the higher channels....but only modeling will reveal the actual performance... [PS: I'm not volunteering for this fool's errand.....]

HDTVPrimer 16-Bay and 32-Bay Antennas use a 2-Way and a 4-Way RF Splitter/Combiner respectively, thereby avoiding the interconnect Harness Hassle (NOT an easy process). AND they use the larger CM4228 Antennas, which come with a Horizontal Harness between each set of 4-Bays (such as it is). A pair of equal-length transmission lines (parallel wires) could then be used to interconnect the Vertically Stacked 8-Bays, as I have modeled and Optimized for several Vertically Stacked 4-Bays.

However, using an array of antennas actually DESIGNED for the NEW UHF Band, such as M4, FF4 or A-D DB-8e would be even better....
 

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Yes, the WallTenna is TOO SMALL to provide OPTIMUM performance in the NEW UHF Band (Ch14-51) and is also TOO SMALL to provide any more than minimal performance, with high SWR in the Hi-VHF Band. But the Quick&Easy Modifications I modeled bring it up to the performance of an M2 and within 1-2 dB of the performance of truly OPTIMIZED, FULL-SIZE Antennas, such as the H2 and the fol. RLH2 (two versions) of 2-Bay Bowties with Hi-VHF Resonator Loops:
http://imageevent.com/holl_ands/loops/hu2baylooprlh212x10norefl
http://imageevent.com/holl_ands/loops/uhfrlh2baybowtierectloopnorefl
And [20"Hx22"W] H2 with poor Hi-VHF SWR (WITHOUT the Hi-VHF Resonator Loop):
http://imageevent.com/holl_ands/multibay/uhf2bays/uhfh22baybowtienoreflector

But Walltenna is probably NO WORSE than most (all???) of the OTHER Antennas on the market that are TOO SMALL, e.g. Mohu Leaf, Winegard Flatwave and many other "Flat Panel" type Antennas. 4nec2 Model for Flatwave revealed UHF Raw Gain = 3-4 dBi with Good SWR and Hi-VHF Raw Gain = 2.5-2.8 dBi (with Excessive SWR)....about as "good" as a mis-tuned VHF-Rabbit-Ears+UHF-Loop....and significantly lower UHF Gain than Unmodified WallTenna:
http://imageevent.com/holl_ands/multibay/uhf2bays/hivhfuhf2baywalltennaenhancements



Adding an Optimized set of Reflector Rods increases Gain by about 3 dB:

 

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They all look like KLONES of A-D products....except for the one that looks like a Silver-Sensor 7-El LPDA plus a Swept Forward Dipole for Hi-VHF...WAY overpriced, esp. considering it doesn't include a Preamp. It if wasn't so expensive it would be a much needed replacement for the discontinued UN-Amplified HDTVa.

BTW: LTE Band in Europe (and elsewhere in world) starts at 800 MHz, whereas North America starts at 700 MHz.....so a Euro Spec Preamp with LTE Filter does NOTHING to suppress OUR LTE Band....
 

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Well...that isn't exactly what I said....I only commented re LTE Band differences...but since you brought it up....Optimizing an Antenna Design specifically for our 470-698 MHz Band (which will be shrinking yet again in the near future) allows for MORE GAIN on ALL Channels, esp. the Lower Channels where most Yagi Type Antennas lose a lot of Gain. DIY examples include various Grey-Hovermans, Mclapps's M4 4-Bay and my H2, H3, FF4 and FF6 Multi-Bay Bowtie and various other Antennas (e.g. Hourglass-Loop, QuadTrap-Loop, LPDAs, Yagis, et.al.)....with 4nec2 Analysis Results found at the link in my signature line below....

OTOH: There ARE some Euro Antenna Designs that were specifically designed to cover 698 MHz....and THEN rolls off....some are found here:
http://www.aerialsandtv.com/aerials.html
BTW: Check out some of the "Group B" Antennas, bearing in mind that 698 MHz falls within Euro Ch49:
http://www.aerialsandtv.com/gaincurves.html#Bgroups
 

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Is the 30 dB Gain for VHF or UHF Band??? That is VERY HIGH and would likely cause Overload/Desensitization problems for most users. Note that Overload Specs (e.g. DIN45004 or equivalent) are missing....

How much loss at 698 MHz??? How much Loss beginning at 730 MHz???

Focus Antennas APPEAR to be designed for OLD UHF Band (just like their OLD A-D and C-M counterparts), rather than being Re-Optimized for 470-698 MHz. How about some SPECS to back up your claim that they are designed for North American Market???
 

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No Noise Figure or Overload Specs....or Tests. Looking at the Circuit Board, is looks like the GAIN SWITCH simply inserts a 12 dB Attenuator PRIOR to the Amplifier....which would greatly degrade Noise Figure when Lower Gain is enabled. [I would have chosen 6 dB, rather than 12 dB Attenuator....better yet, use Variable Gain, Dual Gate MOSFET.]

FYI: To me it appears that INPUT is on the LEFT, goes through a series of VHF and UHF Full Band Filters to the FM FILTER SWITCH (FM Filter Circuitry just below) and then to the GAIN SWITCH, which Enables or Jumpers Across a Resistor. The signal then goes through an Amplifier (54-700 MHz, NOT separate VHF and UHF Amps) and hence to the OUTPUT on the RIGHT. DC Power from that same connector travels DOWN thru an Inductance Coil to an on-board Voltage Regulator chip and then a series of isolation/voltage reduction Resistors that feed the Amplifier directly above. Note that two of these feeds go through Coils to prevent shorting out the RF signals.

From the Spectrum Analyzer Displays, there is a GAIN SWITCH that selects either 18 dB or 30 dB (consistent with the +/- 2 dB Spec) for BOTH VHF and UHF....that would be VERY useful to prevent Overload. Note that the Preamp does NOT use separate VHF and UHF Sections...which would ALSO have helped to prevent Overload of UHF signals from the more problematic VHF/FM signals.

There ALSO is an FM TRAP SWITCH, which enables an FM Band Filter with about 20 dB Loss (22 dB on 108 MHz Marker Freq), but they have chosen to PASS Ch6, so there is only about 5-6 dB Loss on 88 MHz. Unfortunately not enough resolution to actually SEE the Frequency Response across the FM Band....

LTE Filter is indeed intended for North American TV Band, with only about 1 dB Loss on 700 MHz and about 28 dB Attenuation on 750 MHz with either Gain Selection.
 

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YUP, your Engineer is realizing that it only possible to slightly attenuate the CELLPHONE to TOWER signals on 704-716 MHz, cuz they're too close to Ch51 top band-edge (698 MHz), which should NOT be attenuated more than say 1 dB. The BEST that can be done with an LTE Filter is to get rid of the TOWER Broadcast signals on 734-746 MHz (and another higher band) in North America:
http://www.digitalhome.ca/forum/81-...ew-digital-services-tower-10.html#post2587202

Max Output Level: 118 dBuV
Need to ALSO specify TEST CONDITIONS, such as either per DIN45004 (A or B or C?) Test Procedures or whatever alternative test is used. Typically the reported OUTPUT voltage value is for either TWO EQUAL Strong Signals [or one x dB stronger than the other] while adjusting the input level so that the 3rd Order Intermod Frequency (for example 2F1-F2) is y dB [46 dB or 60 dB are typically used] below the Strongest Output Signal.
 

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I've seen numerous TVFool Reports [perhaps 1 in 5] where $28 Clear TV Key's Vertical Monopole Antenna mounted directly to DTV's Coax Connector would pick up STRONG, LOCAL Stations....some only need an "UNFOLDED PAPER CLIP ANTENNA"...which might even be BETTER than the Clear TV Key, as discussed below:
Watch broadcast TV FREE with Clear TV Key HD Digital Antenna | Clear TV? Key

BUT:

1) Although Clear TV Key Antenna may pick up Stations with either Circular [Vertical = Horizontal Power] or Elliptical Polarization [typically LESS Power in Vertical Component], it is VERTICALLY Polarized, while MOST DTV Stations [out of 1797 in RabbitEars Database] are ONLY Horizontally Polarized and will probably NOT be received unless significant De-Polarization occurs during SOME Reflections [unlikely in most cases]:
RabbitEars.Info [List of 159 Circularly Polarized DTV Stations]
RabbitEars.Info [List of 374 Elliptically Polarized DTV Stations]

2) It only provides 0 dBi Gain on SOME UHF Channels which is insufficient to pick up even moderate Range Stations,

3) With much less Gain and Excessive SWR on VHF Channels,

4) It's HIDDEN behind all of that conductive Metal in the DTV which acts as a Reflector, blocking signals from a very wide Angle [more than 180-deg]...although it provides some Gain Enhancement for Stations located on the Backside of the DTV.

==========================================================
Even an Inexpensive 1-Bay Bowtie would make a MUCH better UHF and even Hi-VHF Antenna for Strong, Local Station Reception of HORIZONTALLY Polarized Signals......although I know of several BETTER Bi-Directional [for signals from nearly ALL Directions] Indoor Antennas [incl. UHF-Loop + VHF-Rabbit-Ears]:
UHF Bowties - NO Reflector
https://www.summitsource.com/Steren...0-75-Ohm-Balun-Part-Petra-700-110-P10577.aspx
Product Reviews Archives - HDTVexpert
http://www.hdtvexpert.com/useful-gadgets-wall-mounted-indoor-dtv-antennas/
http://www.hdtvexpert.com/antennas-antennas-on-the-wallwho-has-the-best-reception-of-them-all

More INDOOR Antenna Comparison Tests are found here:
http://www.avsforum.com/forum/25-hd...hdtv-need-better-stronger-antenna-signal.html
 
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