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post #1 of 5 Old 05-04-2016, 06:36 AM - Thread Starter
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Question Boston, MA - Antenna results and next steps

Hello,
I am currently using the RCA ANT1450B hanging in the window of my attic facing East.
These are the stations I am getting today:
Code:
            Real    Virt    Azim    Pwr      Dist    
WJAR        50      10.1    143      -22.7    8.2    
WNAC-DT     12      64.1    138      -25.9    7.7    
WPRI-TV     13      12.1    138      -26.1    7.7    
WLNE-DT     49      6.1     143      -27.2    8.2    
WSBE-DT     21      36.1    143      -37.4    8.2    
WLWC        22      28.1    118      -61.7    26.7
According to TV Fool these are the stations I’d like to get but I’m assuming that my antenna just can’t reach them (I also live in a bit of a valley so this might not be real):
Code:
           Real    Virt    Azim    Pwr      Dist
WWDP-DT    10      46.1    79      -67      17.8
WGBH-DT    19      2.1     17      -70.8    25.3
WCVB-DT    20      5.1     17      -71.1    25.3
WBZ-TV     30              17      -73       25.3
WFXT-DT    31      25.1    20      -73.4    25.2
I’ve been searching for inexpensive antennas to try out in order to get there and ran across the ANTOP UHF-262. This one looks like it claims it has what I need but, I am dumb to all this stuff. I’m a little worried about it saying there is a beam width of 38’, I think I really want something closer to 120’. Does something like that exist without shelling out the money for a DB4? Is there a way to get any can get some confidence around this before buying?

http://www.tvfool.com/?option=com_wr...5134f3faa466d1

Thanks
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Devan

Last edited by Devanl; 05-04-2016 at 12:19 PM. Reason: Added TVFool link
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post #2 of 5 Old 05-04-2016, 07:16 AM
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Please post a link to your TV Fool report and not the image of the table. I'd like to click on the stations to see the terrain profile.

The stations you want but don't currently receive are all 2 edge. Here's how 2 edge reception works in most cases. The antenna needs to have line-of-sight to the edge that's closest to you. That means the antenna cannot be looking through trees, buildings, attics or even windows. If you can achieve that then chances are pretty good you can receive 2 edge signals.

Your two groups of stations are 120 degrees apart. You really need to be able to point to both groups. One antenna is not going to do it, especially when one group is 2 edge. The best you can hope for is to point at 17 degrees and hope that the multipath is low on your extremely strong LOS stations so that they can decode.
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post #3 of 5 Old 05-04-2016, 12:41 PM - Thread Starter
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@Calaveras , thanks for the feedback. I'm working on a mast outside but, I still haven't figured out grounding to the panel/meter on the other side of the house. Until then I was hoping to work out something in the attic window (maybe I could leave it open?) that I can move outside later.

I haven't really been able to discover a lot about successfully receiving a 2-edge signal. It sounds like there is a fair amount of scatter introduced, is there a way to recover from this (ie some form of antenna array)?

As far as the separation goes, what about something like the DB8e that offers aiming of multiple panels?

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post #4 of 5 Old 05-04-2016, 01:36 PM
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Quote:
Originally Posted by Devanl View Post
@Calaveras , thanks for the feedback. I'm working on a mast outside but, I still haven't figured out grounding to the panel/meter on the other side of the house. Until then I was hoping to work out something in the attic window (maybe I could leave it open?) that I can move outside later.

I haven't really been able to discover a lot about successfully receiving a 2-edge signal. It sounds like there is a fair amount of scatter introduced, is there a way to recover from this (ie some form of antenna array)?

As far as the separation goes, what about something like the DB8e that offers aiming of multiple panels?

There's a sticky at the top of this forum about grounding. Try that.

There has not been any discussion about scattered signals here that I can remember but I doubt you'd be able to receive such a signal with any antenna. The main thing is that the antenna must be LOS to the edge closest to you. No trees, buildings or any other obstructions. Every case that I've seen that has their antenna properly located can receive 2 edge signals. My 2 edge signals range from +5 to -11 dB Noise Margin (much weaker than yours) and receive all of them fine. I measured them at +22 dB to +37 dB Noise Margin and with all things considered, are 15 to 27 dB higher than predicted by TV Fool.

Attached is your terrain plot from TV Fool for WGBH. The antenna needs to see the 2 edge labels 2 in the plot.

Off pointing the panels on the DB8e is the same as using two antennas. Sometimes it works and sometimes it doesn't. My guess is that you'll have trouble with the 2 edge signals.
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Last edited by Calaveras; 05-04-2016 at 01:44 PM.
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post #5 of 5 Old 05-04-2016, 02:35 PM
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First of all, you must realize that those additional UHF stations are in a COMPLETELY DIFFERENT Direction than your Locals...and Ch10 towards a THIRD Direction....so you'll have to use a ROTATOR....or a set of THREE Antennas, each pointed in a different direction. You COULD try a simple 2-Way RF Splitter/Combiner for the two UHF Antennas, but might have problems with the OMNI RCA Flat Panel injecting Man-Made Noise and Multipath into the weak signals on the OTHER Antenna(s)....a higher Gain, narrower Beamwidth Antenna could HELP this situtation. If this is a problem [check each Antenna individually first], you will need to use SEPARATE Coax Downleads and an RF A/B Switch (you can still get R-S Remote Controlled RF A/B Switch on FleaBay).

ANTOP UHF-262 Specs says it provides 15.5 dB (dBd or dBi NOT stipulated and probably peaks well above OUR UHF Band), Front/Back Ratio = 25 dB and covers 470-862 MHz, so it is NOT Optimized for the (470-698 MHz) North American UHF TV Band....and although NOT specifically designed for Hi-VHF Band, will PROBABLY also receive Very Strong Ch12 and Ch13:
http://www.manualslib.com/manual/886...p-Uhf-262.html
Also offered under the Stellar Labs name, with SAME ambiguous Gain Spec:
http://www.mcmelectronics.com/produc...-2155-/30-2155

UHF-262 appears to be a KLONE of the old Televes DAT-43 (aka Triboom-46 in UK Aerials Report), which per fol. Gain Chart (in dBd, so add 2.15 for dBi) has a Gain of about 9.0 dBi on 470 MHz (US Ch14 ~ Euro Ch21), rising to about 12.7 dBi on 698 MHz (US Ch51 ~ Euro Ch49), eventually maxing out at about 15.2 dBi on 752 MHz (Old US Ch60 ~ Euro Ch52). So I'm going to guesstimate that ANTOP Max Gain Spec is 15.5 dBi (and NOT dBd)...uselessly stipulated for a MUCH higher Frequency than our UHF Band:
http://www.aerialsandtv.com/gaincurv...WidebandCurves

HOWEVER, my inexpensive Antenna of Choice would be the fol. Eagle 2-Bay Bowtie [buy TWO, they're cheap], which appears LARGE enough to provide performance "similar" to DIY M2 with a Screen Reflector (about 10-13 dBi):
http://imageevent.com/holl_ands/mult...bayrefl/m2refl
http://www.bestbuy.com/site/pro-bran...FReUfgodwsMEEw

If you decide to Build-Your-Own, my H2 with Reflector Rods is OPTIMIZED for our UHF Band and has sufficient Hi-VHF Gain and Multipath Rejection to also pick up Ch12 and Ch13:
http://imageevent.com/holl_ands/mult...baybowtievarrr


To receive Ch10, you are going to need a THIRD Antenna with significant Gain in the Hi-VHF Band pointed in a DIFFERENT DIRECTION....or a ROTATOR. You might want to consider whether that channel is worth the cost of adding the fol. Stellar Lab Hi-VHF 12-El Yagi, pointed towards 79-deg (re True North), using a VHF/UHF Combiner:
http://www.mcmelectronics.com/product/30-2476
They also offer a lower Gain, lower Cost 9-El Yagi:
http://www.mcmelectronics.com/product/30-2475

Whatever you try, be sure you can economically RETURN it.

The above is the bare-bones budget suggestion that is worth trying to receive those distance stations....and may or may NOT work....Attic Loss and Multipath is very difficult to predict, even from up close. BTW: for Attic use and NM's in the 20's, I would normally recommend a MUCH Higher Gain Antenna, such as DB-8e, CM4228HD (with HHH mod) or DIY FF4/FF6 [the latter three have significant Hi-VHF Gain but poor SWR]:
http://imageevent.com/holl_ands/mult...dblanglreflopt
http://imageevent.com/holl_ands/mult...6baybowtievdar
Of course, the DB-8e could initially be configured with panels pointed in different directions...or SAME if higher Gain is found to be needed...BUT bear in mind that the PCB Balun will significantly attenuate your Very Strong Ch12 and Ch13 [probably NOT a problem, but if it is, you COULD fix by replacing PCB Balun with conventional Transformer Balun].

Last edited by holl_ands; 05-04-2016 at 02:53 PM.
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