2 Edge diffraction and oddball antenna locations?

#1
I recently had a chance to go over this article and am still pondering pulling in NYC TV. It seems as though the author of this post was having similar difficulties and through some searching on his property, was able to find a good spot-mere inches from the ground! Does that mean that the mountains actually bent the signal at a steeper angle toward the ground? I figure it's worth shot in my case. In any event, just for kicks, here is a shot I took from the peak of my roof looking directly east toward NYC:



The peak of the roof is about 18' and I was holding the camera high as high as I could over my head, so this would be the view from about 25'. I would plan to mount the antenna at 30' (If the roof ends up being the best place) if not maybe a little higher. My plan is to go ahead and order the 91XG along with a portable digital TV, hook it up, and literally walk around the yard with it. It's not a spectrum analyzer, but I figure its worth a shot. Finally-yes, that is a small yagi you see two houses down pointed east. I still haven't gotten a chance to catch up with the folks that live there to ask if they are using that antenna and if so what they get with it. Given the fact that it's a small antenna, not mounted very high, and that their house probably sits a full 10-15' lower on the hillside than my house, if they're getting ANYTHING from NYC it should be a good sign right?
 
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dkreichen1968

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#2
That antenna looks like it's been there a long time. My guess would be that they aren't using it. Like the old 1950's VHF reflector dipoles that are on a lot of houses in downtown Denver.
 

MrPogi

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#3
My plan is to go ahead and order the 91XG along with a portable digital TV, hook it up, and literally walk around the yard with it.
I use something similar to "walk in" an antenna in difficult locations. Best part of the portable TV is, when the power goes out, I'm good to go.

Yes, it often happens that moving the antenna DOWN will be better for edge signals. I recall reading that post you linked. At my own house, I had my antenna in my attic and when pointed south, I picked up a distant station that I couldn't get when I mounted it on the roof about 10 feet higher. TVfool even reflects the difference, shuffling the results for my stations with weak edge signals (the ones I don't get anyway) depending on how high I put the antenna. I wouldn't trust TVfool to be that accurate, though, and still rely on the mobile rig to walk in the location.
 

Fringe Reception

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#6
Badfish,

I have a Haier battery-powered TV that I could use for antenna signal hunting but its tuner cannot be pre-set to any channel. This TV must scan for channels and a signal has to be detected or captured to appear in its memory. This would be very inconvenient to do and time consuming while "walking" an antenna on a roof.

If your tuner has the same limitation I suggest you take it to a location where you can receive the channels you are hunting for and perform a scan to collect the channels you want to try to receive at home, before you try it on your roof.

Jim
 

MrPogi

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#7
Badfish,

I have a Haier battery-powered TV that I could use for antenna signal hunting but its tuner cannot be pre-set to any channel. This TV must scan for channels and a signal has to be detected or captured to appear in its memory. This would be very inconvenient to do and time consuming while "walking" an antenna on a roof.

If your tuner has the same limitation I suggest you take it to a location where you can receive the channels you are hunting for and perform a scan to collect the channels you want to try to receive at home, before you try it on your roof.

Jim
Both my portables remember the channels found on the last scan. I get duplicates of nearly everything, and I delete the lowest signal duplicate on my home TV. On the portables, I leave everything I've ever scanned in the valley, and using only "add scan" when I do scan - because I never know where I'll be installing next.
 

Fringe Reception

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#8
Sadly, the Haier portables don't have an 'add' function which is especially annoying when using several different antennas or an antenna rotor, as a complete new scan is required to receive channels from different directions and rescanning wipes the existing saved channels. :eyes:
 
#9
That antenna looks like it's been there a long time. My guess would be that they aren't using it. Like the old 1950's VHF reflector dipoles that are on a lot of houses in downtown Denver.
True, but it begs the question, what DID it receive at one time? I guess part of the reason I've become so interested in OTA TV is that its a bit of a puzzle and a history lesson at the same time. I'm the type of person who is always interested in the inner workings of things and learning more about TV signals, where they originate from, how they work, etc...is fascinating to me. Wikipedia has been a good resource and from what I've learned, in the early days of NYC TV, transmission facilities bounced around from the Rockefeller Center building, to the Empire State Building, eventually to the World Trade Center in 1972, and back to the Empire State Building after 9/11. The interesting thing is that the antenna spire at 1 WTC was nearly 275' higher than the ESB spire. Since the development I live in was completed in the late 1960s (I'm pretty sure my home was first occupied in 1968) that antenna would have been receiving signals from 1 WTC. It makes me wonder if the loss of height, going from the WTC to the ESB has affected reception at all, especially for folks like me, nearly 50 miles from the tower. Of course, there is also the fact that the new Freedom Tower, slated for completion in 2013, will have an antenna spire as well. Conceivably NYC TV will return to 1 WTC and be broadcast from almost 325' higher than the current towers on top of the ESB-I wonder what effect that will have for folks on the fringe? In any event, it is a continuous source of curiosity to me as to why that antenna was ever there-it's not as if the difficult topography that is really the cause of the poor NYC reception out here has changed at all in the last 50 years-that ridge rose up about 17 million years ago at the end of the Precambrian Age :D

I have to say that you have a fairly clear view of the horizon from your roof. You may have a chance up there.
True-I never even thought to look until I was up there cleaning my chimney. Does it look like leaves on the trees will cause problems once they come in? I probably won't have the antenna up until Spring/Summer anyway, but just curious...
 

n2rj

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#10
True, but it begs the question, what DID it receive at one time?
Probably mostly VHF stations out of NYC which propagate further than UHF stations.

Prior to the digital transition, most stations that (English speaking) people cared about were on VHF - 2, 4, 5, 7, 9, 11, 13. Now most of those are on UHF. 2 is on ch 33, 4 is on ch 28, 5 is on ch 44, 9 is on ch 38. Only 7, 11 and 13 retained their VHF channels and WNJB moved to channel 8 because they couldn't stay on 58 (TV only goes from 2-51 now, and 14-16 are not available for use in NYC.)

VHF mostly fell out of favor for DTV because of noise issues. When there is lightning, VHF stations tend to break up when receiving them from a distance. High VHF is somewhat tolerable though which is why 7, 11 and 13 are there now. However, this may change as the FCC seeks to take the UHF spectrum for broadband and it will probably require cramming more stations down in the VHF range.

(There are a couple of low VHF stations as well, but these are not the big four/big six networks.)

The interesting thing is that the antenna spire at 1 WTC was nearly 275' higher than the ESB spire. Since the development I live in was completed in the late 1960s (I'm pretty sure my home was first occupied in 1968) that antenna would have been receiving signals from 1 WTC. It makes me wonder if the loss of height, going from the WTC to the ESB has affected reception at all, especially for folks like me, nearly 50 miles from the tower.
It definitely has but the DTV transition and shifting around of channels seems to have had an even bigger effect. The minimum requirement for DTV by the FCC was 95% of the original coverage.

Not all stations are there. Some, namely WNYE, WDVB, WASA and a couple others are at 4 times square (Conde nast building). WABC also has a backup transmitter there, IIRC.

Of course, there is also the fact that the new Freedom Tower, slated for completion in 2013, will have an antenna spire as well. Conceivably NYC TV will return to 1 WTC and be broadcast from almost 325' higher than the current towers on top of the ESB-I wonder what effect that will have for folks on the fringe?
I think they are staying at Empire for now, even when the FT is built. Bad economy, plus the ever looming threat of the FCC taking away spectrum. Besides, Empire is just fine, especially given that most people are receiving TV via cable, satellite or the phone company.

Antenna Plans Shorting Out At (Freedom Tower) 1 WTC: Gothamist
 
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dkreichen1968

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#13
That and apartments and condos make it difficult to put up one.
Yes, but landlords could add a lot of value to there properties for very little cost by installing MATV systems. Of course the concrete jungle of the inner city is a big problem, but there is enough population outside those areas, that can easily get good reception. It's primarily a mater of marketing.
 
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