Can a roof antenna pickup these signals?

[tegat]

I need some help in determining if a roof antenna will allow me to pickup the OTA TV signals. This is my signal report http://www.tvfool.com/?option=com_wr...cc49f2517f4de5. I would run the signal to 3 or 4 TVs.

Category 1: WRNN 48, WTBY 27, W42AE 42, W30AZ-D 30. I don't really care about. Although I would care about getting W42AE if I couldn't get WMHT below.
Category 2: WRGB 6, WNYT 12, WXXA 7, WTEN 26, WCWN 43, WMHT 34, WNYA 13. I would be satisfied with these. These all appear to be north of me so may be able to just point in that direction.
Category 3: WABC 7, WWOR 38, WCBS 33, WNET 13, WPIX 11, WNBC 28, WNYW 44. These I would really like to get instead of category 2 but I think they are out of range.

Winegard's antenna selector recommended the HD7084P and the HD8200U for my particular situation but didn't show me receiving any channels from category 3.

I know I probably won't be able to tell definitively until I actually put an antenna up there but in the experience of folks around here, are these signals workable for the stations I want to watch? Is picking up anything in category 3 even remotely possible? Are there better antennas out there for my situation than the Winegards? I'm willing to get additional equipment if needed.

To see what happens to signal strengths at other antenna heights please post 5 more with exact address and antenna heights of ,

1 foot antenna height.

5 feet antenna height.

40 feet antenna height.

60 feet antenna height.

100 feet antenna height.

[tegat]

Here they are

1ft http://www.tvfool.com/?option=com_wr...cc49844bba7d78
5ft http://www.tvfool.com/?option=com_wr...cc49a9b4bf9d2d
40ft http://www.tvfool.com/?option=com_wr...cc4980bc4a3f74
60ft http://www.tvfool.com/?option=com_wr...cc494981b61587
100ft http://www.tvfool.com/?option=com_wr...cc499fe4c633de

Ok , I recommend antenna height of no less then 40 feet above ground and closer to 60 feet above ground is better.

The reference point is WNYA-DT REAL VHF Digital channel 13 , virtual number (51.1) MyNetwork.

At 25 feet the NM(dB) signal strength is Minus -10.2 . Not good , however might provide reliable reception.

At 40 feet the NM(dB) signal strength is Minus -5.7 . A little better and will most likely provide reliable reception.

At 60 feet the NM(dB) signal strength is Plus 3.1 , better.
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WRNN UHF channel 48 Regional News Network and Multi cultural programing.

WTBY UHF channel 27 TBN.

Are Strong signal strengths and will be received through the back of the antenna.

And W30AZ UHF channel 30 Spanish language , will most likely be received at the back angle of the antenna.
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I recommend the Winegard HD7084P antenna with a Antennas Direct CPA-19 preamp , aimed at about 8 degree magnetic compass direction.
Here is how to aim antennas , http://www.kyes.com/antenna/pointing/pointing.html.

As always , the starting aim direction of a antenna is the --> starting aim direction of a antenna.

-->If required<--The antenna aim can be change and the antenna can be moved up and down or relocated to find the best reception.

Most Digital Tv's have a signal strength meter and some Digital Tv's also have a signal quality meter.
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Here are some Strong and Sturdy antenna mounts , http://www.ronard.com/909911.html , http://www.ronard.com/Tripods%200703/4712.html , http://www.ronard.com/34424560.html , http://www.ronard.com/ychim.html.

Buy the ronard antenna mounts at solidsignal by typing the word ronard in the solidsignal search box or buy from ronard.

Here is a , free standing no guy wires , light weight aluminum , lay over tower , do all antenna install and adjustments standing on the ground.
http://www.palcoelectronics.com/pe300.aspx.

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For 1 Tv connected use no splitter.

For 2 Tv's connected use a , HFS-2D , 2 way splitter.

For 3 Tv's connected use a , HFS-3D , 3 way splitter.

For 4 Tv's connected use a , HFS-4D , 4 way splitter.

Buy the HFS splitters at , http://www.solidsignal.com or http://www.hollandelectronics.com.

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As a test of reception of the Weak Digital Tv stations/channels to the , south - south west.
Aim the HD7084P antenna with the CPA-19 preamp at about 200 degree magnetic compass direction.

Scan for channels and see what is received.

Digital tuners can develop - Digital Glitches - I recommend doing Double Channel scans.
http://www.dtv.gov/rescan.html.

http://transition.fcc.gov/cgb/consumerfacts/rescan.pdf.

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As always , trees and tree leaves do a real fine job of reducing or blocking Digital Broadcast Tv reception and so do buildings and other obstructions including your own house.

It is best to install the antenna at a location that has the least amount to no amount of obstructions of any type or kind in the directions of reception including your own house.

The Digital Tv/s Must Channel Scan for the Broadcast Tv Channels , often named the 'Air Channels' or 'Antenna Channels' in the Tv setup menu because the Broadcast Tv transmissions travel through the air from the transmitting antenna to the receiving antenna.

DO NOT channel scan for cable tv channels.

[tegat]

Thanks for the feedback. Looks like I may have to do without WNYA since a tower in my backyard doesn't appeal to me. With one of those roof mounts I can get the antenna to about 30 ft off the ground. At that height WNYA has an NM of -8.8. The next weakest signal is WMHT at -5.3 which is probaby on the fringe. http://www.tvfool.com/?option=com_wr...cc49adff8a4444.

On a related note, looking at the HD7084P I see different gain values for each channel. So would I take the NM value from the report and add the channel specific dB gain to see what is the predicted signal that channel will come in at? Reference http://www.tvantenna.com/products/tv.../HD-7084P.html

I also see one page listing the gain as 14.6 dBi m.bestbuy.com/m/e/product/detail.jsp?skuId=4529592&pid=1218480929549.
I understand how to work with the single gain value but not sure how to interpret the channel gain numbers.

Also, if I ran the cable from the antenna to a say a 4-tuner network card installed in a PC does that eliminate the need for a preamp or does the tuner have the same effect on the signal as a splitter would? The cable run would be 30ft or less.

At tvfool and other sites that I visit , there is ongoing reports from users that tuners that are installed in computers are not the best for digital broadcast Tv reception.

And also Tivo has a ongoing poor reception situation.

It suspect that makers of computer installed tuners are more interested in the reception of cable Tv channels.

As often happens with this ongoing issue , users reports are that digital tuners in digital Tv's are much better with solid no problems reception.

Here are some stand alone tuners and dvr's that have Excellent Digital Broadcast Tv Reception.

And are easier to use , then computer programs and installing hardware and software in computers.

http://www.epvision.com.

http://www.channelmasterstore.com.

Here is Internet Streaming.

http://www.wdc.com/en/products/products.aspx?id=570.

http://www.roku.com.

http://www.vudu.com.

[GroundUrMast]

Winegard is good about offering gain and beam-width numbers. The single gain value offered by other manufacturers is ambiguous... it may be the peak gain, the average gain... but I doubt it's ever the minimum gain. (Expect the gain of any antenna to change with frequency. For example, most UHF antennas have better performance on the higher channels.)

If you have a weak signal and know the antenna gain at that frequency, you can use the simple math at the following link to estimate the results. http://forum.tvfool.com/showthread.php?t=109 (Thanks to @gonzo & @mtownsend for starting the thread.)

Re. PC-card and network attached tuners, my personal experience with the SiliconDust HDHR tuners has been that they work well, but the tuners in the newest TV's are slightly better at holding a lock on a marginal signal. I won't give up on my HDHR tuners though, I have yet to find a better option for recording OTA to disk. http://forum.tvfool.com/showthread.php?t=820

If your tuner card has a built in 4-way splitter, expect the same effect as an external 4-way splitter (7 to 8 dB insertion loss).

[tegat]

I think I followed all of that but what is this "Additional Low VHF Noise" or "NM (correction factor)" that you reference? One of the channels I want to pickup is low VHF (WRGB 24) but has an NM of 22.7. Two of them are Hi VHF (WXXA 7, WNYT 12) with an NM of -1.1 and -0.1 respectively.

[GroundUrMast]

Electrical equipment such as motors, automobile ignition systems, computers, appliances, etc. generate radio frequency noise in various amounts. The noise tends to be concentrated at frequencies in the range of VHF and lower frequencies. The result is, there is more man made noise/interference affecting the Low-VHF channels. The exact amount depends on how many sources there are and how close they are to the receiving antenna. In a rural setting, with underground power lines, the noise level will be lower than in a dense urban or suburban location with many cars, computers, motors and overhead power lines. Generally, the estimated noise in the L-VHF band runs between 10 and 20 dB. The lowest channels tend to be affected the most.

For a general discussion of Low-VHF reception, please see: http://forum.tvfool.com/showthread.php?t=2858