Which Outdoor TV Antenna?

[k man]

Newbie to the forum here,

Trying to get my two kids through college- Mom and I don't watch much tv,
trying to cut expenses. Your help here is greatly appreciated.

I have tested a couple of antennas already, mohu leaf 50 indoor, and mohu air 60 outdoor. (The outdoor test was about 25' above ground). Both did a nice job picking up nearby stations, but neither could pick up our favorite which is ABC. TV tuner used for the test was the built in on our panasonic plasma viera which is about 7 years old.

I need some advice on which outdoor antenna I should install. I don't need a extra channels, just the major networks, especially ABC.



http://www.tvfool.com/?option=com_wr...e2cbfb4f97f5f1

[Jake V]

You have two possibilities for ABC, WGGB real channel 40 at 41 degrees on a compass and WTNH real channel 10 at 195 degrees. Since most of your stations are between 122 and 163 degrees, and it is likely that you pointed the flat side to about 140-150 degrees.

Neither the Mohu 60 nor the Mohu 50 Leaf antennas are designed for VHF, so it is not a surprise that if you aimed the flat side of either to about 140 degrees that you would not receive WTNH. The Mohu antennas are not the best at gathering signals. They do OK when the UHF signals are strong (and sometimes will pick up very strong VHF signals).

I see two starting possibilities:

1. Starting assumption is that you already mounted the MOHU on the roof and you can't or don't want to return it. The first thing I would try is to point the flat side to exactly 195 degrees and see if you can attempt to get WTNH. If not try pointing the flat side to WGGB, UHF 40 at 41 degrees. Your other locals are pretty strong and I think you might receive them just fine. At any rate, it's a very easy experiment to try. If you lose any of the the stations in green you can re-aim the flat panel antenna to about 140 degrees (back to where you have it now) and add a VHF antenna (described below), aiming it at WTNH at 195 degrees on a compass.

2. But if you've returned it all you have a number of new possibilities. I'd probably go with a two antenna solution, one for VHF (ABC-WTNH-10) and a UHF for everything else. For ABC you could go with Stellar Labs VHF-Hi HDTV 174 - 230MHz ($24.99 at that link but might be cheaper elsewhere) aimed to 182 degrees on a compass and something like the Stellar Labs HDTV 30 Mile Bowtie Television Antenna ($13.99 at the link) aimed to about 142 degrees on a compass. [I do not know their return policy).]

You can also go to your local Walmart and pick up an RCA ANT-751 and try it. I'd start by aiming it at 195 degrees and then move it slowly towards about 142 degrees to see how it works. If that doesn't get you ABC WTNH you can re-aim to 41 degrees to try for WGGB real channel 40 and then see if the rest come in (but this option has a lesser chance of success) But make sure you can return it (you can usually get it with a mast for under $50).

There are other possibilities but I think they would get the channels you want inexpensively.

An additional assumption is that you have clear line of sight in the directions of the signals (i.e., no buildings or trees). If you do, you may want to post a picture.

Others will post, so I'd wait a few days to see what recommendations they have before purchasing anything.

[Jake V]

PS: I just found your 2013 post at http://forum.tvfool.com/showthread.php?t=13245

If you are still at the same address the advice given there remains valid. I recommended antennas that should do the job but are cheaper. The recommendations given there are more elegant.

[rabbit73]

Welcome back, k man:

I see you are going to give ABC another try. Jake is right; you need to try some of the ideas suggested in your previous thread to improve your reception of ABC. I favor something like Jake's idea No. 2 for WTNH, because if you try for WGGB, it will be difficult to combine two UHF antennas without a custom combiner. Both are very weak, but WTNH is on VHF-High channel 10 so it will be easy to combine the two antennas with a UVSJ UHF/VHF combiner.

You shouldn't need a preamp for your first 5 UHF channels, it would probably be overloaded by WFSB.

The MCM 30-2475 or the higher gain 30-2476 would be a good choice for WTNH. They are inexpensive, have poor assembly instructions, but usually perform well.
http://www.mcmelectronics.com/produc...-2475-/30-2475
http://www.mcmelectronics.com/produc...-2476-/30-2476

The antenna should be aimed at 195 degrees magnetic with a compass (182 degrees true).

UVSJ
http://www.solidsignal.com/pview.asp?p=uvsj
http://mjsales.net/products/tru-spec...ant=1198505857

You have some strong local FM signals that might interfere with the reception of ABC and will need an FM filter. You could use the Antennas Direct FM filter, but I think a HLSJ, high and common ports, would give more rejection of WCCC-FM on 106.9 MHz.
http://www.fmfool.com/modeling/tmp/5...6/Radar-FM.png

https://www.antennasdirect.com/store...on_filter.html

the HLSJ blocks all signals below channel 7, including the FM band
http://www.solidsignal.com/pview.asp?p=zhlsj

       UHF Ant >
                \
                UVSJ > coax > grounding block > TV
                /                       
30-2476 > HLSJ >

Use high and common ports of HLSJ to pass VHF-High and block FM

The coax should be grounded with a grounding block to help reject FM interference.

If the antenna is outside, the coax shield should be grounded with a grounding block that is connected to the house electrical system ground with 10 gauge copper wire for electrical safety and to reject interference. For further compliance with the electrical code (NEC), the mast should also be grounded in a similar manner to drain any buildup of static charge which will tend to discourage a strike, but the system will not survive a direct strike.

[rabbit73]

You are on the fringe of coverage for WTNH:



your location is between the blue and weaker purple signal strength:

[rabbit73]

This is the WTNH terrain profile shown by tvfool:

http://www.tvfool.com/?option=com_wr...ALLTV%26n%3d12

This is the terrain profile using different software:

[rabbit73]

This what the 30-2476 looks like up in the air:







I suggest you tilt the front of the antenna up to catch the signal coming from the mountain ridge; try 15 degrees.

[rabbit73]

The terrain profile for WBBG is also difficult.

http://www.tvfool.com/?option=com_wr...ALLTV%26n%3d11



If you want to try it, I suggest an Antennas Direct 91XG or an HDB91X UHF antenna, also tilted up. This will be completely separate from your other UHF antenna, and aimed at 41 degrees magnetic.

[k man]

alright, I took Jake's advice, went to walmart, tried the rca 751. While I wasn't able to perform the test via rooftop, the ground level test failed to pick up wtnh and wggb.

regarding line of sight-(Tried to upload pictures here but could not), facing northeast (41 degrees) I have at least 150 yards of clear open space before a single line of trees come into play. I'd estimate those tree tops to be at a 5-10 degree upward angle.

Facing south (196 degrees), trees come into play at about 50 yards. Those tree tops are much higher and closer- tops are at 45 degree upward angle.

Given those two scenarios, what is my next step? Is my abc goose cooked?

[rabbit73]

Given those two scenarios, what is my next step? Is my abc goose cooked?

Your goose isn't cooked until you have made a fair test for WTNH with the 30-2476 up in the air and it doesn't work.

30-2476 > HLSJ > UVSJ > coax > grounding block > TV

Use the High and Common ports of the HLSJ to pass WTNH and block FM signals.

Use the Low and Common ports of the UVSJ to block the strong UHF signals for the test.

The coax must be grounded to keep the strong signals out that might interfere with WTNH.

The antenna should be tilted up at the front.

If WTHN is still too weak, you can try a CM7778 preamp.

2476 > HLSJ > UVSJ > 7778 > coax > grounding block > power inserter >TV

If you do anything different, the test is not valid.

[k man]

I just found another site that maps ota broadcasts. wtnh and wggb are not even listed as an option.

why would that be?

[ADTech]

Originally Posted by k man

I just found another site that maps ota broadcasts. wtnh and wggb are not even listed as an option.

why would that be?

Because antennaweb.org uses a far far more conservative and more coarse signal forecasting algorithm. Most experienced folks view it as pretty close to useless.

[Tigerbangs]

You don't live very far from me: I'm in Springfield, and lived in West Hartford for many years. WTNH is not the horror show that it appears to be: you can get it, probably with a Stellar Labs 30-2476 mounted on the roof and aimed due south of you.

All of the Hartford stations are very close, and don't requite much of an antenna to receive. I would suggest a small UHF antenna, like a Stellar Labs 30-2420 2 bay UHF antenna mounted atop the VHF antenna, combined with a UVSJ, and routed to your distribution system, or to one TV, if that is all you care to connect. Don't worry, you'll be fine!

[k man]

Have decided to go for ABC with the help of an installer. Two story home, roof is very steep (and I'm risk adverse).

Found an installer on google, Technician I spoke with on the phone seems confident and knowlegable, says he uses tv fool data and based on initial off site analysis of my location, ABC is probable.

Tech is coming out monday, service begins with signal measurement and analysis ($125). If I move forward with antenna installation, analysis fee gets waived, and work installation estimate would be between $400 and $600. He also stated the antennas he uses are not huge, usually around 3' in length.

3 questions:

what signal measurements (from abc) are minimal requirements for reliable signal?

Is 4-600 dollar reasonable?

Is a smaller antenna viable for abc?

thanks for all your help!

[rabbit73]

Your location presents some difficult problems to solve for reliable reception of ABC. Since the tech knows your area, I defer to his advice, but I will give you my thoughts.

Most of your signals are UHF and strong from about 163 degrees magnetic.

For ABC, you have two choices: WGGB from 41 degrees magnetic and WTNH from 195 degrees magnetic, both of which are about 50 dB weaker than your local channels.

I doubt that there is a one-antenna solution. I think it will take two antennas unless you are willing to tolerate the inconvenience of a rotator.

I previously picked WTNH because its antenna could be in another direction than the UHF antenna and easily combined with a UVSJ UHF/VHF combiner.

After looking at your post #9 again

regarding line of sight-(Tried to upload pictures here but could not), facing northeast (41 degrees) I have at least 150 yards of clear open space before a single line of trees come into play. I'd estimate those tree tops to be at a 5-10 degree upward angle.

Facing south (196 degrees), trees come into play at about 50 yards. Those tree tops are much higher and closer- tops are at 45 degree upward angle.

I think he will pick WGGB because the trees from the south by the Nepaug River will make reception of WTNH too difficult. I suggest the Solid Signal HDB91X with the front end tilted up.

However, this will create another problem for him: he will have to combine two UHF antennas aimed in different directions. Using a splitter in reverse as a combiner doesn't always work; a custom combiner might be needed.

An alternative would be two separate antenna systems with an A/B switch. Yet another alternative would be the main antenna to the antenna input of the TV and the ABC antenna to a separate tuner with its output connected to the aux input of the TV.

what signal measurements (from abc) are minimal requirements for reliable signal?

Most installers make measurements in dBmV. WGGB is listed as about -75 dBm which about -26 dBmV. That is too weak; my Sadelco DisplayMax800 signal level meter doesn't even read much below -20 dBmV for a single channel scan, but my Sadelco 719E will read lower.

I would like to see at least -10 dBmV coming out of the antenna for ABC, because OTA signals constantly vary in strength, especially 2Edge signals that are affected by atmospheric changes more than LOS signals.

You can add the antenna gain to the dBm signal power listed on the report. You can also add preamp gain, but a preamp can't be used for the strong signals because it will be overloaded and the tuner will also be overloaded.

Most tuners will drop out a signal below -85 dBm = -36 dBmV.

Here is a calibration chart I made for my Sony KDL32R400A that gives signal strength readings at the tuner. It will give you an idea of the relationship between dBm and dBmV:



These are the two meters I use. The Sadelco 719E is on the left; the Sadelco DisplayMax800 is on the right.



In the UK, CAI installers (Certified Aerial Installer) are required to measure not only signal strength but also signal quality as defined by the number of digital errors.

Here is a signal that was strong enough, but the tuner couldn't pick it up because it contained too many errors. The antenna was aimed in the wrong direction, and didn't pick up any direct signal, only reflections.



I set up an antenna across the street and got a good signal that the tuner picked up.

Is 4-600 dollar reasonable?

It is, IF he can give you reliable reception of ABC.

Is a smaller antenna viable for abc?

ABC is a lot weaker than your local channels. Weak signals need an antenna with more gain. Antennas with more gain are bigger, but UHF antennas are smaller than VHF antennas.

[rabbit73]

Another way of looking at signal strength is by Noise Margin (NM) as listed on your report. WFSB has a NM of 70.9 dB even before adding antenna gain, which puts it in the overload category.



Interpreting Noise Margin in the TV Fool Report
http://www.aa6g.org/DTV/Reception/tvfool_nm.html

ATSC Recommended Practice:
Receiver Performance Guidelines

Document A/74:2010, 7 April 2010

RECEIVER PERFORMANCE GUIDELINES

5.1 Sensitivity

A DTV receiver should achieve a bit error rate in the transport stream of no worse than 3x10E-6 (i.e., the FCC Advisory Committee on Advanced Television Service, ACATS, Threshold of Visibility, TOV) for input RF signal levels directly to the tuner from –83 dBm to –5 dBm for both the VHF and UHF bands.

5.2 Multi-Signal Overload

The DTV receiver should accommodate more than one undesired, high-level, NSTC or DTV signal at its input, received from transmission facilities that are in close proximity to one another. For purposes of this guideline, it should be assumed that multiple signals, each approaching –8 dBm, will exist at the input of the receiver.

I have attached two old CATV signal level charts that your installer might like copies of.

[rabbit73]

Originally Posted by k man

I just found another site that maps ota broadcasts. wtnh and wggb are not even listed as an option.

It is possible to generate a report similar to the tvfool report at rabbitears.info. This report gives signal power in dBm:



signal power in dBmV:

[k man]

So the installer came out and I ended up with a digitenna dt-xf amp20-1. Preamp mounted on mast, power injector in garage. Its pointed east north east- about 42 degrees. Trying to go south at first to get wtnh didn't work. WTNH showed a signal on the meter, but not on tv. the good news is he was able to get channel 40 and 22 from springfield which accomplished jeopardy and an abc affiliate in my lineup. The installer claims local stations are strong enough for signal to catch back of antenna, while pointing 42 degrees to capture springfield.

Installer did a great job plumbing wires and such, everything looks clean. He said he stands behind his work and would come back out to address any issues.

a couple of things here- 1. I now have a tivo, which is a 4 tuner box.
2. the other night during some mist/rain, channel 61 became pixelated?

3. would putting a small amp right in front of the tivo help?

[rabbit73]

It sounds like you got good installer that will stand behind his work.

He picked the one-antenna solution which avoided having to combine two antennas.

1. I now have a tivo, which is a 4 tuner box.

The TiVo tuners are sometimes not quite as good as some TV tuners, so there might be a problem with marginal channels. The TiVo does have a diagnostics screen that gives signal strength, SNR, and uncorrected errors to help you with problem channels.

2. the other night during some mist/rain, channel 61 became pixelated?

Since it is coming in the back of the antenna it would be one of your problem channels. The best reception is when an antenna is aimed directly at the transmitter. The diagnostics screen can help you with the minimum values for signal strength, SNR needs to be at least 16 dB, and uncorrected errors should be zero.

3. would putting a small amp right in front of the tivo help?

Maybe yes, maybe no; you would have to try it because you don't have a way to measure signal strength except with the TiVo. Maybe this one will help:
one output
http://www.channelmaster.com/Antenna..._p/cm-3410.htm
2-way
http://www.channelmaster.com/Antenna..._p/cm-3412.htm
4-way
http://www.channelmaster.com/Antenna..._p/cm-3414.htm

Your antenna already has a 20 dB preamp, but your antenna is aimed away from the strongest signals, which reduces the chance of overload.

http://www.skywalker.com/Products/Di..._DIGI2002.aspx

http://digitenna.com/files/DigiTenna%20DT-XF.pdf

[Tigerbangs]

Sorry, but this installer doesn't seem to get the concept of deep fringe reception. WTNH is a Hartford Market Station, and it should have been your first choice. Springfield is a much smaller market than Hartford, and won't offer you any Conn. News. The antenna that he brought to you has almost no VHF gain and was completely unsuitable for your installation. I also deem it unsuitable to attempt to pick up a strong station from the back of an antenna, as it risks the multipath problems that you experienced with WTIC.

You do not need a deep-fringe UHF antenna aimed at Springfield; you need a small UHF antenna aimed at the Farmington towers, and a large VHF yagi aimed at WTNH's transmitter in New Haven. If you like, because I am pretty close to you, I would be happy to design an antenna system for you, and have your installer put it up.

I don't climb ladders any longer because of diabetic neuropathy, but I can still provide good advice.