Trying to take my OTA experience to next level

[cflannagan]

My TV Fool Report: http://www.tvfool.com/?option=com_wr...e2cbfa8fc32d44

What's important to me: Clear reception for all the major TV networks: 8.1 (NBC), 10.1 (CBS), 13.1 (FOX), and 28.1 (ABC).

This is my first foray into using outdoors OTA antenna (previously, I've been using MOHU Leaf products).

Had professional installers do work around our house - adding ethernet jacks under TVs, burying cables (HDMI) behind wall, mounting our TVs on walls, etc. They also installed outdoors OTA antenna for me.

This was the first antenna I had installed:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Which is omnidirectional as you can see. I got the following:
8.1 (NBC) - seems solid, no pixelating at all
13.1 (Fox) - pixelating from time to time. But no loss of signal

Was not satisfied - wanted to get 10.1 (CBS) and 28.1 (ABC) as well, so I got a directional antenna instead:
http://www.solidsignal.com/pview.asp?p=hdb4x

I removed the first antenna (previously installed by professional) and replaced this with the new directional antenna by myself.

At first: I got all channels except for 8.1. So I worked to point my antenna toward the azimuth shown in the TV Fool report, and re-tested. I now had all major networks!

However - here are my current issues:
8.1 - this one seems to be the worst of all major networks. However, I am not quite sure what is happening. I can have solid signal for most of the day, only to suddenly have symptoms (pixellating a bit, or pixellating badly, or loss of signal completely). Sometimes those symptoms continue for hours, or only for a short time. I cannot figure out any pattern here. And it doesn't seem to be weather-related either, but I haven't confirmed this 100%.

The other channels - Fox 13.1 seems to fare better than 8.1, and the 10.1 (CBS), 28.1 (ABC) seems to be more solid. Which is odd because 8.1 seems to be the most solid when using the first antenna that I replaced (the omnidirectional antenna).

The antenna is currently roughly 8 feet off round, mounted on eastern edge of the house, pointed SE. There is house next to us to the east. Both our houses are 1-floor houses.

I am wondering if I will get significant results by rising my antenna maybe another 5 feet using "sweged mast" (basically extend my mast I have now by another 5 feet). Or if I should buy a different antenna that has more "wire" - like http://www.solidsignal.com/pview.asp?p=HDB8X maybe?

Does my setup have powered amplifier? Yes - still have that (it came with the first antenna, the omnidirectional one, and based on my tests, I need it - if I don't have powered amplifier, I cannot get 8.1 (NBC) at all).

Not sure about pre-amp - if this is important I can check (not sure how to check to see if I have one, but I have an idea of how I can check.. in the outdoor panel on the side of our house).

So should I consider extending my mast by 5 feet to hopefully make my 8.1 signal more solid? Looking to take my first outdoor OTA experience to the next level.

Thanks in advance!

[rabbit73]

Welcome to the forum, cflannagan:

The problem is the wrong antenna.

You need an antenna for VHF and UHF. None of the antennas you list are very good for VHF, in spite of what the marketing description says.

It is the REAL channel number that determines what antenna is needed, not the VIRTUAL channel number.

VHF-Low: real channels 2-6
VHF-High: real channels 7-13
UHF: real channels 14-51

The Omni antenna is not suitable for you. It works poorly in all directions, and its amp doesn't make up for its inherently poor performance.

You don't need an Omni antenna because your desired channels are all in the same direction.

The HDB4X and HDB8X are primarily UHF antennas, but they don't do very well for VHF.

You can add a VHF antenna to your HDB4X or replace it with a Winegard HD7694P.

I doubt that you will need a preamp if you have the correct antenna aimed at 122 degrees magnetic, unless there are trees or other buildings in the signal path.

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, but the system will not survive a direct strike.



Try it first without extending the mast to see how it does.

How long is the coax to the TV and how many TVs are you feeding?

If your TV has a signal strength indicator, it will tell you how weak a signal can be before you lose it.

[cflannagan]

Hmmm.. didn't realize about the UHF vs VHF performance in antennas - someone recommended the directional antenna (HDB4X) to me when I was having issues with the omnidirectional antenna; now it sounds like I might need to return not just 1 but 2 antennas :-D

The antenna feeds to 3 TVs in our house. The powered amplifier sits inside our garage attic, between the antenna and the splitter (going to 3 of our TVs). Not sure how long the coax is. Guesstimating maybe 10 to 20 yards from the antenna to the furthest TV in our house (our master bedroom)?

I also have a collection of 6 images I just took since your reply (thanks by the way).

http://imgur.com/a/ikzH5

For context:
1st photo is of our TV showing signal strength for 8.1. Just not too long ago, I observed the signal going out for 8.1 for a second, and when it came back, the signal strength was still showing 4 bars. Not sure what this means.

2nd photo is our antenna currently mounted up there.

3rd, 4th, and 5th photos shows what I think is grounding for the coaxial cable. I was able to trace the coaxial cable being grounded to the antenna itself.

last photo is meant to show the antenna more generally (zoomed out)

When you say "try it first" - try what first? I was wondering if you were referring to the grounding for the coaxial cable, or something else?

For the HD7694P, would I be able to mount it in that kind of mast I have up there right now? Looks like that "yagi-style antenna" is designed mainly for top of roof, which is not an option for me (not due to HOA, but not wanting to void the roof warranty by screwing something thru the rooftop - we recently had our roof replaced).

[wizwor]

Originally Posted by cflannagan

Hmmm.. didn't realize about the UHF vs VHF performance in antennas - someone recommended the directional antenna (HDB4X) to me when I was having issues with the omnidirectional antenna; now it sounds like I might need to return not just 1 but 2 antennas :-D

Frequency, gain, and beam width are the key characteristics of an antenna. Generally, antennas respond to UHF, VHF-HIGH, or VHF-LOW. All-in-one antennas are generally combinations of these. Given the narrow beam in which all your broadcasters reside, the fact that most are LOS (Line of sight), and the relative power of the signal coming in, you probably do not need to worry about gain all that much. I would try to make things work without any amplifier with a better antenna.

You really want to google each call sign in your list, check the wiki for sub-channels, and check titantv.com for programming. Make a list of the channels you want to receive. Group your list by frequency band (2-6, 7-13, 14+). Chances are Rabbit's suggested antenna will do just fine.

Originally Posted by cflannagan

The antenna feeds to 3 TVs in our house. The powered amplifier sits inside our garage attic, between the antenna and the splitter (going to 3 of our TVs). Not sure how long the coax is. Guesstimating maybe 10 to 20 yards from the antenna to the furthest TV in our house (our master bedroom)?

This will not make any difference as long as it's the right cable and your connectors are sound.

Originally Posted by cflannagan

When you say "try it first" - try what first? I was wondering if you were referring to the grounding for the coaxial cable, or something else?

Definitely ground first -- this is a safety issue -- but he was suggesting you try a new antenna with the current height before raising the antenna higher. Both the antenna/mast and the coax need to be grounded.

Originally Posted by cflannagan

For the HD7694P, would I be able to mount it in that kind of mast I have up there right now? Looks like that "yagi-style antenna" is designed mainly for top of roof, which is not an option for me (not due to HOA, but not wanting to void the roof warranty by screwing something thru the rooftop - we recently had our roof replaced).

That should be fine as long as the antenna is not too close to the roof. That roof is ceramic not metal, right?

[cflannagan]

Originally Posted by wizwor

Frequency, gain, and beam width are the key characteristics of an antenna. Generally, antennas respond to UHF, VHF-HIGH, or VHF-LOW. All-in-one antennas are generally combinations of these. Given the narrow beam in which all your broadcasters reside, the fact that most are LOS (Line of sight), and the relative power of the signal coming in, you probably do not need to worry about gain all that much. I would try to make things work without any amplifier with a better antenna.

You really want to google each call sign in your list, check the wiki for sub-channels, and check titantv.com for programming. Make a list of the channels you want to receive. Group your list by frequency band (2-6, 7-13, 14+). Chances are Rabbit's suggested antenna will do just fine.

That would be the virtual channels 8.1, 10.1, 13,1, and 28.1 (NBC, CBS, FOX, and ABC respectively). Looking the "real" channel numbers up for those, it looks like 7, 10, 12, and 29 respectively. So, looks like 3 in the 7-13 range, and 1 in 14+. Which makes it 3 in VHF-HI, 1 in UHF, I think (learning this as I go along).

Originally Posted by wizwor

That should be fine as long as the antenna is not too close to the roof. That roof is ceramic not metal, right?

Correct - ceramic titles (all houses in our neighborhood are required to have ceramic titles only, I know metal roofs would be problematic).

[wizwor]

We're talking next level, right? WMOR carries This TV which has retro programming and very good movies. WTTA carries My Network and Cozi. WTSP carries Antenna TV and Justice TV. If you are Greek, you may be interested in WZRA which would be a challenge to pull in with a single stationary antenna.

You should explore the other channels in case there is a special interest for you (heroes and icons is mine). If that channel happens to be on either flank, you will want to get an antenna with sufficient beam width to grab that station for you. H&I happens to be a sub channel of WTVT in Tampa -- which is on your list.

I think you are going to be surprised how high that next level is. Have fun!

[rabbit73]

Hmmm.. didn't realize about the UHF vs VHF performance in antennas - someone recommended the directional antenna (HDB4X) to me when I was having issues with the omnidirectional antenna; now it sounds like I might need to return not just 1 but 2 antennas :-D

The HDB4X is good for ABC, but not optimum other 3.

You only need two antennas if you want to keep the HDB4X UHF antenna for ABC, and add a second antenna for NBC, CBS, and Fox on VHF. If you want just one antenna for all four channels, you need a UHF/VHF combo antenna like the Winegard HD7694P or the RCA ANT751. The RCA has a smaller form factor, but it doesn't have as much gain which might be needed because of the trees I see to the SE.

The powered amplifier sits inside our garage attic,

Can you tell me the make, model and specs for it?

Thanks for the photos. The signal strength shown for 8.1 might be misleading if the amp is needed to compensate for the VHF deficiency of the antenna.

It looks like your UHF antenna is on a satellite mount. Hopefully your installer grounded the mount and grounded the coax with a grounding block. which is important in your area with so many storms.

When you say "try it first" - try what first? I was wondering if you were referring to the grounding for the coaxial cable, or something else?

I meant try a new antenna on the same mount before you add a 5 ft extension.

[rabbit73]

You can see the sub channels if you click on the callsigns in this list for your zip code.
http://www.rabbitears.info/search.ph...pe=dBm&height=

[cflannagan]

Originally Posted by wizwor

We're talking next level, right? WMOR carries This TV which has retro programming and very good movies. WTTA carries My Network and Cozi. WTSP carries Antenna TV and Justice TV. If you are Greek, you may be interested in WZRA which would be a challenge to pull in with a single stationary antenna.

You should explore the other channels in case there is a special interest for you (heroes and icons is mine). If that channel happens to be on either flank, you will want to get an antenna with sufficient beam width to grab that station for you. H&I happens to be a sub channel of WTVT in Tampa -- which is on your list.

I think you are going to be surprised how high that next level is. Have fun!

Yeah - those other channels are a bonus (looks like I'm getting those too with no issue). But ABC, NBC, Fox, and CBS for me is #1 priority - if I cannot get those channels without signal pixellating at times or going out completely, then I consider my experimental foray into OTA outdoor antennas a failed one (I sort of promised my wife we can live without the cable, lol.. I'm sure you have heard those stories before on this forum). But I know I haven't tried all avenues yet, which was why I came here. Glad to have found this forum and get help from you and others!

[rabbit73]

The powered amplifier sits inside our garage attic,

Can you tell me the make, model and specs for it?

[cflannagan]

Originally Posted by rabbit73

The HDB4X is good for ABC, but not optimum other 3.

You only need two antennas if you want to keep the HDB4X UHF antenna for ABC, and add a second antenna for NBC, CBS, and Fox on VHF. If you want just one antenna for all four channels, you need a UHF/VHF combo antenna like the Winegard HD7694P or the RCA ANT751. The RCA has a smaller form factor, but it doesn't have as much gain which might be needed because of the trees I see to the SE.

If I go this route - mounting a 2nd antenna - I will need to get additional mounting/mast hardware - not something I can piggyback/reuse the current mast I have now, correct? (Just making sure I understand what's involved)

Originally Posted by rabbit73

Can you tell me the make, model and specs for it?

Yup - it's the same powered amplifier that came with the omnidirectional antenna, which I left in place and am using it with the HDB4X. Seems to be getting better results with it than without.

https://images-na.ssl-images-amazon....SR970,300_.jpg

Originally Posted by rabbit73

Thanks for the photos. The signal strength shown for 8.1 might be misleading if the amp is needed to compensate for the VHF deficiency of the antenna.

Ah yeah - I took photo of the signal strength with powered amplifier in place.

Originally Posted by rabbit73

It looks like your UHF antenna is on a satellite mount. Hopefully your installer grounded the mount and grounded the coax with a grounding block. which is important in your area with so many storms.

Yup - I'm pretty sure it is grounded. I see what seems to be ground wiring going from the coaxial (that I can trace back to the antenna/mast), and the ground wiring going down the wall, into the ground.

I will try to get the antenna you suggested and try it to see if results improve. The problem is, it seems to be huge.. 6 feet long? Which means it'll be pretty visible from street. This would likely enter the territory where HOA would start sending me letters. So I might need to ask the installers to come back and move it to back of house if needed.

[rabbit73]

If I go this route - mounting a 2nd antenna - I will need to get additional mounting/mast hardware - not something I can piggyback/reuse the current mast I have now, correct? (Just making sure I understand what's involved)

Correct, no need to use two antennas if one combo antenna on the mount you have will do it.

[cflannagan]

I have purchased the antenna. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Hopefully this is the antenna! I see now why HDB4X fell short; it said it only had 15 mile range for VHF high band - no bueno.

For future reference, is there a website dedicated to listing the "truth" about each antenna - how well they would handle UHF, VHF-low, VHF-high, etc?

[rabbit73]

Yup - it's the same powered amplifier that came with the omnidirectional antenna, which I left in place and am using it with the HDB4X. Seems to be getting better results with it than without.

Thanks for the amp info. What I'm concerned about is overload; there is such a thing as too much amplification.

WMOR has a Noise Margin of 58.0 dB for an antenna mounted in the clear. If you add the HDB4X antenna gain of 12 dB (they say max of 14.2 dB) you are up to 70.0 dB NM, which is on the edge of overload.



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

Looking at it using the signal power, WMOR is -32.8 dBm.

-32.8 dBm + 12 dB ant gain + 20 dB amp gain = -0.8 dBm, which is tuner overload even when allowing for the coax loss after the amp.

It might be even worse than that, because the 1byone website says 32 dB gain, but they don't state the conditions:
https://www.1byone.com/TV-Accessorie...nna/OUS00-0683

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.

You have more than one high-level signal.

When you have partial overload, it is possible to receive your strongest signals, but the weaker signals (like NBC) become damaged by IMD (Intermodulation Distortion) which produces spurious signals which raise the noise floor and reduce the SNR of the weak signals to less than the minimum required 15 dB for reception. NBC is listed as 6.4 dB weaker than WMOR, but the difference is greater than that because your present antenna isn't very efficient for NBC.

The Winegard HD7694P antenna is 65 inches long, but the UHF corner reflector makes it look more massive.
http://www.winegard.com/kbase/uploads/HD7694P.pdf

I don't know the length the RCA ANT751, because RCA gives the box size, which isn't very helpful. If the RCA antenna is in the clear it SHOULD have enough gain, but the 7694 antenna has more gain if the signals are weakened by objects in the path.

[rabbit73]

Ah, I see you ordered the 7694.

I suggest you try it with just one TV and no splitter and no amp, to avoid tuner overload. Then, add the splitter. If the signals are too weak, replace the splitter with a Channel Master 3414 distribution amp.

For the HD7694P, would I be able to mount it in that kind of mast I have up there right now? Looks like that "yagi-style antenna" is designed mainly for top of roof, which is not an option for me (not due to HOA, but not wanting to void the roof warranty by screwing something thru the rooftop - we recently had our roof replaced).

I think that mount is strong enough for the 7694, but you should not add an extension because it does not have diagonal braces (which would require roof penetration). If you need to go higher, I suggest a mast on the side of the house from the ground up and braced by a wall bracket and a bracket where the base of the present mount is located.

The FCC says you can have your antenna as high as 12 feet above the peak of the roof no matter what the HOA says.
https://www.fcc.gov/media/over-air-r...n-devices-rule

[cflannagan]

Thanks for the very detailed post showing numbers. Lot for me to take (I'm a coder so I love geeky details).

So, based on your post, and studying other links/docs, I think I want to achieve a NM of 0 at least (preferably 5 or 10 NM, to give myself buffer, otherwise I'd probably have frustrating viewing experience having signal drop below threshold quite often due to random events).

Antennas comes with gain that will add to the NM (says here https://www.tvfool.com/index.php?opt...57#how_to_read that antenna is the only one that I can really add to NM?), and based on your post, it sounds like I don't want antennas with too much gain - because it seems most of the stations I want already have NM numbers of around 55? (adding 15 NM or so would put it into overload territory). How much gain would I get from the HD7694P?

And then signal power is another thing. Sounds like I want to aim for -5 dBm or less. Anything over -5 dBm would also be overload. So, if I remove the powered amplifier, it'll eliminate about 20 db, bringing me out of overload territory. Hope I understand this correctly.

But removing powered amplifier would cause me to lose NBC with my current antenna; we've already established that my current antenna is not effective for NBC, so the new antenna would most likely solve this.

Thanks for the quick education!

[cflannagan]

Originally Posted by rabbit73

Ah, I see you ordered the 7694.

I suggest you try it with just one TV and no splitter and no amp, to avoid tuner overload. Then, add the splitter. If the signals are too weak, replace the splitter with a Channel Master 3414 distribution amp.

Roger that. Thanks again!

[cflannagan]

Shoot, forgot to ask before I order. Does HD7694P have decent wind load numbers at least? Florida here, so we have storms.

[rabbit73]

For future reference, is there a website dedicated to listing the "truth" about each antenna - how well they would handle UHF, VHF-low, VHF-high, etc?

We are dedicated to telling the truth about antennas, because we want you to have good reception. If you don't, you will come back and tell us it didn't work.

We don't offer a guarantee, but we try very hard to give useful advice.

The antenna marketing departments have a tendency to make exaggerated claims to sell antennas and raise your hopes, which end up crashing on the rocks of reality.

Within each brand you can make a comparison, but not from brand to brand because sometimes gain figures are stated in dBi and sometimes dBd, with a difference of 2.1 dB. Mileage figures aren't too useful except within a brand. What good is a "50 mile" antenna if you are behind a hill that blocks the signals?

[cflannagan]

Originally Posted by rabbit73

We are dedicated to telling the truth about antennas, because we want you to have good reception. If you don't, you will come back and tell us it didn't work.

We don't offer a guarantee, but we try very hard to give useful advice.

Ha - if you remember details about each antenna - whether they're suited for UHF, VHF-HI, VHF-Low, without using a reference website, that's even more impressive :-D