antenna recommendation for Newburyport, MA

[bimr8]

Hello all,

I'm seeking an antenna recommendation of my new home in Newburyport, MA (see link for TV signal analysis results). I am seeking only to receive CBS, ABC, NBC, FOX and PBS. Will mount the antenna either on the roof or a gable end at about 25' off of the ground. Will point it in a fixed direction.

Total length of wiring is 88' and a splitter (for 2 TVs), OR 113' and a 3-way splitter (for 3 TVs). I don't need 3 TVs, but it'd be nice to have room for this potential upgrade in the future.

There was a recommendation of about 5 years ago in AVS Forum for a person in Newburyport to use a RCA ANT751R. I like the compact size of this antenna! Would this recommendation hold for me, or is there another recommendation? Also, would I need an amplifier on the system? Thanks much in advance for your help!

http://www.tvfool.com/?option=com_wr...8e031a6272fced

Bill

[rabbit73]

Hello, Bill:

The ANT751 doesn't have enough gain for your signals. NBC has a Noise Margin of only 8.7 dB. I suggest a larger antenna like the Winegard HD7697P aimed at 221 degrees magnetic by a real pocket compass and a Channel Master 7778 preamp.

The splitter goes after the power inserter. If you need more signal substitute a Channel Master 3414 amp for the splitter.

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.

[bimr8]

Rabbit73,

I sincerely appreciate your assistance. This forum is great for someone like me who is trying to get quickly get up to speed by picking brains.

I was a bit disappointed that I'd need an 11' antenna rather than a 3' antenna (I'll probably get over it! . I don't see a lot of antennas around here and hope to be somewhat inconspicuous as possible with what I put on the roof.

So now I'm wondering if the other post from Newburyport, MA was far off-base when they used (apparently successfully) an RCA ANT751R and no amp, or if they somehow simply lucked out. Here's the link: http://www.avsforum.com/forum/25-hdt...g-antenna.html Unfortunately the TVFool signal analysis is not included with the listing. I'm new to town, but don't believe that Newburyport has any substantial differences in elevation. Any explanation of the differences in our advice?

Thanks again!

Bill

[ADTech]

All of Boston's stations are UHF so, unless you're looking for something else, a UHF-only Yagi, 4-bay or 8-bay should do well, barring unknown signal impairments (trees, buildings, etc.

[rabbit73]

I will try to explain my thinking during my analysis of your situation.

It is the real channel number on your tvfool report that determines what antenna is needed.
VHF-Low, real channels 2-6
VHF-High, real channels 7-13
UHF, real channels 14-51

I suggested the 7697 in the event you wanted some VHF-High channels, real channels 7-13, later.

If size is important to you, and you limit yourself to the UHF channels, the antenna will be smaller.

(Ah yes, I see ADTech was posting while I was composing this TL;DR post.)

The 751 covers VHF-High and UHF, so the larger elements would not be needed for UHF only.

To meet your network requirements, this would be your line up with the antenna aimed at 221 degrees magnetic:

CBS, WBZ, CH 30, Noise Margin 17.8 dB
ABC, WCVB, CH 20, NM 18.8 dB
NBC, WHDH, CH 42, NM 8.7 dB
FOX, WFXT, CH 31, NM 16.0 dB
PBS, WGBH, CH 19, NM 19.0 dB (and maybe WGBX)

You are certainly welcome to try the 751. I'm the last person to discourage antenna experimentation. The 751 might be adequate for your strongest channels, but I think it is marginal for your weakest channel, NBC, with a 2Edge signal which means there is terrain interference for the signal on the way to your location.

I have learned the hard way that it is not a good idea to raise the hopes of a poster only to have them crash on the rocks of reality.

Perhaps this Noise Margin chart will help you understand NBC which has a Noise Margin of 8.7 dB putting it in the Weak category:



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

Looking at it from the standpoint of signal strength, WHGH has a signal power of -82.2 dBm. Most tuners will drop out a signal around -85 dBm, so you have too little "Fade Margin" because OTA signals constantly vary in strength, especially 2Edge signals. A larger antenna with more gain improves your Fade Margin for more consistent reception.

So now I'm wondering if the other post from Newburyport, MA was far off-base when they used (apparently successfully) an RCA ANT751R and no amp

I don't know if it was off-base or not because TVFOOL deletes old reports. I do know that in New England small changes in location can make significant differences in reports because of the terrain between the transmitter and the receiving location in spite of the local elevation.

The antennas you might consider are the Antennas Direct DB4E and the C4. The DB8E and 91XG would be more conspicuous against the skyline.

[bimr8]

Rabbit73 and ADTech,

You guys are educating me fast, I love it! Can you guess that I'm an engineer? I've now got plenty to study over the weekend before breaking the pending grip of the cable company. A quick peak at the recommended antennas indicate a variety of looks. I probably should also have stated that I am a little concerned about putting up a long directional antenna that would point nearly directly at a neighboring condo ... that might give them the heebie geebies in this day and age of NSA spying! Thanks again, and I will be reporting back when I get results.

Bill

[rabbit73]

I've now got plenty to study over the weekend

Glad we gave you some food for thought.

I am a little concerned about putting up a long directional antenna that would point nearly directly at a neighboring condo ...

Oh, OK, then you don't want the 91XG.

Is the condo in the signal path so that it might block the signals?

I don't have your exact address or coordinates, but to show you how different a report can be with a small change in location here are two estimates:

est1 based on your tvfool report, near Newburyport High School 42.8138,-70.887389
http://www.tvfool.com/?option=com_wr...8e03b8e09aaaf8

est2 based on zip, 42.812591,-70.877275 Strong St near US 1 Newburyport Turnpike
http://www.tvfool.com/?option=com_wr...8e03f6e9a2c465

and for comparison, this is your report:
http://www.tvfool.com/?option=com_wr...8e031a6272fced

[bimr8]

I've examined antenna mounting locations and suspect that the two possible locations might alter my antenna type. If I mount it on a gable vent at the back of my 2-story house/condo, then I'll be pointing directly at a nearby three-story neighboring condo (when aimed to pick up the Boston stations desired). The neighbor's condo wouldn't be all that much higher than the antenna height. Alternate location is a chimney along the side of the house in which case I'll be shooting through a couple of trees in adjacent yards.

Would this impact if I'm going the highly directional Yagi route or the somewhat square-ish bowtie antenna? Any idea which mounting location would be better? Thanks again!

Bill

[ADTech]

Any idea which mounting location would be better?

Have any options without trees or buildings in the way? Both will make any expectation or prediction of reliable reception not very likely.

[bimr8]

Unfortunately there's nowhere to put it without interference. It's either facing the nearby condo or nearby trees. The good thing is that it is not critical that we receive perfect television reception 24/7. It's only free television, I'll be happy with whatever I can receive most or much of the time! Thanks, Bill

[bimr8]

Just wanted to give an update on my TV reception after installing an 8-bay antenna about 30'-high aimed directly towards Boston, along with a pre-amp. My condo sits in a fairly low spot near the Merrimack River and the antenna shoots through a few trees. The antenna was installed by a firm out of southern NH that does many installations ... they recommended and installed the 8-bay Channel Master antenna and a pre-amp. I am receiving about 39 stations including ABC, CBS, NBC, PBS, and FOX. Channel 7.1 (NBC), the weakest station of interest to me, is being received mostly without pixilation, although pixilation occurs once every few minutes. The antenna installer says that reception of channel 7.1 would improve if the antenna were located 10' higher. The picture is otherwise beautiful!

Thanks for all your help and suggestions! I am satisfied, but may still raise the antenna height.

[rabbit73]

Thanks for the report of good reception. Glad we could help you.

[Tigerbangs]

How did you do with WSBK and WLVI?

[bimr8]

I've had a chance to check out several channels of particular interest to me, i.e. channels 25.1 (FOX), 4.1 (CBS), and 7.1 (NBC). I do get occasional pixelating with these channels. I do not get channels WSBK or WLVI at all. All the channels that I'm interested in are about 3 degrees of one another. I will be doing something about it. The antenna installer suggested raising the 8-bay antenna (with pre-amp) by a few feet, but I'm suspecting that I'd be much better off with a highly directional antenna. Your recommendations would be helpful again. Thanks!

[rabbit73]

Sorry to hear that you are having trouble.

The antenna was installed by a firm out of southern NH that does many installations ... they recommended and installed the 8-bay Channel Master antenna and a pre-amp.

The antenna that they installed is appropriate for your reception, if it is the CM4228HD. What is the model of the preamp?

The DB8e and the 91XG would also be suitable, but I'm not convinced they would do any better. If you want to take a gamble with no guarantee of improvement, try the 91XG up higher.

I don't think it is the wrong antenna; it's the wrong location for the antenna.

How is the reception when the antenna is connected to just one TV without splitting?

Can you show us some photos of what the antenna "sees" when aimed at 221 degrees magnetic?

Sometimes it isn't possible to improve reception beyond a certain point without heroic efforts.

[bimr8]

I've attached 3 photos. The 1st shows the antenna and its direction, the 2nd and 3rd show what it's aiming towards, unfortunately the camera shots have been taken at ground level and it's hard to get a good long-view. There's light tree vegetation in adjacent yards and a condo a bit off to the side of where the antenna has been aimed. I believe that I am somewhat in the low part of a valley.

I wasn't told the model of the 8-day Channel Master antenna, but the pre-amp is a Radio Shack antenna-mounted high-gain signal amp, model 15-321.

Raising the antenna height by a few feet will cost an estimated $110-160 parts and labor. I suppose I ought to just do it and be satisfied with what I've got unless there are other recommendations. Thank you!

[rabbit73]

Thanks for the photos. I would like to give you an idea that would guarantee an improvement, but I can only suggest things that might help:
1. Raise the antenna
2. Try a different preamp
3. Insert a UVSJ before the preamp to block any VHF interference
4. Consider the possibility of cell phone interference

I realize that you can't do much about the trees and the mounting locaton.


Maybe ADTech can suggest something I overlooked.

[bimr8]

I had the antenna installer back out. He raised the antenna by about 5.5' (see photos). Voila! Excellent reception, including WSBK and WLVI. Only very isolated pixilation has been observed since then. (Note: he originally raised it by 5', but it was found that 5.5' reduced pixilation even more)

OK great! But I now fear another problem. The antenna is unsupported by guy wires and I saw it swaying in the wind a few inches when the winds were about 16 MPH. I fear that the pole will snap or, even worse, become a projectile during a major windstorm.

I believe that the installer said that he has a 1.5" pole inserted about 4.5' into the originally-installed 2" pole. The supports attached to the condo are very solid wood so I'm not concerned about the supports popping out. The installer said that 4 points would be needed for guy wires (and didn't put in any), we probably really only have two points (?) available, both on the roof. The adjacent trees certainly can't be used as they sway even more than the antenna.

I'm afraid that I'll have to get guy wires installed. The expenses are beginning to add up to where I probably should've stayed with Comcast

Is it agreed that I'd better either get guy wires installed, OR lower the antenna and put up with worse reception? Thanks, this forum has been helpful to me, especially from rabbit73!

[MikeBear]

Originally Posted by bimr8

I'm afraid that I'll have to get guy wires installed. The expenses are beginning to add up to where I probably should've stayed with Comcast

Is it agreed that I'd better either get guy wires installed, OR lower the antenna and put up with worse reception? Thanks, this forum has been helpful to me, especially from rabbit73!

Get guy wires, it's not that expensive. Also, there's a BIG difference in a one-time charge for doing this, or paying the cable robber-barons FOREVER.

It's money well spent, if you are otherwise happy with the OTA install in general.

Be happy, just get it done. Life's too short for regrets over tv programming you can enjoy, and a little extra money up front beyond what you were hoping for.

[rabbit73]

Thanks for the new photos; they tell us a lot.

I'm not a PE who could make wind load calculations, but I'll give you my thoughts.

(Note: he originally raised it by 5', but it was found that 5.5' reduced pixilation even more)

That seems to be further proof of signal layering.

The antenna is unsupported by guy wires and I saw it swaying in the wind a few inches when the winds were about 16 MPH. I fear that the pole will snap or, even worse, become a projectile during a major windstorm.

I understand your concern. How is your liability insurance?

I believe that the installer said that he has a 1.5" pole inserted about 4.5' into the originally-installed 2" pole.

That sounds conservative.

The installer said that 4 points would be needed for guy wires

That would be ideal, but it doesn't look possible.

we probably really only have two points (?) available, both on the roof.

Two points would be enough if you use braces instead of cables.
Antenna Mast Stabilization - Guy Wires V's Rods
http://forum.tvfool.com/showthread.php?t=15836

I'm afraid that I'll have to get guy wires installed. The expenses are beginning to add up to where I probably should've stayed with Comcast

That wouldn't have been as much fun and wouldn't have gotten your creative juices flowing to meet the challenge. I sometimes have buyer's remorse from the money I have spent on antenna experiments and measuring equipment, but my life has been richer for it. If you had not tried, you would have always wondered. I consider it money well spent.

Some things you might consider:
1. Mount two braces from the roof to the mast. Add pitch pads because of roof penetration; a job for a roofer
2. Use a tripod mount on the roof. Add pitch pads because of roof penetration; a job for a roofer
3. Replace the mast with one more rigid
4. Move the upper bracket a little higher and add a third bracket between the two to reduce the sway
5. Replace the 8-bay antenna with a 91XG which has, I think, less wind load
6. Hire a PE