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Old 11-Apr-2017, 9:22 PM   #1
kenh999
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Pesky Weird (?) Reception Issue

We recently dropped TWC-Spectrum CATV and went OTA and Stream for TV. Prior to this we had a Winegard Flatwave on our primary TV in the living room for backup when CATV went out. Reception was fairly good so I figured that an exterior antenna would be good. Well, it is, kinda.

We're in Summerville, SC - Charleston area. Two primary towers are ~30 miles away and carry our channels of interest. Am only interested in the transmitters at 97 and 99 degrees. Anything else is gravy. The antenna is aimed correctly. Here's the plot.

http://www.tvfool.com/?option=com_wr...e6a45958be8c1c

My problem is usually with Ch. 36 (ABC). Sometimes it's weak, most time absolutely ZERO dB. BUT, Ch. 50 (NBC) and 24 on same tower/heading will usually be great. Occasionally 50 will drop out but more often it's 36. I'm including a table with a few sets of signal readings.

Current setup:
Antenna: 1ByOne digital amplified, Model: OUS00-0550; Gain 5-8dB, 8-11dB; Amp Gain 18dB. 70 mile rated. Mounted on a Winegard DS-3000 Pipe Mount attached to fascia at roof peak ~25' above ground. (See pics).
Cable: New 25' RG-6 from roof to CATV demarc box. Into a ground block then to a new BAMF SB-2003 splitter.
2 outputs via existing CATV cable to 1 BR (15') and LR (~30-35ft).
Amp is at the LR TV. Reception on most channels without the amp is POOR.

Also, if I disconnect exterior antenna from the bedroom TV and connect a cheap interior flatwave antenna I can get a 2-4 bar Ch. 36 signal. That TV does not give dB readings.

Also attaching a pic that shows the antenna view on the 97-99 heading. Obviously, trees. They are about 30-35 yds. away.

If it means anything I sometimes see dB levels on channels 50 and 24 fluctuate 2-4 dB within a few mins.

Appreciate any advice!

Ken







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Old 11-Apr-2017, 10:31 PM   #2
JoeAZ
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Hi Ken,

The trees are a definite problem which you cannot change. Another issue
would be splitting an already weak signal. I install antennas several times
per week. I have not had good luck/outcomes with your type of antenna.
I would try the following..... I would connect a flatpanel tv to your antenna
while on the roof using a 5-10 foot RG6 cable. See what you get. If things
improve dramatically, you have issues with the cable/runs/amp/splitter.
If things don't change dramatically, you have a weak signal at the antenna.
The MCM 4 or 8 bay antennas work well for UHF and are relatively inexpensive.
The MCM high band antennas work on Rf 7-13 and are quite cheap, actually.
Another option would be the Winegard 7694p, mounted about 10ft higher than
current. The Winegard is UHF and Hi-VHF. With the MCM antennas, I ALWAYS
recommend two different cable, one for each antenna and an A/B switch.
Let us know what you find.........
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Old 12-Apr-2017, 1:36 PM   #3
ADTech
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Quote:
With the MCM antennas, I ALWAYS
recommend two different cable, one for each antenna and an A/B switch.
Joe,

If you're combining a UHF antenna with a VHF antenna, use a UVSJ. It greatly simplifies the installation and the subsequent customer experience. There's no need for a two-cable run and an A-B switch in this configuration. There is no benefit to the more complex configuration.

Ken,

Location, location, location.

If the antenna is installed in what amounts to a dead spot for one or more channels, it won't work. It's very common, especially when behind trees or other obstructions like buildings, for such dead spots to occur. The recommended course of action is to try multiple locations using only temporary mounts. Find a spot where it works before you break out the drill, don't use the drill until that sweet spot is located.

Trees directly in the signal path cause me to simply throw all predictions out the window. Once cannot expect or estimate the extent (or lack thereof) of their impact on the incoming signals.

The selection of a small LPDA antenna such as yours should be completely appropriate given your TVFool plot. However, I can't figure out from the obtuse descriptions whether you simply have an indoor amplifier or if it's split power supply/inserter and remote amplifier configuration. If it's a simple indoor amplifier, placing at a single TV set is probably too late as there's very little it can do to improve reception. Based on your plot, an amplifier would be ill-advised anyway due to the calculated strong signals. However, remember my comment about the trees...

You didn't identify the make and model of your TV set that you used to compile the chart, but I can assume that the readings in the rightmost columns are of the SNR values posted by the tuner and are not actual power levels. be aware these readings are not an accurate indication of received signal power, they're an indication of how much above the signal floor the signal is. Generally, a SNR of around 15 dB (+/-1) is required for decoding. Increases in the SNR improve your margin to dropout (reception failure). SNR readings will top out in the mid 30s regardless of what you do. Due to the effects of AGC and other digital magic, the change in the SNR will NOT be perfectly linear across the range of the displayed values. FWIW, if you can get the SNR into the low 20s, you usually have sufficient fade margin for the majority of situations. However, when those trees are wet and the wind is blowing, you can almost expect reception failure, so do keep your expectations in check. Think of the nursery rhyme about Humpty Dumpty...

If you want to try a preamp that you can pick up locally, Home Depot stores carries the Winegard LNA200. While I'm not a fan of it, I note it as a utility device that just happens to be available almost anywhere. Assuming your existing amp is simply an indoor amp (put it off to the side), the LNA200 can be installed at the antenna, and the power supply inserter at either TV set (your splitter is diode-steered and will pass power though it to the amp). If it isn't an indoor amp that you have, then never mind.

Good luck!
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Last edited by ADTech; 12-Apr-2017 at 1:41 PM.
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Old 12-Apr-2017, 3:55 PM   #4
kenh999
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Quote:
Originally Posted by ADTech View Post
Joe,

If you're combining a UHF antenna with a VHF antenna, use a UVSJ. It greatly simplifies the installation and the subsequent customer experience. There's no need for a two-cable run and an A-B switch in this configuration. There is no benefit to the more complex configuration.

Ken,

Location, location, location.

If the antenna is installed in what amounts to a dead spot for one or more channels, it won't work. It's very common, especially when behind trees or other obstructions like buildings, for such dead spots to occur. The recommended course of action is to try multiple locations using only temporary mounts. Find a spot where it works before you break out the drill, don't use the drill until that sweet spot is located.

Trees directly in the signal path cause me to simply throw all predictions out the window. Once cannot expect or estimate the extent (or lack thereof) of their impact on the incoming signals.

The selection of a small LPDA antenna such as yours should be completely appropriate given your TVFool plot. However, I can't figure out from the obtuse descriptions whether you simply have an indoor amplifier or if it's split power supply/inserter and remote amplifier configuration. If it's a simple indoor amplifier, placing at a single TV set is probably too late as there's very little it can do to improve reception. Based on your plot, an amplifier would be ill-advised anyway due to the calculated strong signals. However, remember my comment about the trees...
According to 1ByOne's response to a question on it's Amazon listing "the antenna has built-in amplifier, and the white box on the picture is power supply box." I have the power supply at the LR TV. Product webpage here: https://www.1byone.com/TV-Accessorie...nna/OUS00-0550
You didn't identify the make and model of your TV set that you used to compile the chart, but I can assume that the readings in the rightmost columns are of the SNR values posted by the tuner and are not actual power levels.
Yes, they are SNR values. TV is a 2012 Samsung LN 40D630M3F.
be aware these readings are not an accurate indication of received signal power, they're an indication of how much above the signal floor the signal is. Generally, a SNR of around 15 dB (+/-1) is required for decoding. Increases in the SNR improve your margin to dropout (reception failure). SNR readings will top out in the mid 30s regardless of what you do. Due to the effects of AGC and other digital magic, the change in the SNR will NOT be perfectly linear across the range of the displayed values. FWIW, if you can get the SNR into the low 20s, you usually have sufficient fade margin for the majority of situations. However, when those trees are wet and the wind is blowing, you can almost expect reception failure, so do keep your expectations in check. Think of the nursery rhyme about Humpty Dumpty...

If you want to try a preamp that you can pick up locally, Home Depot stores carries the Winegard LNA200. While I'm not a fan of it, I note it as a utility device that just happens to be available almost anywhere. Assuming your existing amp is simply an indoor amp (put it off to the side), the LNA200 can be installed at the antenna, and the power supply inserter at either TV set (your splitter is diode-steered and will pass power though it to the amp). If it isn't an indoor amp that you have, then never mind.

Good luck!
Because it requires running new cable through the attic and down a wall I had not considered mounting on the opposite end of the house. Took a look this morning and the 97-99 degree path from that end of the house looks much better.



I'll get a 50' RG-6 and do a test by running the cable in thru the door to the LR TV. I can temporarily attach the antenna to a footstool sitting on the roof peak. I don't relish the idea of the attic and wall work but...

Will report back after I test the new location.

Thanks!
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Old 12-Apr-2017, 7:19 PM   #5
JoeAZ
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"If you're combining a UHF antenna with a VHF antenna, use a UVSJ. It greatly simplifies the installation and the subsequent customer experience. There's no need for a two-cable run and an A-B switch in this configuration. There is no benefit to the more complex configuration."

I respectfully disagree.
The purpose of running two different cables is to keep the signals
separate and distinct. A "UVSJ" or combiner as it were, is nothing more than
a splitter used in reverse. When you use a combiner, both signals suffer. Period. Perhaps in the laboratory it works out differently but installing antennas 5 days a week tells a different story. Any combo antenna, regardless of brand, compromises. Period. I have NEVER found a UHF/VHF antenna that works as well as a separate antenna for UHF and another for VHF. Yes, the A/B switch is inconvenient but if a customer wants the best possible signal there's no better option.....
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Old 12-Apr-2017, 7:19 PM   #6
ADTech
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That sounds like an excellent plan, let us know how it works out.

I did see that comment in the Amazon review section and I can pretty much guarantee it's bass-ackwards based on what I do see unless they stuffed an amplifier on the front of the antenna inside that nosecap. If that cap can be popped off without damage, a photo there would be instructive. If you have a chance, can you provide photos of the area of the antenna where the coax attaches and one or more photos of the indoor module? Just curious as their seems to be no documentation on the seller's website.
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Last edited by ADTech; 12-Apr-2017 at 7:46 PM.
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Old 12-Apr-2017, 7:31 PM   #7
ADTech
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Quote:
A "UVSJ" or combiner as it were, is nothing more than
a splitter used in reverse
Your understanding is incomplete.

A UVSJ is NOT a simple broadband splitter such as is usually used for connecting multiple sets, it is a FREQUENCY-SELECTIVE splitter/joiner (it's a reciprocal device, it may be used for either function). The VHF port only admits VHF frequencies and rejects UHF frequencies while the UHF port does exactly the opposite. The two cleaned-up frequency bands are then combined with minimal loss, usually under a dB or so, worst case.

In the attached image which is a measurement of one of our U/V combiners I did a while back, the yellow trace is the through insertion loss measurement of the VHF input to the output, the magenta (pink) trace is of the UHF input to the output. As can be seen the opposite set of frequencies is attenuated by > 30 dB for both ports.



The UVSJ device has been used successfully for decades for the express purpose of combining separate UHF and VHF antennas. No need to go backwards in time and end up with an inconvenient outcome for your customers. There's a way better way than how you've been doing it.
Attached Images
File Type: jpg A_D_EU385CS-1F_Freq_Response.jpg (141.8 KB, 545 views)
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Last edited by ADTech; 12-Apr-2017 at 7:46 PM.
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Old 12-Apr-2017, 8:53 PM   #8
kenh999
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Quote:
Originally Posted by ADTech View Post
That sounds like an excellent plan, let us know how it works out.

I did see that comment in the Amazon review section and I can pretty much guarantee it's bass-ackwards based on what I do see unless they stuffed an amplifier on the front of the antenna inside that nosecap. If that cap can be popped off without damage, a photo there would be instructive. If you have a chance, can you provide photos of the area of the antenna where the coax attaches and one or more photos of the indoor module? Just curious as their seems to be no documentation on the seller's website.
VERY Disappointing results. Before I get into that, you are correct about the amp.

Pulled nosecap off and here's what is there






Other end w/coax connection




Signal reception is much worse. Totally surprised me. Using a new 50' RG-6 and only get TWO channels, 24 and 7. Tried adding some elevation above trees in distance to no avail. Here's 2 pics to give an idea of what I did.

second try w/more up angle


first try



I'm close to being pissed. I get better reception with the indoor Winegard non-amp flatwave. Geez. Even the original location through trees is better.

Damn



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Old 12-Apr-2017, 11:22 PM   #9
JoeAZ
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Ken,
Did you try as I suggested and connect your antenna on the roof to
a small flatpanel tv, also on the roof using 5-10 feet of RG6 ?
Moving the antenna, up, down and around the roof may help
provide insight as you check your various channels.....

Regards,
Joe
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Old 12-Apr-2017, 11:38 PM   #10
kenh999
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Joe,

I don't have a TV small enough to safely do that.

I moved the antenna back to its exact previous (original) location and guess what? I got the SAME poor reception (only 2 channels) I described above when I had it at the opposite end of the roof. How could that be? I know it's silly, but it seems like the antenna got stuck on the poorer signal. Even tried power cycling the amp's power supply to no avail.

Both TVs are now using indoor flatwave antennas with better reception. Only channel 36 is iffy.

*Sigh*
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Old 13-Apr-2017, 12:34 AM   #11
JoeAZ
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Just a thought.... Have your tried temporarily connecting your flatwave
indoor antenna to the mast outside??? If it works better, then you have
an antenna issue.....
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Old 13-Apr-2017, 7:26 PM   #12
kenh999
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I took the Winegard Flatwave to the roof and taped it to the same stepstool used yesterday for the 1ByOne antenna. Connected it via splitter (had no barrel connector) to the same coax as yesterday. I tested it with and without the amp in both locations.



Two conclusions and a new issue:

1. The flatwave performed better than the 1byone antenna.

2. The new location with a more open path on 97-99 degree heading is preferable.

3. No idea why I lost Ch. 7.

For comparision purposes below is a table with the SNR values for today's test added, with the understanding that SNR values are not the same as signal values alone.



So, your recommendations??

Different/higher gain antenna?

Better Preamp?

Last edited by kenh999; 13-Apr-2017 at 7:51 PM.
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Old 13-Apr-2017, 9:14 PM   #13
ADTech
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Quote:
The flatwave performed better than the 1byone antenna.
Then I would suspect there is a defect in the antenna.

Quote:
No idea why I lost Ch. 7.
The Flatwave isn't much on VHF in the first place, then you made an unknowing mistake by attaching it to the metal chair frame. The VHF portion of a Flatwave is around its perimeter and the metal chair frame probably has severely detuned it. See if you can tape the Flatwave to a cardboard box or similar and try again.

FWIW, anyone curious about the Flatwave and Winegard's "Air" and the original "Rayzar" (superceded), they all have the same element in them with the "Air" adding a couple of wires behind it to serve as a reflector.

Quote:
So, your recommendations??
It all boils down to the right antenna in the right place. From our catalog and based on the totality of the information you've provided, I'd put a ClearStream 2V up there with no amplifier at all. I suggest it because it's readily available at almost every Walmart and Best Buy in the country. ...not to overlook mentioning, the sales help pay my salary!
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Last edited by ADTech; 13-Apr-2017 at 9:17 PM.
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Old 13-Apr-2017, 10:33 PM   #14
kenh999
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Quote:
Originally Posted by ADTech View Post
Then I would suspect there is a defect in the antenna.

The Flatwave isn't much on VHF in the first place, then you made an unknowing mistake by attaching it to the metal chair frame. The VHF portion of a Flatwave is around its perimeter and the metal chair frame probably has severely detuned it. See if you can tape the Flatwave to a cardboard box or similar and try again.
Yep, that was it. Receiving Ch. 7 fine now.
FWIW, anyone curious about the Flatwave and Winegard's "Air" and the original "Rayzar" (superceded), they all have the same element in them with the "Air" adding a couple of wires behind it to serve as a reflector.

It all boils down to the right antenna in the right place. From our catalog and based on the totality of the information you've provided, I'd put a ClearStream 2V up there with no amplifier at all. I suggest it because it's readily available at almost every Walmart and Best Buy in the country. ...not to overlook mentioning, the sales help pay my salary!
Thanks! I see that model on Amazon has many good reviews. Just ordered it.

Contrary to my usual practice I threw away the shipping boxes for the 1byOne antenna before I was sure it worked. Grrrr! Now to find a box and get it packed for return.
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Old 13-Apr-2017, 11:55 PM   #15
JoeAZ
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Hi Ken,
It is very telling that the indoor flatwave antenna outperformed
the 1byone.... I would suggest the MCM 4bay UHF antenna (30-2425)
and the MCM Hi-VHF antenna (30-2475). Priced at $26.99 and $24.99),
respectively. You could use a combiner so as to run only one RG6
and not have to run another cable. The simple dipole of clearstream
2v antennas does help on Hi-VHF but not that much.....
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Old 14-Apr-2017, 4:14 AM   #16
ADTech
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If the calculated noise margin for the station on channel 7 is accurate, the simple VHF dipole of the C2V will provide about 10,000x more signal power (at the antenna terminals, before distribution losses) than is required for tuning in the channel. The big VHF antenna from MCM would increase that by a factor of approximately 5x to 10x (depends on frequency).
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