OTA recommendations

[rabbit73]

By PM:

Originally Posted by verder

I've seen your posts on here that are extremely informative. That lead me to register here, looking for advice as a recent cord-cutter. Problem is, my account hasn't been approved yet so I don't have permission to post. Would you be ok if I sent you a PM with my details and you could re-post that for me on the "Help with Reception" subforum?

Thanks.

Hello, verder.

Many others have to wait because the TVFool staff is very small. Some never are able to post. This forum is becoming less active; it isn't as secure since they didn't renew their certificate. There is no longer https:// in the address.

If you get tired of waiting, you can join the AVS Forum:
https://www.avsforum.com/forums/hdtv-technical.25/

I will try to help you with your OTA problem under these difficult circumstances.

I will need certain information, like a signal report, a description of your present equipment, and what channels you hope to receive.

If you are willing to give me your address and coordinates of your antenna, I can get a signal report from rabbitears.info and look at your location in a satellite view.
https://www.rabbitears.info/searchmap.php

The signal reports from TVFool now contain errors because they are using an old database to generate reports.
https://www.tvfool.com/index.php?opt...pper&Itemid=29

If this conversation continues, you should know that you are presently limited to 5 PM messages. If you don't delete the earlier PMs, I will get the message that your inbox is full.

rabbit

[rabbit73]

His reply by PM:

Originally Posted by verder

Thanks for all of the info. I'll take your advice and head over to the AVS forum. I'll post my info over there and see what I find out.

Thanks again!

[rabbit73]

Next reply by verder by PM:

Originally Posted by verder

Looking at that AVSForum site, I'm not sure where to post. I live in the Fargo area which has a 115 page thread already started, but just skimming through it, it looks like it's more about the market than specific antenna help. In fact, you were the last person to post in that thread two months ago!

So, here's my info if you are still interested in helping out. I already have a Clearstream 4Max installed on the east edge of my second floor roof (on the north side, about 2-3' up from the gutter). I have < 100' of copper-clad dual shield RG6 running west under my eave and into my house. The mast and cable is grounded. The path for the signal is: antenna -> cable -> grounding block -> cable -> internal cable jack plate -> cable -> Tablo. In other words, no splitting and only a couple of interconnects.

Before I permanently attached the antenna to my house, I made a temporary stand and tried several locations along the west and east sides of my house & garage. Part of my problem is that I have trees that are to the northwest and southeast, right in line with reported towers, and I was hoping to figure out where my "sweet spot" antenna location was. I ran the RG6 to a cheap MediaSonic digital tuner I picked up from Amazon that was connected to a TV via HDMI. I used that to get a rough signal quality reading and also would watch one channel on each carrier frequency for a minute or two to look for drop-outs or pixelation. The best place seemed to be on the east side of the house.

The funny thing about antenna placement is that I had the antenna temporarily at a point about halfway up to the peak of the house and got everything but KRDK. I didn't have any place for a ladder for permanently attaching things, so I moved my temporary stand down the slope of the house by a foot or two to the north and that got everything. Weird. RF reception almost seems to have a certain degree of black magic involved with it! :P

Note that I didn't go to the peak of my house mainly because I have the top of my fireplace chimney jutting out there -- it's a metal cylinder roughly 2' in diameter and I was thinking signal reflection / shielding may be an issue if I got too close. Additionally, trying to attach to the fascia there would have been challenging as I don't have a long enough ladder to reach that position.

Channels checked:

4-1 (KRDK)
6-1 (WDAY)
11-1 (KVLY)
13-1 (KFME)
15-1 (KVRR)
28-1 (K28MA)
30-1 (KXJB)

I now have the antenna connected to a Tablo Quad (4-tuner) DVR. The problem I'm having right now is that I occasionally get dropped recordings for channels 4, 11, 15, and 28. It doesn't happen all the time. I'm questioning if it is the Tablo or the antenna. I've heard that the Clearstream 4Max has a narrow signal reception angle, and I'm wondering if a cheaper RCA ANT751E from Menard's would be a better option:

https://www.menards.com/main/electri...4940301502.htm

I'm sure it doesn't help that I have towers almost 180 degrees apart. I need to receive both from the northwest and the southeast.

I don't have any fancy antenna equipment, but if it helps I do have an RTL-SDR and Airspy R2 SDR. I've been able to see the frequency spectrum that my antenna is putting out in the VHF/UHF bands. I was hoping to use that to see if I could tune things.

I looked up nearby cell tower locations on http://antennasearch.com/default.asp and there are some towers that are somewhat close to my location. I gave an LTE filter a shot, not really expecting much, and sure enough -- I still get weak signal indications so I think that was a bust.

Thanks for any help you can provide!

Thank you for the very thorough additional information.

We will study your problem and come back with some comments that might be helpful.

[rabbit73]

Here is a signal report for your location:
https://www.rabbitears.info/searchma...tudy_id=143302



For comparison, a TVFool signal report for your location would look like this:
http://www.tvfool.com/?option=com_wr...9038e93d573093



I don't think verder can see attachments yet. There are regular attachment to this post, and the images in the post are from my image host imgur.

[rabbit73]

Originally Posted by verder

Thanks for posting that info. Yes, you can show that picture in the thread.

OK, thanks

How did you get those tower line of site overlays into that picture? That's very cool!

I used the TVFool Interactive Browser:
https://www.tvfool.com/?option=com_wrapper&Itemid=90

The green signal lines are based on old channel data, but it gives the general idea.



Channels checked:

4-1 (KRDK) COZI, Real channel 24, 324.8 deg True, Signal Margin 39 dB
6-1 (WDAY) ABC, Real channel 21, 306.1 deg True, Signal Margin 68 dB
11-1 (KVLY) NBC/CBS, Real channel 36, 331.6 deg True, Signal Margin 53 dB
13-1 (KFME) PBS, Real channel 13, 307.5 deg True, Signal Margin 59 dB
15-1 (KVRR) Fox, Real channel 19, 111.7 deg True, Signal Margin 56 dB
28-1 (K28MA) CBS/CW, Real channel 28, 331.6 deg True, Signal Margin 40 dB
30-1 (KXJB) CBS/CW, Real channel 30, 101.7 deg True, Signal Margin 60 dB

I now have the antenna connected to a Tablo Quad (4-tuner) DVR. The problem I'm having right now is that I occasionally get dropped recordings for
channels
4-1
11-1
15-1
28-1

It doesn't happen all the time. I'm questioning if it is the Tablo or the antenna.

I have no experience with the Tablo. How do the problem channels do with a TV tuner?

I've heard that the Clearstream 4Max has a narrow signal reception angle, and I'm wondering if a cheaper RCA ANT751E from Menard's would be a better option:
https://www.menards.com/main/electri...4940301502.htm

That version of the 751 has fewer elements than the original 751.

I'm sure it doesn't help that I have towers almost 180 degrees apart. I need to receive both from the northwest and the southeast.

The CS MAX4 does have a narrow beamwidth, but since it doesn't have a reflector, it is bi-directional.

[rabbit73]

I don't have any fancy antenna equipment, but if it helps I do have an RTL-SDR and Airspy R2 SDR. I've been able to see the frequency spectrum that my antenna is putting out in the VHF/UHF bands. I was hoping to use that to see if I could tune things.

A spectrum analyzer can be very useful. It will allow you to check the SNR.



The RTL-SDR.COM V3 dongle doesn't show a whole channel with the SDR# (SDRsharp) software, but it will show part of a channel, the pilot, and the adjacent noise floor, which is sufficient to estimate the SNR.



To show more than one channel, there is free open-source software for the dongle, but it isn't ready to use; you have to assemble it in a folder from GitHub.



I like the Airspy R2 with the Spectrum Spy software.





The dB scale is only relative, not absolute.

[rabbit73]

Originally Posted by verder

You asked in the thread about Tablo vs the TV tuner. I've only really used the TV tuner to do the original setup (finding the sweet spot.) From that point it's been pretty much using the Tablo exclusively. I have not used the MediaSonic TV tuner for an extended period of time.

That said, I'll do some experimentation and some longer viewing with it on the channels I've had issues with to see if there's anything unique with that (drop-outs or what-have-you.) Thankfully the Tablo has been recording what station, day, and times the problems are occurring. I'm starting to record that info in a spreadsheet to see if I can see a pattern or anything emerge.

It's not much, but one experiment I performed has been to find the pilot frequency for each channel using my Airspy R2 + SDR#. The Airspy has a wide enough bandwidth so I can see the "whole" signal at once. I used this to see what gain setpoints I needed to place that pilot frequency peak at -40dB to -45dB. The Airspy gain setpoints ranged from 3 to 13:

KFME: 6
KVRR: 7
WDAY: 3
KRDK: 8
K28MA: 13
KXJB: 8
KVLY: 10

I realize this doesn't show any sort of bit error info or whether I've got multipath issues going on, but I'm at least able to "see" things.

Thanks for help so far and relaying my posts to the thread!!!

Yes, you can see the whole channel with the Airspy R2 and SDR#.



For signal quality, SNR and errors, I use my SONY TV and a SiliconDust HDHR.

Bad signal



Good signal





Signal Quality is similar to SNR.

Symbol Quality is the inverse of uncorrected errors; it should be 100%.

Looking at the shape of a signal can help find the best location for the antenna.









The above three images were made with an SDRplay RSP1A and SDRuno software.

[eclipsme]

Originally Posted by rabbit73

To show more than one channel, there is free open-source software for the dongle, but it isn't ready to use; you have to assemble it in a folder from GitHub.

What software is this? Thanks!

[rabbit73]

Originally Posted by eclipsme

What software is this? Thanks!

It was difficult for me to assemble the software; I'm not an expert with software. I was about ready to give up, but on the third try I got it to work.

Pete Higgins had a tutorial on the HDF forum, but that forum folded. There is part of it on the web archive. Post #12 has the best INFO on the RTL-SDR Scanner:
https://web.archive.org/web/20170627...r-10-00-a.html

I tried 3 different software versions that are listed in this post. I like the 64 Bit v1.3.0 RTLSDR Scanner best
https://www.digitalhome.ca/threads/c...5#post-3090963

RTLSDR Scanner
https://eartoearoak.com/software/rtlsdr-scanner

Releases
https://github.com/EarToEarOak/RTLSDR-Scanner/releases

go to v1.3.0 and click on assets if you have a 64-bit computer
click on rtlsdr_scan-windows-64bit.exe 41.1 MB

[eclipsme]

Originally Posted by rabbit73

It was difficult for me to assemble the software. I was about ready to give up, but on the third try I got it to work.

Pete Higgins had a tutorial on the HDF forum, but that forum folded. There is part of it on the web archive. Post #12 has the best INFO on the RTL-SDR Scanner:
https://web.archive.org/web/20170627...r-10-00-a.html

I tried 3 different software versions that are listed in this post. I like the 64 Bit v1.3.0 RTLSDR Scanner best
https://www.digitalhome.ca/threads/c...5#post-3090963

I see what you mean. Lots of pieces to be obtained from lots of places.
Thanks!
Was it worth it? Nice cheap alternative for someone that barely understands what this is!

[rabbit73]

Originally Posted by eclipsme

I see what you mean. Lots of pieces to be obtained from lots of places.
Thanks!
Was it worth it? Nice cheap alternative for someone that barely understands what this is!

It was worth it to me; it gave me a spectrum analyzer for $25. I was then able to see if the channel was there when my tuner didn't pick it up during a channel scan.

The first thing I did when learning about SDRs was download the SDR# (SDRsharp) software, which was ready to use. The dongle and SDR# will only show about 2 MHz. But, I was then able to look at part of a channel, its pilot carrier, and estimate the SNR of the channel.



I was also able to look at and listen to FM signals.



This gave me the confidence to try the spectrum analyzer for the RTL-SDR.COM V3 dongle.
https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/

I knew that if I couldn't figure out the RTLSDR Scanner, I would at least have the dongle and SDR# software.

I suggest you try the RTL-SDR.COM V3 dongle with the SDR# software to give you confidence.
Quick Start Guide
https://www.rtl-sdr.com/rtl-sdr-quick-start-guide/
Installing RTL-SDR & SDR Sharp on Win10 Made Easy - TheSmokinApe
https://www.youtube.com/watch?v=rUwRt5qn-6U

Once you have it working, then you need to learn how to adjust the gain to make a good estimate of the SNR of the channel. There is an optimum setting of the gain to show max signal with max SNR. Strong signals require less gain; weak signals require more gain.



This is my amateur video; one of these should work:

https://www.dropbox.com/s/ge923irqji...50-56.mp4?dl=0

https://www.dropbox.com/s/ge923irqji...50-56.mp4?dl=1

If you want to show the whole channel with ready-to-use software, then upgrade to the SDRplay RSP1A SDR ($100) with SDRuno software.

[eclipsme]

Originally Posted by rabbit73

It was worth it to me; it gave me a spectrum analyzer for $25. I was then able to see if the channel was there when my tuner didn't pick it up during a channel scan.

The first thing I did when learning about SDRs was download the SDR# (SDRsharp) software, which was ready to use. The dongle and SDR# will only show about 2 MHz. But, I was then able to look at part of a channel, its pilot carrier, and estimate the SNR of the channel.



I was also able to look at and listen to FM signals.



This gave me the confidence to try the spectrum analyzer for the RTL-SDR.COM V3 dongle.
https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/

I knew that if I couldn't figure out the RTLSDR Scanner, I would at least have the dongle and SDR# software.

This is not looking too difficult. SDRSharp is downloaded as a zip file and rtlsdr scanner has an installation file. The scanner is what allows you to see the entire channel (or multiples), right?

I almost stumbled by buying a clone but now I understand what to buy.

In another post, you advised me to point my antenna towards Orlando rather than Palm Beach. I have done so to good effect. CBS in Orland came in 80-100% right away, but then to 0 and back again. I want to use the scanner to lock in that station.

Sorry to appropriate the thread from the OP.

[rabbit73]

Originally Posted by eclipsme

This is not looking too difficult. SDRSharp is downloaded as a zip file and rtlsdr scanner has an installation file. The scanner is what allows you to see the entire channel (or multiples), right?

Uh, no; not exactly. I edited my post #11 above and added an image and a video. Please look at it.

I have used 3 SDRs:



For $25 you can buy an RTL-SDR.COM V3 dongle and download SDR# software. With it you will only be able to see part of a TV channel. The dongle will only show about 2 MHz, not a whole TV channel which is 6 MHz wide.

If you use the free open-source DIY spectrum analyzer software (RTLSDR Scanner) for the dongle, you can see more than one channel. You have to assemble the software yourself in a folder to use it. The way it is able to show more than one channel is by stitching together sections to make the entire scan.

If you want to see the whole channel with ready-to-use software, you have to buy an SDRplay RSP1A SDR ($100) and download the SDRuno software.

If you want a spectrum analyzer with ready-to-use software you have to buy an Airspy R2 SDR ($200) and download the SDR# software which will include the Spectrum Spy Spectrum Analyzer software.

Sorry to appropriate the thread from the OP.

The OP and I are both interested in SDRs and feel that they are a useful tool for solving reception problems. I don't think we went too far off topic.

[rabbit73]

Back on topic
From PM:

Originally Posted by verder

I'll use Spectrum Spy across the UHF band and take a screen capture of what I see. I've only looked at individual channels using SDR#, and that was after tweaking the gain for each.

This makes me wonder how the Tablo tuner operates. "How do it know" that it needs to crank the gain for some channels but also not crank it as high for channels that are coming in loud and clear? It's got 4 separate tuners, so it presumably should be able to dynamically adjust the gain based on whatever channel each tuner is being tuned to. Obviously, gain doesn't mean much if there's a lot of noise or interference that is distorting the original signal.

As always, thanks for your insight!

I assume that there is an internal amp to compensate before splitting to four tuners like in the TiVo. Each tuner should have its own AGC in use for the particular channel used by that tuner.

Ideally, the AGC shouldn't alter the SNR of the signal unless it is extremely strong or extremely weak; IOW, within its operating range.

Your additional tests should give you more clues.

Since your two directions are almost 180 degrees apart, you will need a bi-directional antenna or 2 separate antennas. The ANT 751 is not bi-directional, but your AD 4MAX is bi-directional since it doesn't have a reflector. I have some concern about the 4MAX because of its narrow beamwidth. If its aim is optimum for one direction, it might be off for the other direction.

A DB4e without a reflector would have a wider beamwidth, but perhaps not quite as much gain.

It looks like your present antenna location can "see" in both directions, but the antenna might not be high enough for the signals to clear the trees. Trees can seriously affect the incoming signals, especially when they are wet. Also, when the wind moves the branches it creates multipath problems.
http://www.hdtvprimer.com/ANTENNAS/siting.html
scroll down to Trees and UHF

You mentioned earlier that when you moved the antenna higher, you lost a channel. This seems counterintuitive, but is caused by layering:



I'm presently living in a retirement facility on lockdown. My previous room was on the first floor and an indoor antenna did quite well. When I was moved to the 2nd floor, I thought the additional height would help, but there is a tree in the signal paths.



and when the wind blows, it really messes with the signal:
https://www.dropbox.com/s/8gsw9t1zsr...Path2.mp4?dl=0

https://www.dropbox.com/s/8gsw9t1zsr...Path2.mp4?dl=1

this is what the signal looks like with a strong wind:
https://www.dropbox.com/s/ig3va499k2...Path4.mp4?dl=0

https://www.dropbox.com/s/ig3va499k2...Path4.mp4?dl=1

[eclipsme]

Originally Posted by rabbit73

Uh, no; not exactly. I edited my post #11 above and added an image and a video. Please look at it.

I have used 3 SDRs:



For $25 you can buy an RTL-SDR.COM V3 dongle and download SDR# software. With it you will only be able to see part of a TV channel. The dongle will only show about 2 MHz, not a whole TV channel which is 6 MHz wide.

If you use the free open-source DIY spectrum analyzer software (RTLSDR Scanner) for the dongle, you can see more than one channel. You have to assemble the software yourself in a folder to use it. The way it is able to show more than one channel is by stitching together sections to make the entire scan.

If you want to see the whole channel with ready-to-use software, you have to buy an SDRplay RSP1A SDR ($100) and download the SDRuno software.

If you want a spectrum analyzer with ready-to-use software you have to buy an Airspy R2 SDR ($200) and download the SDR# software which will include the Spectrum Spy Spectrum Analyzer software.
The OP and I are both interested in SDRs and feel that they are a useful tool for solving reception problems. I don't think we went too far off topic.

RTLSDR Scanner is available as executable install. Hopefully making this part much easier:
https://github.com/EarToEarOak/RTLSDR-Scanner/releases

Your video quite nicely shows the affect of the gain control. I look forward to playing with this.

I have the dongle on order, along with an adapter. Should be here tomorrow...

[rabbit73]

Originally Posted by eclipsme

RTLSDR Scanner is available as executable install. Hopefully making this part much easier:
https://github.com/EarToEarOak/RTLSDR-Scanner/releases

Your video quite nicely shows the affect of the gain control. I look forward to playing with this.

I have the dongle on order, along with an adapter. Should be here tomorrow...

I'm glad the video helped you; it is an important concept when using the dongle with SDR#.

Adjusting the gain of the RTLSDR Scanner is a little different. You raise the gain until the noise floor starts to rise and then stop. More precisely, when it starts to rise you back it off a little.

Gain set too low:



Correct gain setting:



Gain set too high:



With the RSP1A and Airspy R2 you adjust the gain and other contols for max SNR.

Good luck with your adventure.

[rabbit73]

Originally Posted by verder

Part of my problem is that I have trees that are to the northwest and southeast, right in line with reported towers, and I was hoping to figure out where my "sweet spot" antenna location was.

I looked at some satellite and ground views of your location. I think the trees are a significant part of your reception problem; they appear to be taller than your antenna.

I will not post any images without your permission.

[rabbit73]

Originally Posted by verder

Yes, I agree trees are the biggest problem. I'd have to get a quite a tall pole to be able to reach an unobstructed view. I don't think that's going to happen so I may just have to live with the occasional drop in signal.

Thanks.

I think you have done a good job finding the best antenna location available on your property without going to extreme measures like a push-up mast with guy wires in the back yard.

Your signal report indicates that a preamp isn't necessary, but the actual signals arriving at your antenna might be weaker because of the trees.

The only other possibility I can think of is an antenna with a wider beamwidth.

If you used two antennas, one for each direction, there would be the problem of combining them or having to switch them.



Channels checked:

4-1 (KRDK) COZI, Real channel 24, 324.8 deg True, Signal Margin 39 dB
6-1 (WDAY) ABC, Real channel 21, 306.1 deg True, Signal Margin 68 dB
11-1 (KVLY) NBC/CBS, Real channel 36, 331.6 deg True, Signal Margin 53 dB
13-1 (KFME) PBS, Real channel 13, 307.5 deg True, Signal Margin 59 dB
15-1 (KVRR) Fox, Real channel 19, 111.7 deg True, Signal Margin 56 dB
28-1 (K28MA) CBS/CW, Real channel 28, 331.6 deg True, Signal Margin 40 dB
30-1 (KXJB) CBS/CW, Real channel 30, 101.7 deg True, Signal Margin 60 dB

I now have the antenna connected to a Tablo Quad (4-tuner) DVR. The problem I'm having right now is that I occasionally get dropped recordings for
channels
4-1
11-1
15-1
28-1

It doesn't happen all the time. I'm questioning if it is the Tablo or the antenna.

[rabbit73]

Originally Posted by verder

Here's the SpectrumSpy trace from my antenna:

https://imgur.com/a/XMGGyx7

Thank you for the UHF scan; nicely done.

KVRR virtual 15-1 RF 19 shows a little more than the minimum SNR for reception, but could be a problem at times

WDAY virtual 6-1 RF 21 is your strongest channel; shouldn't be a problem

KRDK virtual 4-1 RF 24 is a little stronger than KVRR; could be a problem at times

K28MA virtual 28-1 RF 28 is very weak; doesn't look strong enough for tuner lock in this scan

KXJB virtual 30-1 RF 30 is fairly strong but shows possible multipath problem. It is listed as second in strength after WDAY, but is a low power station
https://www.rabbitears.info/tvq.php?...s&facid=185885

KVLY virtual 11-1 RF 36 shows just barely enough SNR for a tuner lock and would be expected to have problems

This is my UHF; CH 14 doesn't decode. I like to show the settings and have added arbitrary numbers to the gain scale. I bring the gain up until the noise floor just starts to rise and stop, which should show the correct SNR.



The weak signals got a little better this evening:
Videos, no audio

https://www.dropbox.com/s/eusj9k25wg...08-07.mp4?dl=0

https://www.dropbox.com/s/eusj9k25wg...08-07.mp4?dl=1

Here is FM and VHF-High, no audio
CH 7 is around 175 MHz; it is damaged by multipath and doesn't decode
CH 11 is around 200 MHz and usually does OK; the noise level is high

https://www.dropbox.com/s/fnjyuttou2...54-35.mp4?dl=0

https://www.dropbox.com/s/fnjyuttou2...54-35.mp4?dl=1

[rabbit73]

Originally Posted by verder

You mentioned: "The only other possibility I can think of is an antenna with a wider beamwidth." Is there anything available that is at least 180deg bidirectional that has a wider beam width? Is the ClearStream 4Max as good as I'm going to get, or are there alternatives?

I had thought that a Antennas Direct DB4e with the reflector removed might be worth a test. You would have to add a dipole for VHF channel 13.

I will try to find some antenna patterns; they are getting hard to find.