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Old 11-Nov-2014, 2:14 AM   #61
rabbit73
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Quote:
10.1 continues to get sporadic RS Uncorrected Errors as well as 33-1 and 49-1. Nothing else seems to do that.

Oddly enough even with the attenuator, 33-1, 33-2, and 33-3 continue to be around 67% signal strength (which is what they are at after inserting the LNA 100 and before putting the 3 dB attenuator in the mix).

I don't mind losing the KRFT channels as there is nothing on there I watch anyway.

Do you have any other ideas I should try?
Thanks for the report.

While the fix helped for a while, it looks like it was not permanent. Since the errors increased when the signals were stronger, this suggests to me that you should try increasing the attenuation between the C2V and the input of the AC7.

I think you said that you had 3 of the 3 dB attenuators. So, try 6 dB (they stack in series don't they?) for a few days, and then increase it to 9 dB before giving up on this idea. This should not affect the reception with the 91XG.

Code:
    91XG > LNA 100 > 
                    \
                     AC7 > Roamio > Basement TV
                    /
  C2V > attenuator >
If you add the whole stack of attenuators to the input jack of the AC7 it might put too much strain on it. You can insert them in the middle of the coax with a short jumper coax and an F81.

Have you tried tilting the 91XG up a little to see if it improves the reception of Fox?

I'll stick around with you until I run out of longshot ideas to try, or until you give up and settle for what you have now.

Are the coax lines from the antennas grounded with grounding blocks that are connected to your electrical system ground? I'm thinking about interference with this question. It's also a good idea for electrical safety.

Do all your pieces of AC operated equipment have 2-wire power cords, or do some have 3-wire cords?

Are you using power strips that have provision for coax grounding? If so, are you using that feature? It's not always a good idea to do that.

The power strip will ground the coax shield if it is connected to a properly wired 3-wire outlet. But, the coax center conductor might pickup electrical interference from the other devices plugged into the strip, and the TV signal might be degraded if there is a surge protector connected between the center conductor of the coax and the shield.

What make and model TV is directly connected to the Roamio output? Does it have a signal strength indicator or a Diagnostics Screen? Are you using an HDMI cable, or what between them?



Virtual 33.1 KSPR-DT, real channel 19, is your strongest station, but its virtual number is not shown on your tvfool report:
http://www.tvfool.com/?option=com_wr...d24362e8886d03
Attached Images
File Type: png mulliganman's antenna setup 2 (2).png (116.7 KB, 1347 views)

Last edited by rabbit73; 11-Nov-2014 at 9:48 AM. Reason: Had the LNA100 in the wrong coax
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Old 12-Nov-2014, 11:04 PM   #62
mulliganman
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Quote:
Originally Posted by rabbit73 View Post
Thanks for the report.

While the fix helped for a while, it looks like it was not permanent. Since the errors increased when the signals were stronger, this suggests to me that you should try increasing the attenuation between the C2V and the input of the AC7.

I think you said that you had 3 of the 3 dB attenuators. So, try 6 dB (they stack in series don't they?) for a few days, and then increase it to 9 dB before giving up on this idea. This should not affect the reception with the 91XG.

Code:
    91XG > LNA 100 > 
                    \
                     AC7 > Roamio > Basement TV
                    /
  C2V > attenuator >
If you add the whole stack of attenuators to the input jack of the AC7 it might put too much strain on it. You can insert them in the middle of the coax with a short jumper coax and an F81.

Have you tried tilting the 91XG up a little to see if it improves the reception of Fox?

I'll stick around with you until I run out of longshot ideas to try, or until you give up and settle for what you have now.

Are the coax lines from the antennas grounded with grounding blocks that are connected to your electrical system ground? I'm thinking about interference with this question. It's also a good idea for electrical safety.

Do all your pieces of AC operated equipment have 2-wire power cords, or do some have 3-wire cords?

Are you using power strips that have provision for coax grounding? If so, are you using that feature? It's not always a good idea to do that.

The power strip will ground the coax shield if it is connected to a properly wired 3-wire outlet. But, the coax center conductor might pickup electrical interference from the other devices plugged into the strip, and the TV signal might be degraded if there is a surge protector connected between the center conductor of the coax and the shield.

What make and model TV is directly connected to the Roamio output? Does it have a signal strength indicator or a Diagnostics Screen? Are you using an HDMI cable, or what between them?



Virtual 33.1 KSPR-DT, real channel 19, is your strongest station, but its virtual number is not shown on your tvfool report:
http://www.tvfool.com/?option=com_wr...d24362e8886d03
I put two of the 3dB attenuators back to back connected to the C2V coax, an F81 connector, then a short piece of coax to the AC7. Oddly, it seemed to not really affect the signal strength of KSPR.

I know you asked about the virtual number of KSPR. ABC is 33-1, CW is 33.2, and Antenna TV is 33-3.

I don't know about the grounding blocks.

Your question about the AC operated equipment having 2 wire power cords or 3 wire cords I need some clarification on because I'm not sure what you are asking.

Are you using power strips that have provision for coax grounding? If so, are you using that feature? It's not always a good idea to do that. Yes I have this surge protector in use in the attic (but am unsure about any coax grounding provision): http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

Here is a link to the model of the TV I have connected to the Roamio: http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

I know the TV has a signal strength indicator. I'm not sure about a Diagnostic screen. I'm sure all of my TV's tuners are "better" than any of the DVR's I have on hand (Tivo Roamio and a Channel Master DVR+, which is not in use). It seems all TV's seem to be that way...

I'm also sending you a Pm with the same coordinates I sent ADTech so you can get a better idea of location, obstacles, etc. I am also going to send you a second set of coordinates for something that I am wondering if it could be causing me interference.

I've asked this a couple of times but haven't gotten any responses so I'll ask again. If I moved the 91XG to the peak of the 2nd story of my home, what equipment would I need for mounting it there. I'm hoping you may be able to answer after looking at the coordinates I gave you.

Last edited by mulliganman; 12-Nov-2014 at 11:11 PM.
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Old 13-Nov-2014, 12:31 AM   #63
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Quote:
Originally Posted by mulliganman View Post
...
I've asked this a couple of times but haven't gotten any responses so I'll ask again. If I moved the 91XG to the peak of the 2nd story of my home, what equipment would I need for mounting it there. I'm hoping you may be able to answer after looking at the coordinates I gave you.
Are you asking about the mechanical process of mounting an antenna on the roof peak?

If so, you'll need some sort of mast and a way to support it. This could be a gable end bracket, a tripod, a chimney mount, or a ridge bracket with guy wires. Mostly it depends on your roof configuration and which method most appeals to you.

Look here for some ideas about mounting brackets - http://www.antennapartsoutlet.com/ - I've bought from them. The shipped fast and had reasonable shipping charges.
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Old 13-Nov-2014, 3:07 AM   #64
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You can also use a satellite-style J-mount, but you're be restricted to a length of about a meter or so.
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Old 13-Nov-2014, 4:02 AM   #65
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Originally Posted by ADTech View Post
You can also use a satellite-style J-mount, but you're be restricted to a length of about a meter or so.
Good to know. I was wondering if you would be willing to check out these coordinates I sent rabbit and see if this might be causing the signal errors I continue to see.

The coordinates are 37.025154, -93.205803
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Old 13-Nov-2014, 1:39 PM   #66
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Don't know. That location doesn't appear when I do a tower search in the area. Assuming it belongs to one of the local fire protection districts, it will be operating in either the 150-155 MHz or the 450-455 MHz bands.

The only way you'd be able to positively correlate your intermittent decoding errors with some local RF transmission would be to sit there with a spectrum analyzer watching it and your diagnostic screen (or display) and see if you can spot some sort of broadcast that occurs at precisely the same time as a decoding error. It would be like looking for a needle in a haystack unless you could narrow down any of the variables.
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Old 13-Nov-2014, 8:34 PM   #67
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Originally Posted by ADTech View Post
Don't know. That location doesn't appear when I do a tower search in the area. Assuming it belongs to one of the local fire protection districts, it will be operating in either the 150-155 MHz or the 450-455 MHz bands.

The only way you'd be able to positively correlate your intermittent decoding errors with some local RF transmission would be to sit there with a spectrum analyzer watching it and your diagnostic screen (or display) and see if you can spot some sort of broadcast that occurs at precisely the same time as a decoding error. It would be like looking for a needle in a haystack unless you could narrow down any of the variables.
Well I see. I'm still looking for any kind of patterns with the errors, but I guess unless rabbit has other ideas that only leaves changing out the C2V to something more directional and see if that resolves these signal errors. Is that fair to say (since two 3dB attenuators have been added and the signal errors still occur)?

If it is, what would be some reasonable alternatives to consider? I really like the form and aesthetics factor of the C2V especially when coupled with the more directional 91XG and hate the idea of replacing it but the cutouts on 33-1, its subchannels, and 10-1 are driving me nuts. The only other channel that on a more rare occurance that has the occasional error is 49-1 Fox. Everything else always sits at 0 since switching to yours and rabbits suggestions.

The reason I have been inquiring more about how to mount the 91XG on the peak of the roof as you mentioned is because of the possibility of needing another directional to eliminate the errors on 33-1, its subchannels, and 10-1 while maintaining error free on the other channels. I thought it might be difficult to place two directional antennas where the two in use are located (not to mention being a bit of an eye sore).

Last edited by mulliganman; 13-Nov-2014 at 9:30 PM.
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Old 14-Nov-2014, 12:56 AM   #68
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Quote:
but the cutouts on 33-1, its subchannels, and 10-1 are driving me nuts.
Don't give up yet, I still have some more ideas for you to try.

You are not the only Roamio owner that has a love/hate relationship with his DVR:
Tivo Roamio Plus can be great, but check it out carefully before keeping it longer than 30 days
http://www.avsforum.com/forum/42-hdt...n-30-days.html

Thanks for the exact coordinates. I ran your FM fool report to see if there were any strong FM signals that might be causing interference. With FM fool there is no link like there is for tvfool reports. I deleted the numbers after the decimal point to protect you, even though the report only shows two digits after the decimal point. I also ran some tvfool reports at different heights, but I will not post them unless you give me permission to do it. They also have truncated coordinates, so the approx. coordinates are pretty far away from your exact location. This is your FM signal report:



When you make a reply to one of my posts, it is not necessary to quote the entire post. You can delete the parts of the quote that are not needed, or you can copy and paste what I said, highlight it and click on the quote icon at the top of the text box above the red A, which will add the quote box to your post.



Quote:
The only way you'd be able to positively correlate your intermittent decoding errors with some local RF transmission would be to sit there with a spectrum analyzer watching it and your diagnostic screen (or display) and see if you can spot some sort of broadcast that occurs at precisely the same time as a decoding error. It would be like looking for a needle in a haystack unless you could narrow down any of the variables.
I agree with ADTech.
Attached Images
File Type: jpg mulliganmanFM (2).jpg (194.2 KB, 749 views)
File Type: jpg what I said QUOTE.JPG (18.6 KB, 746 views)

Last edited by rabbit73; 14-Nov-2014 at 7:33 AM.
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Old 14-Nov-2014, 1:49 AM   #69
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Quote:
Well I see. I'm still looking for any kind of patterns with the errors, but I guess unless rabbit has other ideas that only leaves changing out the C2V to something more directional and see if that resolves these signal errors. Is that fair to say (since two 3dB attenuators have been added and the signal errors still occur)?
No, it is not fair to say that. If you look at your original tvfool report you will see that the signals received by the C2V are very strong, with large Noise Margins. This means that you can add a LOT more attenuation before the signals become too weak for the tuners.
http://www.tvfool.com/?option=com_wr...d24362e8886d03

If I were there with you, I would want to add much more attenuation to see if the errors were gone while still having enough signal strength for the tuner. The reason I feel that way is because of the many comments by other Roamio users about it not being able to handle strong signals.

Take another look at this Google search for roamio signals "too hot":
https://www.google.com/?gws_rd=ssl#q...+%22too+hot%22
http://www.epinions.com/review/TiVo_...587068548?sb=1

A DVR that can record more than one channel at a time must have more than one tuner. As ADTech said, there must be a splitter in the DVR to send the signals to multiple tuners. He and I both think that the DVR uses a zero gain splitter, which is a splitter with an amp that adds just enough gain to make up for the splitter losses.

You have already discovered that the TiVo values for SNR are not realistic because they are determined for cable use, not OTA use. It is my opinion that there is a similar problem with the acceptable levels of signal strength for the Roamio. The tuners are probably similar to the tuners in a TV, but the zero gain splitter was designed for cable signals that have a much more narrow range of strength than OTA signals. The engineer who designed the splitter was designing it for cable signals, not OTA signals, which could mean that it was never meant to handle such strong OTA signals.

There are two tests that you can do to see if my theory has any merit.

The first test would be to get several each of 10 dB and 20 dB inline attenuators to add to your attenuator collection. Add more attenuation between the C2V and the AC7 and see what happens to the errors; never mind about the signal strength as long as there is enough left for the tuner to decode the signals for proper reception. You have plenty of NM available before you get down to 0 NM. And you have plenty of dBm Pwr before you get down to -83 dBm, which is where you will reach the "digital cliff."

Earlier you said:
Quote:
So you are taking about inserting a two out splitter after the output of my AC7 combiner (one output to the Roamio and one output to a 2nd televison)? If so, I can try but it may be tough to catch since I don't have 2 TV's in the same room.
I can understand how that might be difficult. Your basement TV is a 60-incher; it is a lot of work to move a large TV. That TV is a Panasonic VIERA TC-P60ST60, which is a nice TV with good reviews.

What I want you to do as a second test is to disconnect the antenna coax from the Roamio and connect it to the P60ST60 to see how it behaves with the same signals that were going to the Roamio. The results might give us a clue about what improvements can be made to your antenna system.

When I have more time, I will give you some more answers.

Last edited by rabbit73; 14-Nov-2014 at 3:03 AM.
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Old 14-Nov-2014, 2:52 AM   #70
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Originally Posted by rabbit73 View Post
Don't give up yet, I still have some more ideas for you to try.

Thanks for the exact coordinates. I ran your FM fool report to see if there were any strong FM signals that might be causing interference. With FM fool there is no link like there is for tvfool reports. I deleted the numbers after the decimal point to protect you, even though the report only shows two digits after the decimal point. I also ran some tvfool reports at different heights, but I will not post them unless you give me permission to do it. They also have truncated coordinates, so the approx. coordinates are pretty far away from your exact location. This is your FM signal report:
.
It is okay to post the other tvfool reports if you think they will help. Let's just not try to reveal my exact location for the whole web to see.
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Old 14-Nov-2014, 3:01 AM   #71
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Originally Posted by rabbit73 View Post

There are two tests that you can do to see if my theory has any merit.

The first test would be to get several 10 dB and 20 dB inline attenuators to add to your attenuator collection. Add more attenuation between the C2V and the AC7 and see what happens to the errors; never mind about the signal strength as long as there is enough left for the tuner to decode the signals for proper reception. You have plenty of NM available before you get down to 0 NM. And you have plenty of dBm Pwr before you get down to -83 dBm, which is where you will reach the "digital cliff.".
So I need clarification here. Are you saying to use enough attenuators to account for 10 or 20dB total? If you are suggesting something else can you link to where I bought from before what I would need?

I have one more 3dB attenuator left that if I would add to what is already in use would total 9dB. So far, the only channel's signal strength affected is 33-1, 33-2, and 33-3.
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Old 14-Nov-2014, 3:08 AM   #72
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[QUOTE=rabbit73;47796

Earlier you said:
I can understand how that might be difficult. Your basement TV is a 60-incher; it is a lot of work to move a large TV. That TV is a Panasonic VIERA TC-P60ST60, which is a nice TV with good reviews.

What I want you to do as a second test is to disconnect the antenna coax from the Roamio and connect it to the P60ST60 to see how it behaves with the same signals that were going to the Roamio. The results might give us a clue about what improvements can be made to your antenna system.

When I have more time, I will give you some more answers.[/QUOTE]

How should I do the comparison? When switching back to the Roamio go back into the Diagnostics menu to check Uncorrected Errors?
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Old 14-Nov-2014, 3:34 AM   #73
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The quote didn't work because you left out the ] after the 47796.

There is no point in switching back and forth, because the signals would have changed by then, which is why I had suggested the two-set comparison which gives you a real-time comparison.

What I'm suggesting now is a second-best test because it would be difficult for you to bring a second set down to the basement, unless you have or can borrow a smaller set.

You already know what the Roamio does with the present antenna system. I want you to see what a TV does with the present antenna system.

Quote:
So I need clarification here. Are you saying to use enough attenuators to account for 10 or 20dB total?
I'm saying keep adding more, a little at a time, and see what happens, until there is no signal left. This is the test in the link in my signature.
Quote:
If you are suggesting something else can you link to where I bought from before what I would need?
I got mine here:
http://www.mjsales.net/items.asp?Fam...266&Cat2ID=125

You got yours here:
http://www.3starinc.com/fam-3_db_in_...uator_pad.html

Quote:
It is okay to post the other tvfool reports if you think they will help. Let's just not try to reveal my exact location for the whole web to see.
They already know it's Ozark, MO from your original tvfool report, and you gave the coordinates of the nearby firehouse in an open forum. I'll be extra careful. I'll just do an extract from the other reports.
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Last edited by rabbit73; 14-Nov-2014 at 8:53 AM.
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Old 14-Nov-2014, 3:57 AM   #74
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Originally Posted by rabbit73 View Post
The quote didn't work because you left out the ] after the 47796.

There is no point in switching back and forth, because the signals would have changed by then, which is why I had suggested the two-set comparison which gives you a real-time comparison.

What I'm suggesting now is a second-best test because it would be difficult for you to bring a second set down to the basement, unless you have or can borrow a smaller set.

You already know what the Roamio does with the present antenna system. I want you to see what a TV does with the present antenna system.

I'm saying keep adding more, a little at a time, and see what happens, until there is no signal left. This is the test in the link in my signature.

They already it's Ozark, MO from your original tvfool report; I'll be extra careful.
So how many 10dB and 20dB in line attenuators do I need to pick up? I'll add my last 3dB attenuator to the C2V while I wait.

i asked what I did about the TV comparisons because I was unsure how to compare since I can have error messages showing in the Diagnostics Menu on the Roamio yet it doesn't cause non-stop picture problems. It can even be a sparse picture problem yet quite annoying.
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Old 14-Nov-2014, 4:08 AM   #75
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Just try different increasing values and see what happens. This is an experiment; we don't know how it will turn out. I can't afford the plane fare to come out there, so we are counting on you to do the experiments.

There should be no harm in adding more attenuation to the point of dropout. The screen will say no signal, which is what it would say if you removed the antenna coax.

Quote:
So how many 10dB and 20dB in line attenuators do I need to pick up? I'll add my last 3dB attenuator to the C2V while I wait.
You should have enough attenuators to equal the NM of your strongest signal ~ 65 dB. That would be two 10 dB, two 20 dB, and the three 3 dB that you already have.

I have to leave. I need to eat because my blood sugar is low, which makes me cranky as a two-year-old who needs a nap.

Last edited by rabbit73; 14-Nov-2014 at 8:52 AM.
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Old 14-Nov-2014, 5:15 PM   #76
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Just try different increasing values and see what happens. This is an experiment; we don't know how it will turn out. I can't afford the plane fare to come out there, so we are counting on you to do the experiments.

There should be no harm in adding more attenuation to the point of dropout. The screen will say no signal, which is what it would say if you removed the antenna coax.

You should have enough attenuators to equal the NM of your strongest signal ~ 65 dB. That would be two 10 dB, two 20 dB, and the three 3 dB that you already have.

I have to leave. I need to eat because my blood sugar is low, which makes me cranky as a two-year-old who needs a nap.
I ordered two 10db, two 20db, and single 6, 12, and 16 dB attenuators that should get here by the Tuesday or Wednesday of next week.

So, I guess what I will do is continue adding attenuators until I lose all channels but Fox. As I add, I will record what I am getting in the DVR diagnostic menu along the way. I will post each recording here. I took a 6dB attenuator reading last night that I will post today and when I get home this evening I will post the 9dB readings (since I added my last on hand attenuator this morning).
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Old 14-Nov-2014, 6:59 PM   #77
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Here are the 6dB Attenuator results:

Channel 3-1 25 dB SNR, 62% signal strength, RS Corrected 0, Rs Uncorrected 0

Channel 3-2 Same as 3-1

Channel 3-3 Same as 3-1 and 3-2

Channel 10-1 29 dB SNR, 72% signal strength, RS Corrected 0, RS Uncorrected 18

Channel 21-1 29dB SNR, 72% signal strength, RS Corrected 0, RS Uncorrected 0

Channel 21-2 Same as 21-1

Channel 21-3 Same as 21-1 and 21-2

Channel 27-1 29dB SNR, 72% signal strength, RS Corrected 0, RS Uncorrected 0

Channel 33-1 25dB SNR, 62% signal strength, RS Corrected 0, RS Uncorrected 90

Channel 33-2 25dB SNR, 62% signal strength, RS Corrected 0, RS Uncorrected 84

Channel 33-3 25dB SNR, 62% signal strength, RS Corrected 0, RS Uncorrected 202

Channel 49-1 25dB SNR, 62% signal strength, RS Corrected 0, RS Uncorrected 0

Channel 49-2 Same as 49-1

Diagnostic readings were taken around 11:30 p.m. on 11-14

Not to compare apples to oranges, but I remembered my Channel Master DVR+ had a signal quality diagnostic so I connected to it on the same TV and got 100% signal quality even on the stations that I got errors on from the Tivo diagnostic. Kind of interesting.

Last edited by mulliganman; 14-Nov-2014 at 7:01 PM.
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Old 15-Nov-2014, 2:04 AM   #78
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Thank you for the 6 dB attenuator test with the Roamio DVR. Please try more attenuation when it is available. Start with 10, then 20, then 30, then 40, and then 50 dB.
Quote:
Not to compare apples to oranges, but I remembered my Channel Master DVR+ had a signal quality diagnostic so I connected to it on the same TV and got 100% signal quality even on the stations that I got errors on from the Tivo diagnostic. Kind of interesting.
Yes, very interesting. What does that tell you? Are you able to make any conclusions based on the CM DVR+ test?

Now, please connect the antenna to the Panasonic TV and tell us about the reception quality as a viewer; never mind about errors. If there were uncorrected errors in the Panasonic, it would affect the reception quality.

Last edited by rabbit73; 15-Nov-2014 at 2:09 AM.
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Old 15-Nov-2014, 3:22 AM   #79
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I now want to talk about grounding. There are three areas that overlap concerning grounding:

1. The NEC requires outdoor antennas to be grounded.
2. Grounding affects the performance of your equipment.
3. Grounding protects you from shock.

NEC REQUIREMENTS

Quote:
I don't know about the grounding blocks.
The NEC requires the antenna coax (two in your case) to be grounded using a grounding block, which they call an ADU, Antenna Discharge Unit.
http://www.solidsignal.com/pview.asp...grounding-lugs

The grounding block should be connected to the house electrical system ground with 10 gauge copper wire.
The antenna mast should also be grounded with another 10 gauge copper wire connected to the house electrical system ground.
This is to drain any static buildup which, in theory, would reduce the chances of a direct lightning strike, and protect you from electrical shock. See attachments 1 and 2.

See these threads:
General Technical & Safety Information
http://forum.tvfool.com/showthread.php?t=901

Grounding Antenna and Dish
http://www.avsforum.com/forum/25-hdt...enna-dish.html

EQUIPMENT PERFORMANCE

Quote:
Your question about the AC operated equipment having 2 wire power cords or 3 wire cords I need some clarification on because I'm not sure what you are asking.
Equipment that has a 2 wire power cord is not grounded by the cord; equipment that has a 3 wire power is grounded by that cord. If a piece of equipment with a 2 wire power cord is connected by a wire with a grounding shield to a piece of equipment with a 3 wire power cord, then the equipment with the 2 wire power cord is indirectly grounded.

Equipment like a tuner, a TV or an AC7 is expected to be grounded when in use to protect it from RF interference.
Quote:
Are you using power strips that have provision for coax grounding? If so, are you using that feature? It's not always a good idea to do that. Yes I have this surge protector in use in the attic (but am unsure about any coax grounding provision):
Your power strip does not have that provision.
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

But this one does:
http://www.amazon.com/Tripp-Lite-TLP...SR8VY9F6CDQD8J
You can see the two coax connectors at the center of the strip. Using those connectors for your antenna coax might expose it to interference from the other equipment connected to the strip and there might be internal surge protection between the center conductor of the coax and the shield that can degrade the signal.

ELECTRICAL SAFETY

When I was calibrating an Apex DT502 converter box for a friend, I received a mild shock when I touched the equipment and the metal strip on the front edge of the counter. The strip was grounded because it touched the metal stove top.



All AC operated equipment has leakage current. Just because you can't feel it doesn't mean that it isn't there. All these pieces of equipment were connected together by a 4-way splitter, and were operating normally in that their individual leakage currents were within safe limits. But, since they were connected together their leakage currents added together, and that's why I felt a mild shock. The setup was using a temporary outside antenna that was not grounded. When I grounded the splitter, the leakage current went to zero.

Having three close calls with electrical shock, I consider the grounding block essential in any antenna system.

Voltage/shock issue
http://www.avsforum.com/forum/25-hdt...ock-issue.html
Getting A/C voltage on converter box's antenna input !
http://www.digitalhome.ca/forum/show...postcount=1022
Equipment Leakage Current
http://www.digitalhome.ca/forum/show...postcount=1025
Proper grounding can protect you from leakage current shocks
http://www.digitalhome.ca/forum/show...postcount=1099
Attached Images
File Type: gif NEC Antenna Grounding.gif (15.2 KB, 305 views)
File Type: jpg Wendell'sDiag.jpg (144.3 KB, 305 views)
File Type: jpg Leakage Current Setup.jpg (140.3 KB, 659 views)
Attached Files
File Type: pdf Leakage Current Tests.pdf (87.7 KB, 301 views)

Last edited by rabbit73; 15-Nov-2014 at 4:04 AM.
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Old 15-Nov-2014, 4:14 AM   #80
mulliganman
Senior Member
 
Join Date: Jul 2012
Posts: 147
I know you said a 10 dB results but I already had the 9dB results before that.

Here they are:

Channel 3-1 24dB SNR, 60% signal strength, RS Corrected 0, RS Uncorrected 0

Channel 3-2 24 dB SNR, 60% signal strength, RS Corrected 0, RS Uncorrected 18

Channel 3-3 24 dB SNR, 60% signal strength, RS Corrected 0, RS Uncorrected 12

Channel 10-1 29dB SNR, 72% signal strength, RS Corrected 0, RS Uncorrected 87

Channel 21-1 29dB SNR, 72% signal strength, RS Corrected 0, RS Uncorrected 0

Channel 21-2 Same as 21-1

Channel 21-3 Same as 21-1 and 21-2

Channel 27-1 29dB SNR, 72% signal strength, RS Corrected 0, RS Uncorrected 0

Channel 33-1 27dB SNR, 67% signal strength, RS Corrected 0, RS Uncorrected 12

Channel 33-2 27dB SNR, 67% signal strength, RS Corrected 0, RS Uncorrected 84

Channel 33-3 25dB SNR, 62% signal strength, RS Corrected 0, RS Uncorrected 222

Channel 49-1 25dB SNR, 62% signal strength, RS Corrected 0, RS Uncorrected 0

Channel 49-2 Same as 49-1

Also saw on tivocommunity.com that RS is Reed Solomon. Digital transmission systems incorporate a scheme called Forward Error Correction which uses Reed Solomon error correction codes

RS Corrected indicates that the demodulator detected a block with an error in it and the RS code was able to correct the error. RS Uncorrected means the error was beyond the capability of the RS code to correct. An uncorrected block most likely will result in a pixelation or a dropout event.
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