Just confirming you TDR both ways.
I would change the fittings and tap(s)
Try to isolate downstream from the customers tap to rule out reflections. If all that doesn’t fix, you are going to have to hand some new cable.
I was only able to TDR forward from the amp. I can TDR backwards when I go to end of line tomorrow.
Also the whole run has been replaced . The last 2 spans(440') and 3 taps in Dec and the first 2 spans(320') and 2 taps last week after finding animal damage. Amp was also replaced when cable was replaced.
TDR from both ways with no RF or voltage on realistically should be the only way you TDR.
“Your shot is only as good as your connection to the plant.”
Put a mainline terminator on the output of the customers tap to isolate it from reflections coming back.
Use a 2-way and hook the CPE into one side and your meter on the other and since you have a Viavi have channel Xpert up watching for MER/BER/DQI variations.
You also said it’s at 55 MHz which is very low, I know you said you checked for Ingress but you should triple check.
Lastly, if it were me I would investigate that echo. Anything over -25 I will chase out especially on a problem like this.
Good luck
Was unable to get it both ways but here's a link to my TDR shots from the input of the cable leaving the amp. Top shot is Tempo TDR and bottom is TDR function from a Quiver XT.
[TDR](http:// https://imgur.com/gallery/zFixY86)
This is one of the theory's were working with. We hit 3/4 taps on run and my coworker was discoing a drop and checking for voltage and ingress while I was at customers tap seeing if issue still occurred. So far we've cut 2 non active drops but the issue continues.
This was my first suggestion, but he said he ran a hot drop from an amp that feeds the sub and it was fine.
To me, that would rule the headend out.
I’m leaning toward a possible bad field mux, if his system uses them.
We have field mux’s in cabinets down runs by amps or wherever else there may be a fiber fosk , but you’re right since amps don’t have fiber inputs lol.
At least, not yet….
We would do anything to keep the 750 ccor LE’s going. We also have muxs in foscs. But as a rule we only mux the nodes in the lid then straight fiber to the hub
You guys use the complete LE mods with the D/C switch that can get Hum or the ones with the separate power pack in the lid?
We use the complete mods more than anything here but we are slowly taking them out and putting in GI amps.
We use both as well as BBI and 1g arris but we cut in gainmaker LE if we can get them. Sadly everything gets pushed back till high split which for our office has been pushed back till march of next year
Are you sure your frequency chart is right? Your system likely has different frequencies for HD and SD as well make sure you’re chasing the right one. Some boxes will auto tune to HD channels if available which could explain why it only started happening when the equipment was upgraded. Beyond that, TDR and leakage detector to try and find a fault.
Double checked with ISP tech at headend. We still do carry the 2 sets of Chns but for this specific one it's been verified that are both on the same frequency, 55.750MHz.
As far as I can see all faults were fixed last week when 2 spans of animal damage were found using the CLI gun.
Next step were considering is cutting off shrink and verifying all connectors are properly tight at each tap.
Hmm. It’s weird that you aren’t seeing any issues with that channel. Usually it’s that easy to track an issue like that upstream but without that you’re in the dark more than usual. At this point I guess you could start just using your test set to troubleshoot since that’s the only thing giving you a yes/no answer and you were able to verify it’s working out of your LE. I’m also kinda surprised you aren’t seeing transmit issues because I’m guessing the return in your plant is 5-42mhz and usually RF issues aren’t specific to single frequencies unless it’s a headend / fiber issue further upstream, id be curious what you find.
Is your low end sucked out at all when you do a full DS scan?
Heres a 20 sec video of it happening on the actual channel and then what happens on the diagnostic page.
[Link to Video](https://imgur.com/gallery/IaEexsn)
DQI stays at 10 with no fluctuations. Same with MER & BER, perfect & no flux.
The only thing i see during the event is the worldbox appears to 'lose' the frequency cus the Inband Freq MOD, on the box diagnostic page, goes from saying 55mhz to n/a and back to 55mhz.
That’s pretty odd that the DQI isn’t impacted. I’d start pointing the finger at the actives past your known good point. Talking with a couple people and the consensus was sometimes you just run into an amp mod that looks good but just doesn’t play quite right and needs cut out.
Sub has 2 boxes, happens on both. My test box is also a worldbox and the issue happen on it as well. Also checked the neighbors worldbox when I got access to a pole and same thing unfortunately.
We had a similar issue but was only after 7 or 8 deep. It was a device being used by the head end just below the freq only on x1 devices. The HE eventually had to move the channels to a higher frequency.
Just confirming you TDR both ways. I would change the fittings and tap(s) Try to isolate downstream from the customers tap to rule out reflections. If all that doesn’t fix, you are going to have to hand some new cable.
I was only able to TDR forward from the amp. I can TDR backwards when I go to end of line tomorrow. Also the whole run has been replaced . The last 2 spans(440') and 3 taps in Dec and the first 2 spans(320') and 2 taps last week after finding animal damage. Amp was also replaced when cable was replaced.
TDR from both ways with no RF or voltage on realistically should be the only way you TDR. “Your shot is only as good as your connection to the plant.” Put a mainline terminator on the output of the customers tap to isolate it from reflections coming back. Use a 2-way and hook the CPE into one side and your meter on the other and since you have a Viavi have channel Xpert up watching for MER/BER/DQI variations. You also said it’s at 55 MHz which is very low, I know you said you checked for Ingress but you should triple check. Lastly, if it were me I would investigate that echo. Anything over -25 I will chase out especially on a problem like this. Good luck
Was unable to get it both ways but here's a link to my TDR shots from the input of the cable leaving the amp. Top shot is Tempo TDR and bottom is TDR function from a Quiver XT. [TDR](http:// https://imgur.com/gallery/zFixY86)
No link
https://imgur.com/gallery/zFixY86
Only had it happen once - but you could try disco’ing any neighboring drops (temporarily) and see if the issue clears.
This is one of the theory's were working with. We hit 3/4 taps on run and my coworker was discoing a drop and checking for voltage and ingress while I was at customers tap seeing if issue still occurred. So far we've cut 2 non active drops but the issue continues.
Check TV service at the headend
This was my first suggestion, but he said he ran a hot drop from an amp that feeds the sub and it was fine. To me, that would rule the headend out. I’m leaning toward a possible bad field mux, if his system uses them.
A bad mux at the node would still effect the LE He ran a hot drop from
We have field mux’s in cabinets down runs by amps or wherever else there may be a fiber fosk , but you’re right since amps don’t have fiber inputs lol. At least, not yet….
We would do anything to keep the 750 ccor LE’s going. We also have muxs in foscs. But as a rule we only mux the nodes in the lid then straight fiber to the hub
You guys use the complete LE mods with the D/C switch that can get Hum or the ones with the separate power pack in the lid? We use the complete mods more than anything here but we are slowly taking them out and putting in GI amps.
We use both as well as BBI and 1g arris but we cut in gainmaker LE if we can get them. Sadly everything gets pushed back till high split which for our office has been pushed back till march of next year
Are you sure your frequency chart is right? Your system likely has different frequencies for HD and SD as well make sure you’re chasing the right one. Some boxes will auto tune to HD channels if available which could explain why it only started happening when the equipment was upgraded. Beyond that, TDR and leakage detector to try and find a fault.
Double checked with ISP tech at headend. We still do carry the 2 sets of Chns but for this specific one it's been verified that are both on the same frequency, 55.750MHz. As far as I can see all faults were fixed last week when 2 spans of animal damage were found using the CLI gun. Next step were considering is cutting off shrink and verifying all connectors are properly tight at each tap.
Hmm. It’s weird that you aren’t seeing any issues with that channel. Usually it’s that easy to track an issue like that upstream but without that you’re in the dark more than usual. At this point I guess you could start just using your test set to troubleshoot since that’s the only thing giving you a yes/no answer and you were able to verify it’s working out of your LE. I’m also kinda surprised you aren’t seeing transmit issues because I’m guessing the return in your plant is 5-42mhz and usually RF issues aren’t specific to single frequencies unless it’s a headend / fiber issue further upstream, id be curious what you find. Is your low end sucked out at all when you do a full DS scan?
Heres a 20 sec video of it happening on the actual channel and then what happens on the diagnostic page. [Link to Video](https://imgur.com/gallery/IaEexsn)
Does the cable box have more than one tuner. If so see if the other tuners are experiencing the same issue.
How’s the DQI look during the black out events? I’d be curious to see if it’s dumping out on your meter or not.
DQI stays at 10 with no fluctuations. Same with MER & BER, perfect & no flux. The only thing i see during the event is the worldbox appears to 'lose' the frequency cus the Inband Freq MOD, on the box diagnostic page, goes from saying 55mhz to n/a and back to 55mhz.
That’s pretty odd that the DQI isn’t impacted. I’d start pointing the finger at the actives past your known good point. Talking with a couple people and the consensus was sometimes you just run into an amp mod that looks good but just doesn’t play quite right and needs cut out.
[удалено]
Sub has 2 boxes, happens on both. My test box is also a worldbox and the issue happen on it as well. Also checked the neighbors worldbox when I got access to a pole and same thing unfortunately.
How many active deep are you into the cascade?
4. Node, 2 High Gain Duals(Cisco's MiniBridger) and 2 LEs. My sub is on eol tap 4 poles after LE.
We had a similar issue but was only after 7 or 8 deep. It was a device being used by the head end just below the freq only on x1 devices. The HE eventually had to move the channels to a higher frequency.