i used to think cable guys have it easy compared to us telco guys but after seeing this man way more to troubleshooting this than dsl and phone, we mostly use tdr and check resistance of your pair to know whether its bad and your capacitive balance this stuff here you have quite a lot more signals you have to check and different test methods i can see definitely massive respect to yall maintenance techs lol
100%. I started my cable career as a very cocky x-network admin. "Hey, I know it all, how hard could it possibly be, it's cable... and why are they providing 3 months of in class training?". When the 3 months was over, I wasn't so cocky AND I was begging for another 3 months of training 😂
The diplex filter in the equipment helps isolate these issues, just as it does chasing upstream noise. The input to the line extender is a 20db test point (imagine it as a 20db tap) and the only echo it will see downstream of it is from the circuitry on the amp itself up to the diplex filter. The most common things that cause echo are corroded connectors, inputs, outputs and splices gone bad. You have to imagine like your yelling down a hallway and you hear your voice echo back. If someone was at other end they would hear you yelling and maybe a bit of the echo moments later from it bouncing back to source and back to you. To continue this laboured analogy. Someone was yelling and there was 3 hallways with screen doors and closing 5he door to one hallway (istop) lowered the echo you could determine what hallway was the main source of the ecjo coming back
Can you or someone explain the difference in a 0 probe vs an I-stop for tracking noise? I typically use the zero for noise but it seems like you use the i stop
I just pull return pads very quickly while monitoring the analyzer and fec/snr polls. Get narrowed down to a few taps and start with the disco drops. But i understand that could be a very low opinion because you technically flash plant in doing so.
MonkiJuan to me they are both equally valuable. I probably use my Gilbert NS9178-1 female test probe more often. But my I stop is more expensive and valuable in tracking noise.
No, ripples are more tricky to track. Usually requires software that tracks the modems and isolates areas and footage of where the incident takes place. Technically each modem is a TDR to tell you the distance to the impairment since the CMTS and modem communicate. There it can determine the distance in time it needs to apply certain equalizing for different plant faults as the upstream travels from the modem to the CMTS. A program tracks that and spits out a footage to the fault. Definitely some sorcery behind it lol.
That’s what’s up! There’s no way to see the echo with an thrilitic 860 meter? Also, that test plunger, what’s the exact name of it and brand? Can it be found online?
So I have a question. If the cable between the 12 tap and the amp was bad causing the reflection wouldn’t it show on the 17 tap as well or was it attenuated enough to not effect signal at the 17 due to the eq and insertion loss of the 2 taps there in the video. Also at the amplifier were you showing an echo? Or simply degraded signal due to the corrosion? If the echo is forward signal reflecting back then how would you determine that the problem was before the amplifier if what you were seeing at the input of the amp was in fact an echo? Wouldn’t it also be safe to assume that the problem could be after the amplifier?
i used to think cable guys have it easy compared to us telco guys but after seeing this man way more to troubleshooting this than dsl and phone, we mostly use tdr and check resistance of your pair to know whether its bad and your capacitive balance this stuff here you have quite a lot more signals you have to check and different test methods i can see definitely massive respect to yall maintenance techs lol
100%. I started my cable career as a very cocky x-network admin. "Hey, I know it all, how hard could it possibly be, it's cable... and why are they providing 3 months of in class training?".
When the 3 months was over, I wasn't so cocky AND I was begging for another 3 months of training 😂
I use the istop to chase noise all day but didn’t realize you could use it this way specifically for echo. Thanks!
Wow! So much great content. Thanks for sharping the knowledge.
The diplex filter in the equipment helps isolate these issues, just as it does chasing upstream noise. The input to the line extender is a 20db test point (imagine it as a 20db tap) and the only echo it will see downstream of it is from the circuitry on the amp itself up to the diplex filter. The most common things that cause echo are corroded connectors, inputs, outputs and splices gone bad. You have to imagine like your yelling down a hallway and you hear your voice echo back. If someone was at other end they would hear you yelling and maybe a bit of the echo moments later from it bouncing back to source and back to you. To continue this laboured analogy. Someone was yelling and there was 3 hallways with screen doors and closing 5he door to one hallway (istop) lowered the echo you could determine what hallway was the main source of the ecjo coming back
Can you or someone explain the difference in a 0 probe vs an I-stop for tracking noise? I typically use the zero for noise but it seems like you use the i stop
I just pull return pads very quickly while monitoring the analyzer and fec/snr polls. Get narrowed down to a few taps and start with the disco drops. But i understand that could be a very low opinion because you technically flash plant in doing so.
Cox?
That gilbert plunger, connected to meter, will the plunger protect the meter from power?
The Trilithic I-stop I used to use had a voltage blocker built-in, so you could plug it into taps that had AC.
i usually get it on bad direct buried dist. the echo/reflections usually get really bad when the cable is about to rot open
Would you recommend a female test probe or a I Stop? This will be my first test probe and I want to make the right choice
MonkiJuan to me they are both equally valuable. I probably use my Gilbert NS9178-1 female test probe more often. But my I stop is more expensive and valuable in tracking noise.
Where did you get the connector to check the seizure screws
It is a test probe our company provides. I believe Gilbert makes them.
Any tips when you are dealing with a Lindsay 8 coupler?
Replace it...lol that's all I got
Ripples and echo, do you troubleshoot them the same?
No, ripples are more tricky to track. Usually requires software that tracks the modems and isolates areas and footage of where the incident takes place. Technically each modem is a TDR to tell you the distance to the impairment since the CMTS and modem communicate. There it can determine the distance in time it needs to apply certain equalizing for different plant faults as the upstream travels from the modem to the CMTS.
A program tracks that and spits out a footage to the fault. Definitely some sorcery behind it lol.
That’s what’s up! There’s no way to see the echo with an thrilitic 860 meter? Also, that test plunger, what’s the exact name of it and brand? Can it be found online?
Alejandro Thillet - Try Gilbert NS9178-1
Curious what you ended up finding that caused the echos?
The cable after that tap was corroded and needed to be replaced. I TDRd it and turned it over for construction to replace it.
So I have a question. If the cable between the 12 tap and the amp was bad causing the reflection wouldn’t it show on the 17 tap as well or was it attenuated enough to not effect signal at the 17 due to the eq and insertion loss of the 2 taps there in the video. Also at the amplifier were you showing an echo? Or simply degraded signal due to the corrosion? If the echo is forward signal reflecting back then how would you determine that the problem was before the amplifier if what you were seeing at the input of the amp was in fact an echo? Wouldn’t it also be safe to assume that the problem could be after the amplifier?
Good question, wish somebody could answer that.
Whats another name for an I Stop?
yes!!! i would love to get that I-Stop probe.
Search “Trilithic I-stop” on google
For my company -14 dBc echo is still considered "passing".
At -14 there is definitely something wrong. Usually find corroded cable.
Thanks!
Thanks for watching Vincenzo! Long time no see!
The Basic Cable Channel switched to nights. Lots of rebuilding and TDRs for techs who find this stuff.
11% battery. The batteries in Viavi meters are horrendous for the price of them.
👏
damn 11percent, you have no fear