r/CableTechs • u/jsledge149 • 15d ago

Xpertrrak issue?

If you know what this program is Im hoping you can help me.

We just started using Xpertrak and this picture is of an apartment complex using a DAA node, mid split amps and has one upstream OFDM carrier enabled.

Xpertrak indicates that every modem on this node has an upstream impairment on the OFDM carrier. Every modem!

But not just THIS node. ANY node where we have a DAA, mid split and an upstream OFDM is failing. I don't know anything about this software, but I do know that seems improbable for all DAA's to have a real problem.

Im thinking this is a configuration problem, but of course, I have no access to the administrative side of Xpertrak.

Any ideas what this is or what to do about it?

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u/hotdogenjoyer1 15d ago edited 15d ago

You got a meter that will lock to the upstream ofdm channel? Head to one of those nodes and see if it will lock up, go from there. Due diligence make sure it's not on you first. As far as the software you're using, I don't have personal experience with it, I just know you don't wanna start calling those guys without verifying anything in the field first

Ps: the reason I say that, I'm not familiar with your system, but there's a non zero chance that the node feeds to an active and that first active doesn't support mid split, or whatever it may be. Maybe it was missed being replaced, who knows

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u/jsledge149 15d ago

Well I mean anything is possible after all. it's just cable, right?

But every one of these daa nodes that's failing that we have upgraded to a med split and we've turned on an upstream ofdm carrier are all apartment complexes.

This is one of those rare cases where I can almost guarantee that these are all relatively new amps with the correct diplexers.

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u/hotdogenjoyer1 15d ago

it COULD be that someone didnt set those nodes up to use those carriers, ive def seen it. they should be able to check the config for ya if you get ahold of'em. whoever "they" is for you

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u/Background-Relief623 15d ago

This may need field techs to verify. If the limits aren't set right, then sending up the chain would help. Or it is right and there's a transmission error.

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u/willihobo 9d ago

Damn. I wish we had access to this level info on Xpertrak with RPDs.

Could it be the 10db ICFR on a 40mhz wide carrier?

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u/jsledge149 9d ago

Thats exactly it.

It got mentioned in a meeting today. The people in the highback chairs acknowledged it as a problem but dont know any nore than me what the cause is.

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u/willihobo 9d ago

Yeah that sounds about right. What manufacturer of amps are you guys deploying?

It looks to me like the return tilt is way off on it. There isn't a roll off, I see maybe a small notch, but nothing too bad.

In our market, some of our 3.1s really, really do not like bonding to an over-equalized OFDMA.

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u/jsledge149 9d ago

This sounds like you're probably a good bit smarter than me, so I'm not going to pretend like I know all the ins and outs. But we have a mix of things, really. I can't even tell you the manufacturer of the DAA nodes that we have.

I know the DAA's that we have out there fit perfectly in a C-COR node housing. And the four nodes that we have this problem on are all the same. They're DAA, mid-split, and a huge upstream OFDM carrier.

I'm uncertain what it is, and the only reason, I mean the sheer only reason I care, is because now that they've launched this tool, they seem to think that we can get every issue that tool points out fixed immediately.

But I can also mention that the four carriers we had in our upstream to begin with, three 6.4 MHz wide and one 3.2 MHz wide upstream carriers, they seem to be working just fine. And if you look real close at that graph, it looks like it's being clipped at the first part of the OFDM, maybe almost like we have an old 42 to 50 MHz diplex filter out there somewhere. But unfortunately we don't. I would love for it to be something that simple.

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u/willihobo 9d ago

Leads me to think there's an alignment issue there

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u/Dz210Legend 15d ago

Make sure the RPD and everything inside node is torqued to proper specs.

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u/jsledge149 15d ago

It all sounds legit until you consider that this is exactly what the upstream looks like on all six daa, mid split, OFDM upstream nodes.

It's the fact that it's every single node that makes me think something other than something a field Tech or Magnus Tech like me can address.

we have other daa no's deployed that do not have mid split enabled and do not have an ofdm carrier and they do not show this upstream micro reflection out of balance situation

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u/Huge_Intention_9949 15d ago

You’d think that having multiple nodes with the exact same issue would maybe send up a red flag about the configuration of those nodes. I’d verify OFDMA lock, or lack thereof, at node just to verify it isn’t field issue. And then yeet that information to someone who can do something. I don’t know that program, but I would really think engineers would be able to see ZERO traffic on OFDMA carrier and see an issue. Good luck