justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
 ·AT&T Midwest
| reply to lev
Re: Any 5100b technician page DMT/SNR data experts
Here's a one line summary:
SBC does not have the ability or expertise necessary to troubleshoot RF interference problems.
You're SOL if you have an RF interference problem on your DSL or telephone line!
Here's a summary of the epic:
SBC tried swapping telco lines three times. Each time the F1/F2 pair was swapped, they managed to find an increasingly worse line! Isn't that great! I went from a 5.4mbps max attainable line to 3.5mbps max attainable to the current 3.0 max attainable line. All three lines exhibited the same noise characteristics. Peridoically, during weekday mornings, the line suffers from noise that causes anywhere from a 3.0dB loss of SNRM (11.5 to 8.5) to a 7.5dB loss of SNRM (10.5 to 3.0.) For 40 days, when the problem first started occurring, this same recurring source of noise was strong enough to cause my DSL modem to lose sync every time the noise occurred.
I personally have gone many different routes attempting to troubleshoot the DSL problem. I have used 4 different modems now (two SpeedStream 5100b, SpeedStream 5660, SpeedStream 5360.) I have tried multiple CAT 5 cables. I have eliminated all inside wiring down to a CAT 5 cable running in a window to 1 telephone and 1 DSL modem for weeks now. I have a SBC provided Home Run (CAT 5) that connects directly to 1 telephone and 1 DSL modem. No other telephone wires are in use. No other telephones are connected.
I have tried telephone surge protectors. I have tried multiple DSL microfilters. Nothing changes the noise problem.
Sometimes, the noise problem manifests in thousands of CRC errors in a short amount of time. The noise occurs at different times on weekends and holidays, but is very consistently repeated during the week: 40-45 minutes where DMT bit bins are reallocated and SNRM drops significantly across the download portion of the lower frequency spectrum.
From SBC Direct, the last bunch of responses have all been related to getting me to attempt to find the source of RF interferece. Suggestions have ranged from using an radio frequency spectrum analyzer, an AM radio, to CB radios to attempting to coorrelate TV interference with the DSL problem... to even talking with my nearest neighbors in an attempt to find out if any of them are seeing any telephone, TV, DSL, Sattelite TV, Cable or radio interference at the same times of day that I am. All of these suggestions require an absurd amount of my time and money to troubleshoot and attempt to isolate... especially when the problem occurs during times of day that I am normally at work, not at home!
The whole Cable TV suggestion came in because I recently found a cable modem filter laying in my backyard. A "ARCOM WHP-5/13" coaxial signal filter was laying in the bushes behind my house. It's a "return path filter".
»www.arcomlabs.com/pdf/window.pdf
The telephone issue came into play because my directly West neighbor has been complaining to SBC for months about static, noise and crosstalk on her telephone line, but she's afraid to have them come out because they keep threatening her with "fees". She's not so happy with that idea because the problem is intermittent and she just knows that they'll come out and look at the line when the problem is not occuring. (But I haven't gotten data from her to coorelate her problems with mine yet.)
My latest troubleshooting attempts on my own behalf are in attempting to use a Formac Studio DV NTSC TV capture device to automate the collection of Channel 2 & Channel 5 TV interference that I am experiencing. At different times and durations during the day, Channel 2 and Channel 5 experience the same kind of interference: a poor TV signal with lots of interference. At other times of the day, I get dang near perfect Channel 2 and Channel 5 reception. It's frustrating. I even have two antennas available that I am sampling from: my outdoor chimney mounted antenna and an indoor RadioShack Digital HDTV amplified antenna. It's very hard for me to try to compare the data I'm capturing from the different antennas and come up with conclusions that may or may not be related to the DSL noise problem.
The Channel 2 & Channel 5 interference has become significantly worse ever since I changed the grounding on my outdoor chimney antenna. In the next few days, my father and I are going to attempt to see if his CB radio is able to cause interference on my TV. (I doubt it.) We're also going to disconnect the new grounding wire that we added to see if that changes the interference level. We're also going to reposition the outside antenna to see if that helps eliminate the Channel 2 & Channel 5 interference.
I have eliminated all electronic devices from my house as being the source of interference. I did this one day by turinging off absolutely every appliance and device in the house (except for a computer, and the DSL problem still occurred. I haven't tried this for the Channel 2/5 interference I'm seeing yet.
The funny thing is that periodically, during the day, Channel 2/5 will go from being very fuzzy to very clear, to fuzzy to clear, back to fuzzy for a long time in a 35 second sample that I just took. (118MB of raw video) Sometimes, a ghost appears... sometimes it's just a lot of static.
To do some DSL regression testing, I returned the 5100b that I borrowed from my brother and even set up his computer to start logging 5 minute snapshots during the day. He is connected to a different CO and is over 5 miles East-Northeast of my location. He experiences no sporradic RF interference on his DSL line. I obtained a new 5100b from SBC. This new modem captures the noise problem exactly the same way as the other 5100b modem I was borrowing.
So, in short, I'm attempting to correlate the Channel 2/5 interference with the DSL interference, but I'm pretty sure that's not going to prove anything at all. Coordinating with my neighbors to find out about their interference problems may be the only course of action I have in getting the FCC to come out and investigate the problem.  Has anyone dealt with the FCC regarding interference before?
--Steve |
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lev
Napoleon is always right
Premium,Ex-mod 2002-08
join:2001-05-30
Chicago, IL
clubs:  | reply to justbits
Can you summarize, in two paragraphs or so, where we are now? This thing reads like an epic.  |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
1 edit | reply to justbits
My dad spotted the neighbor's antenna at Menards. $70
Phillips Magnavox
MANT901
51 elements
VHF 200 miles
UHF 80 miles
FM 150 miles
Digital & Satellite compatible
I've got a NTSC video capture device. I've got some samples of how great the signal looks at 7:49 am this morning, compared to 12:52am this afternoon. The differences are amazing.
10.5 SNRM on 5660 modem:
 200507080749···snap.zip 333905 bytes
(200507080749chimneysnap.mov)
8.5 SNRM on 5660 modem:
200507081244snap.zip 329365 bytes
(200507081244snap.mov)
--Steve |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
| reply to justbits
I just found out that the reason why I'm down to 3.0 max attainable is because they switched my F1/F2 pairs on Thursday, in an attempt to solve the noise problem.
That's three pairs of wire that exhibit the same noise problem. Because the noise isn't causing a loss of sync anymore, I'm trying to get back the 5.4mpbs max attainable pair.
--justbits |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
2 edits | reply to Riss_Centaur
Riss: Thanks for digging up the information on the splitter!
I just finished running a brand new grounding wire to my TV antenna.
Menards copper grounding spire
Radio Shack 40 ft Aluminum Grounding Wire
I sanded off the wire terminals that connect to the antenna to the RG6 cable.
I also added a 25 foot run of cable to completely remove how taught the antenna cable used to be. I also used rubber outdoor tape to wrap the junction of the antenna to 25 foot cable run.
Today, I ran a new grounding wire to my TV antenna.
Menards 5 foot copper ground steak
Radio Shack 40 ft Aluminum Grounding Wire
I sanded off the wire terminals that connect to the antenna to the RG6 cable. I also added a 25 foot run of cable to remove how taught the antenna cable used to be.
It's amazing. I've always had static on Channel 2 & Channel 5. Even before today and at 12noon and 3pm. But, I'm not an avid TV watcher of those channels at all times of the day.
The change was made between 3pm and 4pm.
At 4:00 til 4:45, I had periodic spurts of extreme interference on Channels 2 OTA and Channel 5 OTA. (Over the air) It would be very noisy for a while, disappear for a few minutes or seconds and then reappear.
After 5:00pm or so, Channel 2 OTA and Channel 5 OTA show up with absolutely no interference!
At 8pm (now), the interference is back. (hrmm)
I'm going to start watching 2 & 5 to see if the high periods of interference coorlate with my DSL noise interference.
I just recalled that a few months ago (not sure when) my kitty-corner backyard neighbor installed a brand new roof top antenna. I don't believe he has his antenna grounded. It's also one I've never seen before. It's very very large. Even bigger than the biggest that Radio Shack sells.
Here's what my neighbor's antenna looks like.
Has anyone seen an antenna like this before?
See that telephone cable, where it runs down the pole into the ground. That's where my telephone wire goes about 300 feet underground to a cross connect box on a side street (that's a F2 pair). From the cross connect box, it goes directly to the CO (that's a F1 pair.) In the air from my house to the pole, I estimate that's between 130 and 150 feet. I'm pretty darn close to my neighborhood cross connect box.
I can see my neighbor's RG6 cable, but no grounding wire from this angle.
I'm probably going to stop by the neighbor and ask what model/brand it is. Then I'll ask if he's got it grounded and the RG6 cable surge protected. (It's best to have both, right? I do.)
--justbits
[edit: added note about f1 & f2 pairs] |
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Riss_Centaur
Mod'taur - - - - 4 On The Floor.
Premium,MVM,Ex-Mod 2005-07
join:2004-01-20
other
clubs:
1 edit | reply to justbits
That splitter is a corning/siecor.
»www.corningcablesystems.com/web/···5-EN.pdf
Fairly standard in-NID pots splitter-filter.
-Riss
--
I have a plan so cunning you can pin a tail on it and call it a weasel! |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
1 edit | reply to misskaz
Lucky me. A bunch of managers and techs were on site yesterday for a vendor meet. (SBC Ameritech-POTS + SBC ASI-DSL). Of course, they blamed the problems on my wiring AGAIN. I had a directly connected home run CAT 5 cable into the DSL modem and a regular microfilter in the NID that only provide POTS on a separate CAT 5 cable. They "replaced" those. They gave me an in-NID microfilter and a home run. The home run is a single, white outdoor CAT 5 cable into a simple plastic box marked "DSL" and "Phone". One pair of wires is DSL. One pair of wires is POTS. The in-house jack on the end of the home run has two CAT5 RJ45 8-pin connectors on it (it's not your the RJ11 6-pin jack that you'd normally expect.)
The in-NID microfilter seems to be signifcantly worse than the in-house ones that they provide! Isn't that great?
I used to get 3.2mbps max attainable. Now I'm down to 3.0 max attainable.
Best part is *drum roll please* the noisy signal still occured this morning.
I'm trying to see if I can get SBC to replace my F1 & F2 pairs with the previous ones that I had so I can get back to doing 3008/512. (The 5.4mbps+ capable wires.)
Here's a picture of the in-NID filter that I got. I'm probably going to see if I can figure out how to bypass it and run the pure POTS+DSL signal on one the DSL wire pair into my own in-door filter or even just run the customer side DSL+POTS wires directly into the modem.
Can anyone find who makes this device and what the internal wiring of it is? Is it an in-NID microfilter? It seems like it's gotta be.
SPS-SA1-SR1
104510-1A
E112187/4184
Communication Circuit Accessory
--Steve |
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misskaz
@chcgil.ameritech
| reply to justbits
We're on the north side of Chicago - Lawrence and Ashland - but not as far west as you are. Our exchange is 773-275, so we're not in the same central office.
Apparently our internet connection has been worse than I previously thought - I'm on a laptop in the living room so I'm rarely looking at the modem, and I get much of my fill of the internet at work. According to my boyfriend, who is on the internet at home much more than I am, the connection was going out so often recently that we could barely keep the connection going for more than 1 hour.
I say "was" because today I woke up to find our internet not working and our voice line completely dead - no dial tone. I went out to the NID and couldn't get a dial tone there, at the one that had our apartment number on it. I called SBC and they must have detected trouble on the line, because they sent out a tech. (Although it turns out the jack at the NID with our apartment # and no dial tone wasn't actually the one for our apartment - isn't that helpful?)
After some testing on the jacks in the apartment, the tech found that a busted jack in our den that we never used had a broken connection, which somehow was screwing things up for the working jacks in the other rooms. Once he fixed that, our voice came back and our DSL has been working for an hour now with no problems. I'm optimistic, although I think my boyfriend has been so frustrated with all this lately that he still thinks our connection will drop.
Now we just have to wait to see if 1) the DSL keeps working and 2) we get charged for that tech visit despite subscribing to line-backer.
Good luck to you, justbits. I too admire your patience. |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
| reply to klevin
I wrote some bash shell scripts.
I gather the technician data from the 5100b.
I parse out the SNRM & DMT data.
I put them into separate files.
I feed the data into gnuplot.
I gather and plot the data periodically (at least every 5 minutes) using a cron task.
I'm doing this on MacOS X, but I suppose it would be trivial to port to Linux or Cygwin.
--justbits |
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klevin
join:2004-07-26
Takoma Park, MD | reply to justbits
how do you get those nice graphs (spectrum analysis?) |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
| reply to Old_Grouch
I'm being patient because I'd rather have the problem completely fixed correctly, rather than quick fixed poorly, like they did when I was switch to a significantly poorer quality pair of wires on June 7th. (The change was from a pair capable of 5.4mb/1080 max attainable, to 3.2/600 max attainable.)
After reviewing yesterdays data and the day before, I think I might be seeing a larger trend across the entire day.
The lower download frequencies have significant SNRM degredation from 7am til just before 5pm. There's also typically a spurt of 100-300 CRC errors earlier in the morning too. Can't do it today or tonight, but sometime soon, I'm going to be reviewing the entire day's data for the last few weeks to see if I see the general trend during "business hours". I'd laugh if the hours match those of a local bank.
The "bit migration" problem occurs once or twice each morning. If it lasts for 45 minutes, it will usually only occur once. If it lasts for 35-40 minutes, it will usually occur twice. I need to reanalyze my data, but that's what I think I'm seeing.
I like your 3x5 crazy idea cards. Actually, a co-worker of mine who was having DSL problems proposed that some of the ASI telephone people have an 8-ball or a dart board that is weighted heavily on "inside wiring", "squirrels chewing on the wires", "high performance errors", and "bad modem". I would say "inside wiring" was the one that they hit me with the most.
--justbits |
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Old_Grouch
Don't just sit there silly DO something
Premium
join:2004-05-26
Greenwood, IN
clubs:
·AT&T Midwest
| reply to justbits
Re: Any 5100b technician page DMT/SNR data experts?
justbits
Never, ever in my life has anyone accused me of having patience like yours. I'm impressed.
No technician qualities here - - but something sticks in my mind from the reading. On page one, Riss noted that the charts seem to have a distinct sine wave pattern to them and there was discussion that that pattern could be caused by a number of things - including - T1's. And, your line runs in a bundle/group/whatever with about 9 T1's.
If you keep 3X5 cards with crazy ideas, make one out for me:
- can T1's cause a sine wave noise pattern like you have captured?
- how many of the 9 T1's that you are partnered with run to businesses that are likely retail with 24 hour/day operations and point of sale terminals that upload sales/download prices/upload inventory data?
I keep looking at the possibility and the times and can almost see a 7X24 business that has a home/regional office that queries for sales each morning while providing ordering info; and does inventory/pricing each afternoon five days a week with some (limited) spill-over to the weekend. If you've got one of those on the other end of one of the 9 T1's and they have recently added or swapped a point of sale terminal.....
I've never been any good at guessing the date a baby will be born but for other things - -
hope my post isn't too distracting. GOOD LUCK
--
Keep your eyes open for my pills...I MUST have my meds. |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
| reply to misskaz
Re: Any 5100b technician page DMT/SNR data experts
The SpeedStream 5360 provides absolutely no data to the customer. If it does, it's very undocumented.
A 5660 or a 5100b would be better. If you recently upgraded your service, you could call back and ask to see if they can get you a new 5100b modem for just shipping. ($6-$9 or so)
What area of Chicago are you in? If you're within 3 miles of River Grove, that would be very interesting and possibly related. If you're close to Cumberland & Montrose, that's an even higher possibility of being the same problem!
Which CO does your telephone number come out of?
Go to »/coinfo
Put in the area code & exchange of your telephone number.
If the results are "RVGVILRG", bingo, your central office is the same office as mine.
RVGVILRG serves:
708-452 708-453 708-456 708-583 708-695
847-288 847-451 847-455 847-260 773-625
773-658 773-589
My neighborhood is 773-625 and 708-456.
My next door neighbor's been complaining that for the last few months, they've been hearing static pops and cross talk (other people talking) while she's been on the phone during the day. I told her to start logging when the problems occur to see if they coorelate with my problem.
You might go back in your Network Interface box and loosen and re-tighten some of the wires. Sometimes they come loose, sometimes, they are overtightened.
The biggest pain in the butt that you'll have to go through is bending over backwards to prove the problem is not your inside wiring. The easiest way to do this is to hook the DSL modem directly into a microfilter at the NID and only hook up one phone. If you have a wireless router that reaches your apartment, that'd be good. If you can show the problem exists, even at the NID with a minimum amount of wires, then it's not your inside wiring.
When you hook up wires, do not use any flat telephone cords. Use round cords. Yes, some of the microfilters have flat cords... that's ok, because they're usually 4 inches long. If you have any CAT 3 or better cable and a crimping tool, make your own short run of wire. That would be the most ideal.
As for linebacker, you should talk to the POTS repair service, not the DSL Tier 1 problem phone number.
Make sure you don't have any television cables or power cables running near your telephone cables too, if possible.
--justbits |
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armyrebel4
Dream Chaser
Premium
join:2002-01-08
Springfield, IL
·AT&T Midwest
| reply to justbits
"For the purpose of constructing and maintaining such lines of telegraph or telephone, the parties in interest may set the necessary poles or posts on which to place the wires and insulators of such lines, in any of the public streets, highways or alleys, or in any private road leading to such highways, streets or alleys outside of the incorporated cities, villages or towns in this state along which such lines may pass: Provided, such poles or posts shall be placed along the boundaries of such highways, streets, or alleys, at such distances therefrom as the authorities having control thereof may direct. And provided further, that the wires necessary for such lines shall not be less than fifteen feet above the ground along such boundaries, and not less than twenty feet at any public or private crossing, and shall be so placed as not in any manner to interfere with such crossing.
Any person who shall unlawfully and intentionally injure, molest, or destroy any of said lines or the material or property belonging thereto, or shall in any manner interfere with the proper working of such lines, shall on conviction thereof, be deemed guilty of a petty offense and fined not exceeding $100. The fine shall be recoverable in the circuit court; Provided, that prosecution under the foregoing provision of this section shall not in any manner prevent a recovery by the person or persons entitled thereto, of the amount of damages done to such lines."
That's state law. Unless there is some kind of radiation leak lol, get cable man it's not worth the hassle.
--
“True individual freedom cannot exist without economic security and independence. People who are hungry and out of a job are the stuff of which dictatorships are made.”- FDR |
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misskaz
@chcgil.ameritech
| reply to justbits
I unfortunately can't offer any help, but I feel deja vu reading your posts. We have had very similar problems with our SBC DSL for months now. (We live in Chicago, too.)
Lately, we've been losing our DSL connection on a very regular basis - close to once a day at this point. It used to be once every few months, and has been happening more and more often. Every time we lose the connection, I have to reset and set up our router all over again or I can't connect to the internet wirelessly with the laptop. It's incredibly frustrating, to come home from work and need to get stuff done only to find that the internet's out AGAIN and you have to unplug things and plug them back in and re-do all the router settings.... argh! Today even that didn't work - connecting the modem directly to the computer gave me a "limited or no connectivity" warning about the connection.
We are also faced with a lot of noise on the voice line, although it's cleared up somewhat since my boyfriend found and cleared out a really dense spider web/nest from our network interface box.
I can't say we've done anywhere near the techy troubleshooting that you have (can I do that data capture with my SpeedStream 5360?) but yet another call to Tier 1 tech support at SBC this evening has introduced me to the possibility of interference causing the problem. Previously we thought it was just the ancient lines in this apartment building - and it may well be that's the case after all.
Honestly, I'm really close to cancelling SBC altogether, phone and internet, and getting a cable modem and VoIP. Oh yeah, have I mentioned that even though I've paid for their "line-backer" service for 3 years, which is supposed to cover tech visits even if the problem is the lines inside the house, SBC won't come out because they claim it's my landlord's responsibility. Funny how they didn't mention that when they asked if I wanted to pay an extra $5 a month for the service.
Anyway, good luck and I'll be following your threads to see if you get anywhere. |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
| reply to joewho
It is extremely unlikely that an animal or insect would cause radio frequency interference that repeats for a pretty particular duration (45 minutes) during the week and at different times on weekends and holidays.
The more likely candidates we're exploring right now are improperly filtered coaxial cable TV cables on the utility pole, the neighbor who had the improperly installed satellite TV hookup, or possibly some AC/DC motor, like a hot tub, a spa, or a excercise machine that's placed too close to telephone wires. (All of these candidates are not present within my home.)
Just thinking about it... if the person who attached their dish to the utility pole wasn't smart enough to properly install their satellite dish, it's also likely that they also do not have proper cables or filters attached to that device to prevent them from causing excessive RF interference.
--justbits |
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joewho
Premium
join:2004-08-20
Las Vegas, NV | reply to justbits
Maybe there's a wasp nest in the box on the pole... |
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justbits
More fiber than ATT can handle
Premium
join:2003-01-08
Chicago, IL
·AT&T Midwest
| reply to chris123
I have tried swapping microfilters. I've had the microfilter located in the NID and inside my house. Since I've gone crazy trying to eliminate potential sources of interference, all I have is one wireless telephone hooked up to one microfilter. A whole house microfilter wont make any difference in this case.
--justbits |
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chris123
join:2002-07-23
Highland, IN
| reply to justbits
Have you tried changing out your filter, or installing a proper whole house splitter? Check the for sale forum if you need to buy one.
I'm just shooting in the dark here, but I've heard other people say they go bad at times.
--
see my SBC Review @ »Review of AT&T Midwest by chris123 |
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AlEinstein
join:2004-10-08
Hughson, CA
| reply to justbits
Port change is a good idea. I'm still seeing a flucuating noise margin though. Bad ports usually throw errors and less frequently attribute flucuating noise.
I'm not into beating dead horses, or any state of a horse for that matter, but how about a new protector for sure and then a possible pair change after the port change??? Seems like not much effort in the interest of being thorough.
Einstein, OUT
Keeps us posted.
Bits, God bless ya, but you're darn close to making this into rocket science! Love those data report posts! I think my scroll bar is about worn out.
Take care, good luck |
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