 d_lBarsoomPremium,MVM
join:2002-12-08
Reno, NV
kudos:7 | reply to Krellan
Re: [Speed Problem] Lost high frequencies over last few weeks It will be interesting to see if the maxrate gain is maintained through re-syncs.
So possibly a lot of the AM interference inductance is occurring in your drop line wire because it isn't twisted.
You could experiment by grounding your spare pairs to see if it makes any difference. I've always thought that grounding them would make the AM reception worse.
The other thought is to make each spare pair a closed loop by bridging the both ends with the wire splice peanuts. I did this, but I can't really say if it made much difference. |
Krellan
join:2001-06-06
Castro Valley, CA | 
After power cord choke |
I have my own tool that guesses at the max theoretical speed of the line, which is slightly more generous than Deblin's page, so the readings are about 10-200 higher.
I got, after 5 trials:
6300/843
6355/843
6488/843
6519/843
6385/843
After doing that, still connected to the NID (bypassing my Cat 5 wiring), I installed another choke around the power cable to the modem. Fortunately, the power cable was very thin, so I am able to get a lot of turns in the choke. I must have put about 10-12 complete "figure 8" turns on it. Reduced the length of the power cord from 6 feet to 1 foot! I'm now using an extension cord for it, obviously.
Made a substantial improvement. Here's a new graph from the Deblin tool.
Notice the little blip at bin 249. I didn't know my line could go that high! I thought it would have the curve that attenuated down to zero, before then, given my fairly high attenuation reading.
My tool now gives these readings:
6785/843
6363/843
6460/843
The 6785 number got me excited at first, but unfortunately, the improvements didn't hold, as you see by the other numbers.
Here's the numbers from the above graph, that was made when my tool showed the high 6785 reading:
Downstream Current Rate (Reported): 6016
Downstream Maxrate (Estimated): 6528
Downstream Bit Margin (Calculated): 440
Upstream Current Rate (Reported): 768
Upstream Maxrate (Estimated): 1105
Upstream Bit Margin (Reported): 96
Bit tones with notches/missing bits:
bit(s) 38:42 163.875 - 185.4375 KHz
bit(s) 128 552 - 556.3125 KHz
bit(s) 130 560.625 - 564.9375 KHz
bit(s) 138:144 595.125 - 625.3125 KHz
bit(s) 148:149 638.25 - 646.875 KHz
bit(s) 153 659.8125 - 664.125 KHz
bit(s) 155:160 668.4375 - 694.3125 KHz
bit(s) 167 720.1875 - 724.5 KHz
bit(s) 169:176 728.8125 - 763.3125 KHz
bit(s) 181 780.5625 - 784.875 KHz
bit(s) 183:191 789.1875 - 828 KHz
bit(s) 195:209 840.9375 - 905.625 KHz
bit(s) 211 909.9375 - 914.25 KHz
bit(s) 213 918.5625 - 922.875 KHz
bit(s) 218 940.125 - 944.4375 KHz
bit(s) 220:225 948.75 - 974.625 KHz
bit(s) 227 978.9375 - 983.25 KHz
bit(s) 229 987.5625 - 991.875 KHz
bit(s) 234 1009.125 - 1013.4375 KHz
bit(s) 236 1017.75 - 1022.0625 KHz
bit(s) 250:255 1078.125 - 1104 KHz
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