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Thread ID: 23021 2002-08-05 11:18:00 Ground Noise Levels Sam H (525) Press F1
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68399 2002-08-05 11:18:00 What would be a good average ground noise level?

Telecom said I had a level of 58 which was normal.
Sam H (525)
68400 2002-08-05 11:23:00 > What would be a good average ground noise level?
>
> Telecom said I had a level of 58 which was normal.
>

you might want to qualify what you mean...the ground here is very quiet, it has only a few earthworms stirring.

do you mean background noise on a phone line? and are you talking dB, and is that dB log10 or just dB??
godfather (25)
68401 2002-08-05 11:29:00 Well if you are winding up the stereo - the maximum permitted noise at your boundary is something in the region of 40dBA . The exact figure - so I'm told - is in the Resource Management Act somewhere .

I don't think it specifies whether you have to be lying on the ground or half way up a ladder at the boundary though . . . .
Heather P (163)
68402 2002-08-05 11:32:00 remind me never to live nextdoor to you Heather...... godfather (25)
68403 2002-08-05 11:37:00 Well, when I was Auckland Tech for a firm hiring out jukeboxes.... never had the neighbours complain. Mind you, I never actually took a jukebox half way up a ladder on the boundary.... Heather P (163)
68404 2002-08-05 12:51:00 Ground noise
0 to 40dB ok
40 to 65 marginal
65 + noisy
resol (1356)
68405 2002-08-05 13:12:00 58 dB is ok if you have a "good" modem , a good modem will ignore noise, are you having internet problems. resol (1356)
68406 2002-08-06 03:53:00 ?:| All wrong. :-(

What Telecom mean is "dBm". They didn't come to your place with a sound level meter. They put a meter on your telephone line. dBm dB relative to 1 mW in 600 ohm. It will be actually -58 dB. (because you certainly haven't got 770kV rms on your telephone line).

1mW in 600 ohms is 0.77 Vrms. -58dBm is (close enough to) -60dBm. That is, one millionth of 0.77 V rms of "noise" on your telephone line. The maximum power allowed from your modem is -6dBm (or -10? --- it's a while since I've looked at the figures). That's about 0.33 Vrms.

You have a pretty good signal/noise ratio. ;-)
Graham L (2)
68407 2002-08-06 04:28:00 Thanks Graham and all the rest. Sam H (525)
68408 2002-08-06 05:24:00 OMG Graham! :O

Did you sit there and quote all that from the top of your head, as usual??!
Susan B (19)
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