NOISY CONNECTIONS?
          (Minimum Line Testing Requirements as set by the FCC.)
                           ...by Lloyd Kautz
     From "The CPC Newsletter" A monthly publication of the Connecticut
     IMB Personal Computer Users Group.

                                   *

     Your local telephone company is required by the FCC to provide a
minimum level of quality on the lines it maintains for your use.

    Many lines do not meet these standards, and so are a source of 
considerable noise in transfer of data between computers. A noisy line can 
make it very difficult to upload messages and files to a BBS.

     If a SYSOP complains to the telephone company about line noise, there is 
usually only one option offered: line conditioning. This is an extra cost item 
that they would like to sell you. However, if their line to your computer
meets the minimum standards, there is no reason you cannot have error-free 
transfers at 2400 bps and, if an error-correcting protocol is used, reliable 
operation at 9600 bps is the norm.

     If the telephone company seems reluctant to test your line and assure 
that it meets the minimum requirements (and they will), request that they run 
the following tests and provide you with the results. Let them understand
that if they do not comply, you will refer the matter to the FCC. They will
not be happy.

     The following tests should be run:

     1. Frequency sweep; 300 to 3000 hertz.
     2. Roll off 5 to 2500 hz with -2 to +8 range. 300 to 3000 hz: -3 to +12
        range. 1000 hz tone loss  -16, 1% either direction.
     3. Signal to noise: 24db.
     4. White noise C, message Dbrnco.
     5. Envelope delay measurement.
     6. Phase jitter, not to exceed 10%.
     7. Impulse noise test. Min. 15 minute test.

     Don't worry if you do not understand what all these tests mean, the 
telephone company knows. There standards are all available from the FCC upon 
request. When the lines provided to you meet these minimums, you will 
experience reliable, accurate, and noise free data.

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Another text file from Stonehenge BBS [415] 479-8328
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