There may be several types of DSL filters out there. Each may have a different frequency response characteristic.
The original ADSL (Asymmetric Digital Subscriber Network) had a frequency range starting at about 25kHz and ending at about 1.1MHz. The range from 25kHz to 138kHz is the "upstream" and from 138kHz to 1.1MHz is "downstream". The wider bandwidth for the downstream is designed for faster downloading, since most people download more than they upload. Now there are DSL types that extend to 2.2MHz (ADSL2+), 4.4MHz (ADSL2++), 12MHz (VDSL) and as high as 30MHz (VDSL2). There are also variations that may end at some other frequencies between 1.1MHz and 30MHz depending on the local service. The phone frequencies (called "POTS" - Plain Old Telephone Service) range from DC to about 3400Hz. The DC signals include the "ringing" voltage. Signals in the ranges above (voice from DC to 3.4kHz and DSL from 25kHz to up to 30MHz) may be present on the twisted-pair telephone cables from the Central Office to the home (called the "local loop"). 73, John W2XS _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
