What is the maximum cable distance on a FXS port on a TA 908 or 924?

[Anonymous]

What is the maximum cable distance on a FXS port off of a TA 908 or 924?

[Anonymous]

I'm also interested in this answer, and unable to find much information on the matter.

[Anonymous · Accepted solution]

Hello David,

The line length depends on the gauge of wire you are using.  You cannot exceed 1200 ohms of resistance on the line and a phone usually has about 500 ohms, so you are left with 700 ohms total.  If you are using 24 AWG wire, you have about 50 ohms of impedance or resistance added per 1000ft,  if you are using 26 AWG wire, you have about 100 ohms of impedance or resistance added per 1000ft.  So without bridge taps on the line, you can go about 14,000 ft with 24 AWG wire.  This does not mean that the telephone and fax machine can match this length, but the ADTRAN is good up to pretty long distances.

I hope this helps.

Regards,

Geo

[Anonymous]

Useful info, thank you!

[Anonymous]

Thanks for the useful information.I will test a TA 924 at about 4-5,000 feet and see wow it works.