
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
What is the maximum loop length for a analog port on the TA-900
I have a customer that needs to support a analog phone that is 2500 feet from the siring closet.


- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Accept as Solution
- Report Inappropriate Content
Re: What is the maximum loop length for a analog port on the TA-900
That's about an 80 ohm loop for 22-gauge and 125 ohms for 24-gauge wire. This should not be an issue at all.
If the wiring goes outside or underground you should consider adding a grounded gas-tube type protector near the TA900 for safety and to avoid potential damage from induced voltage spikes.
P.S. Beware of the stallion in that closet. He tends to kick.

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Accept as Solution
- Report Inappropriate Content
Re: What is the maximum loop length for a analog port on the TA-900
Dug this tidbit up in my notes from way back....
In most cases the Adtran is within a few feet of the key system, fax, or phone. This means very low resistance in the wiring. Low battery is fine, plenty of loop current over a short loop. In some cases the box may be on a ranch or farm with a long run of wire to a barn half a mile away. Higher battery is needed to ensure enough current flow to reliably signal off-hook and power the phone at the end of the line. Auto-battery senses the actual loop current off-hook and adjusts voltage accordingly.
Hope it helps!