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New Contributor

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.

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Honored Contributor

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.

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New Contributor

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!