I have an SL2100 installed with a single Valcom 1030C page horn powered by a Valcom 324 power supply. Cat5 cable (125 ft.) with blu/wht (Tip) org/wht (Ring) grn/wht (-24V) brn/wht (GND). Using pins 1 and 8 to get the paging. When the customer uses external page, the audio breaks up and is intelligible. I played with the gain and added a V1094A because Valcom said the audio was too low coming from the NEC, but it still does the same thing. I have installed these before with this method on the DSX and SL1100 without issue. Softly speaking seems to be OK, but any type of normal speech breaks up. I also made some change that took effect when I disconnected from PC Pro that now gives a low beeping over the page horn ALL the time. Thoughts?

24V on a page port? Sounds to me like that paging system is setup to page via a trunk port.

The Valcom 1030C is a self amplified horn that uses 600 Ohm T/R input and a separate -24VDC power supply. It eliminates the need for a traditional 25V or 70V Amp and horns.

Ah, I thought you had 24V on the T/R to the phone system. Have you tried moving the horn by the system? Is this a new cable? Could the power be bleeding into the talk pair?

Turns out I just needed a larger 24V power Supply because the run was longer than usual. Good and strong paging now.