Can I hook an extension directly to pins 9 and 10 and get emergency siren? or is a relay needed?

Ty in advance

Those are doorphone and doorphone relay for a lock.

Siren activates when?

pins 9 and 10 on the viking ctg-1 sound alarm when shorted

used to activate when ext 335 was called

The CTG-1 install doc lists the following: Pin 12 Common. Pin 11 Yelp. Pin 10 Whoop. Pin 9 Ding Dong. Shorting pin 12 to any of those other pins will produce the associated sound.

To answer your question, which is a bit confusing, if you want the CTG-1 to make a sound when the phone is being called, you must use an Industry Standard single line port and a Viking LDB-2 or LDB-3 bridged on the extension's tip and ring and the normally open contact connected to pins 12 and either one of 11, 10 or 9.

Rcaman

Thanks guys. The Ctg-1 I'm working with only has 10 pins. 9&10 shorted equals emergency tone. this is a new customer that claims this worked at one time and no other equipment was there. 335 is an analog port but didn't want to put ring voltage to pins 9&10.

Also to be noted I am new to the NEC system. Wasn't positve about the relay output.

TY

https://www.vikingelectronics.com/products/pdf/ctg-1%20(Sep%2000).pdf

Do not terminate an s/l ext to pins 9-10. In the phone programming there should be an option to apply a N/O:N/C condition, triggered when ext 335 is dialed. You'll need to find the N/O:N/C pair from the system to terminate on the CTG1 pins 9-10.