* behind noname PBX

I have setup * behind a noname small PBX using a x100p, now when the phone rings it takes 10 to 30 seconds before * gets the call!!
Just experimenting I took an other direct analog line rang it and * picked it up right away.

Now a few week ago I read something about the voltage on the analog line being different on some PBX line, That article wrote that its possible to change the zaptel source and rebuild zaptel to adopt to this change in voltage.

My problem is, I cant find this article anymore. Did I read this in my dreams or are there people fermiliar with this ??

Greetings and thanks for reading my question !!

Does Asterisk show anything in the CLI when you are ringing it? Have you tested the ring voltage from the noname PBX with a multi-meter? It should be between 90v-110v

I do have logging from *

    -- Starting simple switch on 'Zap/1-1'     ## this line apear after 10 to 20 sec. of ringing. but sip phones dont ring yet
    -- Executing SetVar("Zap/1-1", "FROM_DID=s") in new stack    ##this apears after another 10 to 20 sec. and the sip phones start ringing.
    -- Executing SetVar("Zap/1-1", "FAX_RX=disabled") in new stack
the rest is like a sip-sip log

I am going to find my multimeter, and post the results later …

Thanks !!