Tech Folks - Please Step In

[RB]

got any pics of that?

[Key2871]

OK, it's a V119 RT not a 36. But is brand new with instructions and I'll give you a 4' cable, 25 pair for connections. I had it in a heat sealed bag so that's why some pictures are cloudy.

[Key2871]

Being 19 stations, that's still a lot of phones. And I think it would be a nice alternative to a more expensive EKSU. It will mount back flat too, the edge flange is for mounting to their bracket. And it's more of 6" wide and 8" tall and 1.5" thick. Small foot print.
Not 100% sure if your power unit will have the umph to drive the board, and that unit though. You could get a power unit with ring voltage and that would have the amperage and voltage to drive everything. Does your key panel have a external ring key. If the CO was providing ring voltage?

[ramegoom]

Attached the tone generator to the line input of the phone. When you pick up, the dial tone sounds perfectly natural. So running it into the phone works normally. Dialing the phone blanks the tone sound, and it resumes when the dial is at rest. Also, you can't hear your own voice, since the tone voltage is only about 1 volt.

Next, I will try and place the tone generator in an input on the switchboard and see what happens. My first concern is the ring generation to the line; the AC signal might have an adverse effect on the electronic circuit. My first thought is to put a varistor in parallel with the tone signal, which would absorb unusual voltage at the circuit.

If nothing else, the tone generator can be put inside a "demo" phone, and you would get a dial tone when you lift the receiver off the hook.

[Key2871]

The reason the tone goes away when dialing is the shunt on the dial, it blocks the clicks you'd hear. And if you listen carefully with the dial turned a little you would still hear the tone.
And you are correct, in time the AC voltage will kill off your generator for the dial tone. It needs to be isolated from other voltages to protect it. I had a tone generator that also had a POTS function, I was trying to trace a live line, and because the customer didn't want me to kill the line. Some one called, and the ring voltage killed my unit. I told the customer I can't do it connected to the network, because it already killed my toner. Well the toner still worked, but the POTS function did not. So relay and off hook sense relay to operate the dial tone generator is what you need to do. Maybe you could incorporate that in the relays in the switch board. It must sense when a station goes off hook, have a relay trigger your DT generator, and when it's not needed it's just sitting there happy and protected.