Good evening, all! I have a question regarding the Melco and Teltone intercom units and wondering if anyone has done this or if it’s even possible.
So I have a 19-station rotary intercom, and a 19 station tone intercom. I know they made a combination R/T one to handle either setup, but has anyone ever made it work together with the rotary and the tone side by side? On the surface, it seems possible in my head, only assigning a tone number to a tone phone, rotary to rotary phone, and leaving the other one blank, as they have the same numbering scheme I believe.
Sam seemed to think it would cause an issue, but suggested I post it to see if anyone has done something similar. Thanks in advance!
Bob
Here ya' go:
https://www.telephonecollectors.inf...k-intercoms-1984-brochure-practices/fileStart at page 22/32:
KC-19™ KEY TELEPHONE UNIT
NINETEEN STATION COMBINATION INTERCOM
(FOR TONE OR ROTARY DIAL OR BOTH)
Thanks! I saw that and that looks like it would be great, but if I already have a tone intercom and a rotary intercom, can I ‘combine’ them of sorts to accomplish basically the same thing? I realize it may not be as clean or as practical, just wondering if it’s possible
You really can't combine them since you'll need to tie the tip/ring for each unit with the other. My money says that you'll end up causing both units to go and stay off-hook if you do this. Now since they are being fed from the same power supply, it might not be too dangerous to give it a quick try. I'm not a big fan of back-feeding a foreign voltage of any kind into a T/R output though.
You can certainly put two intercom buttons on the phones, one for each intercom and just tie all of the buzzer outputs together. The rotary phones will have to do their dialing on one button, or 'path' and the tone ones on the other. You just pick up on the lighted intercom path button to talk from either type of phone. You won't cause any harm by tying the buzzer outputs together since those are just derived by a matrix of dry relay contacts.
Do these units put out "dial tone"? I know my Valcom's did. If they do, the dial tone won't go away on the unit that didn't receive digits. Use a tone phone and the rotary unit will never receive the digits and keep delivering DT. Likewise the tone unit if you're using a rotary phone.
Another option is to use the tone only unit and put a pulse to tone converter on it's t&r output. The converter will ignore tones, and the DICM will ignore the pulses.
Valcom units did provide their version of dial tone, which I refer to as more of a buzz. Keep in mind that these intercom units, regardless of manufacturer, were not sophisticated at all. A simple dial-buzz action was all you got. Oh sure, there were some add-ons, especially by Valcom, that added voice announce, etc. The reality is that most units by Melco, Tone Commander, Tellabs and Teltone provided a simple talk battery path. They all stepped up their game toward the end with much higher levels of sophistication, such as WE's 6B (Dialog) or Tone Commander's ML-8000 intercoms that were almost mini PBX systems, but by that point, the divestiture occurred and products like AT&T's Merlin pushed 1A2 off the cliff.
Installation-wise, in comparison to wiring most other 1A1/1A2 intercom systems, these little packaged units were labor saving miracles. It's no wonder that all Bell companies jumped on them in favor of WE hardware.
Install the rotary unit and extend its T & R and Lamp lead to the ICM key on all the rotary sets.
Install the tone unit, and extend its T & R and Lamp lead to the ICM key on all the tone sets.
Connect the buzzer leads from the rotary unit and extend them to all the sets, both rotary and tone, according to your signalling plan.
Strap each individual signal (buzzer) lead from the rotary unit to its matching buzzer lead on the tone unit, at the MDF.
At the MDF, strap the station Lamp leads from both units together.
At the MDF, connect a 0.5 to 2.0 mFd capacitor between the Tip of both units, and a 0.5 to 2.0 mFd capacitor between the Ring of both units. Use non-polarized caps.
You can cannibalize the caps from a 400D KTU if you don't have a source.
Install the units per the practices and pay strict attention to power feed polarities!
Let us know how it works.