Use a Rotary Phone with a Pulse to Tone Converter

[mike121847]

There are a couple of other threads discussing this but I felt it more appropriate to start a new one. This thread is specifically about a "Pulse to Tone Converter" purchased from alldav.com.

To start, the converter works perfectly. It doesn't support * and # like some units, but at $20 shipped it's more than half the price. It also comes with a polarity reverser which, at least in my case, was needed for setup.

When the package arrived it was very neat and included everything that I needed. Setup was very easy, as the detailed yet brief instructions made sure of. Here is a picture of the unit from their website. Keep in mind that the converter I received is newer than the image provided there. My unit says "©2013 alldav.com P2Tv2.3-168 sw20120419".

I should note that their website was down at the time I was looking for the converter, but I was able to reach the company directly via email (MM-DD-YYYY@allenwan.com). Make sure to replace MM, DD, and YYYY with the appropriate two digit number. This is for SPAM purposes. Upon emailing, I received a PayPal Invoice in my email account a day or two later.

All in all, I'm very happy with the service and unit provided by alldav.com and Allen Wan. It has worked flawlessly and for the price you can't beat it. Enjoy!

[rpiotro]

I am just curious as to why you are using a rotary dial phone? A fashion statement? The old ones are built tough.

[oomamaniacal]

Mike,

Thank you for the information.

My main concern when looking for a PTT converter was finding one that could reproduce the * and # tones (using "dial hold") in addition to the numbers.

I tried a "Dialgizmo" from Australia that is supposed to reproduce the symbol tones and provide speed dialing, but it only generated the number tones. It worked the same when connected to the Telo or a Linx.

I then purchased a Rotatone from a Canadian company, and installed it, internally, into a Western Electric Princess. It works when connected to the Telo. And it can speed dial and produce the symbol tones. However, it would not work at all with a Linx.

I discovered that the issue is the line voltage. The Telo phone port produces more line voltage than the Linx. And my rotary phones use carbon transmitters. If I replace the carbon transmitter with a modern, electronic version that consumes less voltage, the Rotatone will work with the Linx. However, that is not a solution because it causes sound distortion during conversation since the phones are not designed to work with modern transmitters.

I hope this information is helpful to collectors who use Ooma's phone service.

[mike121847]

I am just curious as to why you are using a rotary dial phone? A fashion statement? The old ones are built tough.

It's just what we have hanging in the kitchen. That and it's hilarious to see people who don't know how to use it.

[oomamaniacal]

...it's hilarious to see people who don't know how to use it.

Agree: http://youtu.be/XkuirEweZvM

[suncoaster]

Heck, I remember when phones had no dial. You picked up the receiver and in a few seconds an operator would come on and say, "number please". Someone should create a phone like that with voice reconition that would dial a number when spoken.

[highq]

Heck, I remember when phones had no dial. You picked up the receiver and in a few seconds an operator would come on and say, "number please". Someone should create a phone like that with voice reconition that would dial a number when spoken.

It's been done. My smartphone can obey such a spoken instruction.

[Mister Mike]

I had a hard time confirming online which adapter worked with the Ooma Telo (aside from the Alldav.com unit, which seems to no longer be available).

In the end I rolled the dice on the Dialgizmo, and it works great! Even the *, #, and advanced functions like redial and memory seem to work. I didn't think I'd use any of these functions, but I have to say redial is handy on a rotary phone! No additional line noise or anything, either. I just plugged it in and can forget about it.

For the record, I have a Western Electric 354 wall phone (the same guts as a 302), so I can only speak for the 300 Series phones. My Ooma Telo was wired to the whole house, so I just plugged the Dialgizmo in between the Ooma and the house wiring. This to me is preferable to the Rotatone, as I don't need to get additional units if I want to get another rotary phone in the future.

[65Tiger]

I have an older X10 alarm system that only has pulse dialing and was incompatible when we switched to OOMA. The system had worked perfectly for many years and I invested in a lifetime buy of spare parts when they discontinued. I tried the new cell based (X10) system and it was total junk, no range, intermittent cell, no call out, very hard to use.
I installed the DialGizmo and at least the alarm can get one call out, but no voice recording.
The problem seems to be line voltage, which should be 40-48 volts. When the alarm tries to call out, it sags to about 7 volts and the dialing system stops. I'm not even sure why it gets one call out. But at least I know my alarm called and I can take action if needed. With the legacy ATT line, the voltage only went down a few volts. The Telo does not seem to provide enough current to hold the line up. I was excited when the Lynx came out and "works with any telephony equipment" but from what I've seen in this forum, it supports even less current than the Telo, so I haven't tried it.
I'd like to try a second power supply to hold up the line voltage, isolated to the alarm system, but fear damaging the Telo which is something that I don't want to do obviously.
I would love to keep my legacy alarm system, worked perfectly and I invested hundreds of hours in it. I don't know enough to tell how it's dialing system works and it's current requirement (could measure) and how to isolate it from the OOMA and still get the call out. It's supposed to call multiple numbers but dies when the voltage sags.
Any suggestions?
thanks,
Curtis First Time Poster

[ChrisRR]

I am an avid collector and user of antique and vintage telephones. I have tried a vast array of converters and devices to be able to use my beloved rotary phones with my ooma. There are two problems, one of which has been touched upon. The one problem is line voltage. The on-hook (phones hung up and otherwise open circuit) voltage of a phone line should be -48 volts DC. Yes, that's negative 48 volts. Phone lines were made essentially positive ground as a method of preventing corrosion in outdoor telephone lines. The tip side (green wire or white/blue wire) should be 0 volts and the Ring side (red wire or blue/white wire) is -48VDC. The other factor is loop current. You are observing low loop current when the voltage sags to only a few volts after going off hook. If you were to stick a milliammeter in series with the phone and source (ooma, local telco, etc.) it SHOULD read around 28ma. 28 is optimal, but rarely achieved. Below 25ma things start to go wrong and line powered devices (converters, autodialers, old Western Electric touch tone dials, etc) don't work properly. Above 35ma, things can also go wrong. Too much current can burn up sensitive electronics in fax machines, modems, phone system line ports and things like that. I have two ooma telo's and both are consistent around 20ma. They are pretty low. I also still have a traditional copper line from our local telco (Fairpoint- Soon to be Consolidated Communications) and it hovers around 33ma. It's because of my collection that I have so many phone lines. I like the copper because my rotary phones work without gizmos on it. I also have an Avaya Partner ACS phone system. The neat thing about the Avaya system is it has a built in pulse to tone coverter and any station port can be used for a traditional analog telephone, system phones are not required other than to program it. The station ports put out line voltages and current similar to a traditional copper phone line, so my old phones are happy to work when plugged into it. The other thing I notice is ringing voltage is much lower than traditional copper. This seems to be true of every voip device I've tried. Copper line ringing is around 100 volts at 20 hertz, most voip tops out at 80 (the ones you can adjust) and average around 40-50. The old mechanical ringers in vintage telephones sometimes won't ring or will have a very weak pathetic sounding ring. Inside the phone you can adjust the bias spring to the low-bias position and the phone should ring loud and clear. I love old phones and the art of telephony very much, and if I can be a help to anyone, don't hesitate to ask. (I also have an asterisk system and -hold on to your socks- a 1A2 system installed and working with my telo's.