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Rotatone vs Dialgizmo - Dial Hold features

Started by MCCAFFRP, October 22, 2015, 11:27:53 PM

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dsk

Thank you, it seems like you have done a great job finding better solutions than we have before you.  It is pretty frustrating with the total absence of communication with the DialGizmo makers.

So far this is my best option for reverse dial phones so I have to keep using this for my Oslo telephones.

dsk

HarrySmith

Congrats! perseverance pays off! If you don't mind , please post the summary here. That would make it useful in the future if anyone researching this topic comes upon it at a later date and don't have the email. Thanks!
Harry Smith
ATCA 4434
TCI

"There is no try,
there is only
do or do not"

MCCAFFRP

Hello all, To summarize my Dialgizmo installation on a WE 302 phone - First I had to review the original WE 302 wiring diagram and become very familiar with the stock wiring and make sure that my phone was wired correctly. That included checking the voltage across L1 and L2 to make sure that L1 was negative, regardless of the wire color. In my case, the Ooma Telo CO battery voltage is reverse polarity, so that meant the green wire was negative so I had to switch the red and green wires on the line input. Then I tested the off and on hook voltages and also when when dialing - which was zero. From posters here, and from comparing the WE354 diagram which was easier to read, I confirmed that OV when dialing wouldn't work to activate the dial-hold features, but the unit dialed numbers properly. So I moved the slate red wire connected between R on the dial and L1 to the R terminal on the coil, which wouldn't completely shunt the whole set. I then measured the voltage when dialing and now it was .5V. So then the dial-hold features worked, but not reliably, so I checked the off hook voltage and it was 2.8V. From reading the Rotatone install instructions, I read that he dealt with this same issue by using a 5.1V zener diode. This is needed apparently because the original carbon transmitter and receiver elements' impedance is low. I then inserted a 5.1V zener diode between BK on the dial- and the black wire going to the receiver with the zener cathode facing the BK terminal. That raised my off hook voltage available to the Dialgizmo to 7.7V and then the dial-hold features worked reliably with one caveat - they work by dial and hold for 3-4 seconds, not two. So after all of this, dialing a # and * work, but some digital systems won't recognize those tones due to the time it takes to dial and hold, especially if you have to dial it twice before recognition. In my case, I can access my voicemail but when it asks for me to type in my password followed by a #, the # is not recognized due to the time between dialing digits and waiting the 3-4 seconds to dial the #. But I was determined to get this working properly regardless! Someone here said it worked properly on a similar phone, so mine had to work properly! Hope this helps someone. Feel free to email me if needed. I am now on to testing a Rotatone and comparing the results.

dsk

Great if I read this right you have put in the zener diode like in my schematic's showing dial and handset of a 30x phone.
and as you mentioned the polarity is of importance for getting this right.
What this does is actually making the voltage drop over the telephone having a easy detectable difference between dialing, and dial in rest position. When this difference are so easy to detect, the dial gizmo at last understands the difference of dial in rest position (voice) and dialing.

dsk

MCCAFFRP

Hi - DSK,
The diagram does accurately show what I did to my phone - however to reinforce the reason - I installed the zener to raise the off hook voltage, not drop it. The dial shunt slate red wire when moved from L1 to R on the coil provided the voltage drop when dialing with or without the zener, but the off hook voltage - with dial at rest was only 2.8V before the addition of the zener. With the zener, it raised the voltage to 7.7V.

G-Man

This thread has become so absolutely convoluted and difficult to follow, so I have to ask the following; isn't the zener inserted exactly in the same location as shown in the schematic provided by  Old Phone Works?

dsk

Not seen that, but yes if it is this: http://www.oldphoneworks.com/files/oldphoneguy/rotatone//Rotatone%20-%20WE%20302.pdf

This diode makes obviously even the Dialgizmo work better.

dsk

tabormeister

Reviving an old thread here - think it would work with a 500 series phone? I have a number of them but having similar dial hold issues to you @MCCAFFRP

MMikeJBenN27

Actually, the 354 is the wall version of the 304.  If you try to wire them like a 302, they will not work right.

Mike

MMikeJBenN27

The 354 is actually the same as a 304.  Not exactly the same as a 302.

Mike