|
Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment |
|
Thread Tools |
18th Dec 2018, 1:10 pm | #1 |
Diode
Join Date: Dec 2018
Location: Dublin, Republic of Ireland.
Posts: 4
|
Western Electric 500 - Rotatone v1 Install
Hi all,
First time caller, long time listener. I've had a Rotatone v1 sitting in a drawer for years and finally decided that while I have some time off during this year's Christmas period that I'd install it into my Western Electric 500. I've run into a few issues though and I'm wondering if somebody here can be of some assistance. I have a zener diode in the kit and I know that I have to install it between RR and F but I'm not sure which direction I'm supposed to install it in. Not sure which is supposed to be anode and which is supposed to be cathode. I'm not educated enough on schematics so I can't read the diagrams in a way that makes this obvious to me. I've tried it in both directions though and I've... kinda gotten the Rotatone working. I've connected all of the contact points in the correct places and sometimes the Rotatone will output a proper DTMF tone and sometimes it'll just introduce random noise into the line. Anybody know this may me or what I may have done wrong? It's driving me up the wall as I really want this to work. |
18th Dec 2018, 3:11 pm | #2 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,130
|
Re: Western Electric 500 - Rotatone v1 Install
I don't suppose you have a circuit/wiring diagram of your telephone available, do you? That should provide a starting point for working out how to wire in the Rotatone.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley) |
18th Dec 2018, 3:46 pm | #3 |
Diode
Join Date: Dec 2018
Location: Dublin, Republic of Ireland.
Posts: 4
|
Re: Western Electric 500 - Rotatone v1 Install
The wiring diagram is available here:
I've rewired it to work on my phone system correctly though. https://www.telephonecollectors.info...g-diagram/file The black wire from the telephone chord (US standard) is wired to L2 to ring the bell correctly for instance. I have connected the Rotatone to the phone correctly according to the instructions so I'm not worried about that... It's just... the Rotatone that seems to be acting up. I've stripped back wires and soldered them together to make sure that everything is connected together correctly and like I say sometimes the Rotatone will function as expected... but then at other times it will just introduce odd noise onto the line... like as if it's not playing back the DTMF tone correctly. Or it plays back in a way where it sounds very far and distant. |
19th Dec 2018, 5:14 am | #4 |
Pentode
Join Date: Jan 2013
Location: Powell River, British Columbia, Canada.
Posts: 217
|
Re: Western Electric 500 - Rotatone v1 Install
I am not familiar with your DTMF device.
However, WE 500 telephones have been part of my past. A phone such as that will work on a line without respect to the polarity of the incoming two wires, as long as the ringer is connected across the line, and is matched to a capacitor tuned to the proper frequency. Ringer aside, the phone line has a polarity. The 500 set will work either way. You mentioned a zener diode. The anode and cathode must be connected such that the rated voltage will appear across it. If the connection is reversed, the voltage will drop to a nominal value, usually 0.6 volt. For experimenting with the hookups, a multimeter in series with your phone will show two things. The nominal line current from the telco switch, and the polarity of the current. It should be constant for any phone you are using. If your zener diode is hooked up such that the DTMF works, the 500 set should behave as any other phone. However it it works sometimes, and not others, the line current and/or the polarity may have changed downstream from your telephone connection point. Good hunting.. We who collect and concern ourselves with old phones sometimes use the instrument shown. It is a Radio Shack telephone analyzer. (Cant be helped. Father was a telephone man)
__________________
Steve Dow VE7ASO |
19th Dec 2018, 10:17 am | #5 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,130
|
Re: Western Electric 500 - Rotatone v1 Install
The Rotatone kit includes a bridge rectifier to ensure that its electronics, including the zener, receive the correct polarity regardless of the polarity of the incoming line voltage.
Two other thought have occurred to me regarding a Rotatone that sometimes works (which it will presumably only do with the zener correct) and sometimes doesn't. The first is that the Rotatone, running on much lower currents than are normally passing through the contacts of a dial, is very sensitive to any oxidation or other contamination on the dial contacts. I found with mine that I had several goes at cleaning the contacts before achieving reliable results. The other, given the reports of DTMF tones sometimes being replaced by random noises, is whether the line voltage is on the low side, so that the Rotatone is not always receiving sufficient juice to work properly.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley) |
19th Dec 2018, 1:55 pm | #6 |
Diode
Join Date: Dec 2018
Location: Dublin, Republic of Ireland.
Posts: 4
|
Re: Western Electric 500 - Rotatone v1 Install
I suppose it couldn't hurt to try the bridge rectifier.
I figured that considering I'm connecting it up to a Virgin Media Superhub which has (what I assume is) VOIP functionality that I wouldn't need to worry about the polarity. I'll give it a go though to see if it helps. Ohh also, I know that I'm supposed to connect the zener diode across RR and F terminals on the network... but does anybody know in which direction it's supposed to go? |
19th Dec 2018, 11:40 pm | #7 | |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,724
|
Re: Western Electric 500 - Rotatone v1 Install
Quote:
The polarity issue of the Rototone still applies.
__________________
-- Graham. G3ZVT |
|