dsk - I already suggested this.

Already googled ONIX TELMAR. I see photos of phones but no circuit or wiring diagrams.

I would still like to know what are S3 and T used for. Seems strange that they would provide terminals like all dressed for a party with no place to go.

 

Hi!
Buzzed out the switch again. I've given some bum information. Heres what buzzed out.

x-z and u-w = shorted when OFF hook (as in switch 'open' / leaver up)
x-y and u-v = shorted when ON hook (as in switch 'closed' / leaver down)

y-z and u-w = always open.

No trace between s3 and t. In fact there is nothing going from 't' that I can see. Which I thought was odd as there is definatly a screw point. I thought it was for tieing two wires together? Same for S3 - nothing from that either.

I got the same results from google. Pictures of phones, but nothing with regards to the circuit. Italian though...

 

Just a thought. Could the fact I'm not testing with the dialer attached be hampering efforts? Just wondering if that ties anything together whilst its off hook and not dialing. Just thought I'd ask. Hopefully thats not a stupid thing of me not to mention before hand!

 

I guess this is the diagram:
Basically the same as used in Siemens telephones since 1927 improved by better and smaller components. The resistor, and capacitor near the transformer makes a considerably better line balance.
The carbon transmitter (I guess) could probably be replaced by an unit with a modern microphone, and some electronics. Then the sound should be like modern telephone.

dsk

 

Hi!
Buzzed out the switch again. I've given some bum information. Heres what buzzed out.

x-z and u-w = shorted when OFF hook (as in switch 'open' / leaver up)
x-y and u-v = shorted when ON hook (as in switch 'closed' / leaver down)

y-z and u-w = always open.

That is what I suspected.

Hence this should work:

RED to a
GREEN to b

 

HAHA! Success! I hooked up the dial and bingo bango we have a dial tone! Wow. I wish I tried that before waisting you guys time on it. I didnt think that the dialer would be part of the circuit enough to make a different until I started thinking that something on it could be bridging something else.

Thanks a lot you guys! At least I now have some idea on what to look for with regards to how a simple circuit works. Its always refreshing to learn something new!

Thanks so much again!

 

Do you guys mind if I raise a new thread about what electronics you need to change from the carbon mic to a modern electret (is that the correct term?) mic? Or is it ok to be answered here? Im thinking about how to help out other people.

Thanks again guys! I would of been lost with you!

 

It's ok to continue in the same thread since (a) it is on the same topic and (b) you've solved the original problem.

No. It is not ok to replace a carbon mic with an electret mic. They work on completely different principles.

 

No! but you may get a replacement capsule containing a modern mic. and amplifier, just to put in.

dsk

 

Cool. Understand that I can't do it. Just wondered if there was a way to do it. Seems though according to dsk I can get a replacement capsule. Might go that route.

Thanks guys!

 

I have used a capsule from Siedle (door telephones) marked 11040, works well, but needs wires to connect.

dsk

 

I have used this from Siedle (German door telephones) marked 11040
I found one on Ebay now: http://tinyurl.com/aq5oher
This one works with all telephones I have tried, and copes with quite low voltages, the drawback is the terminals, who needs wires, not only to press in on the springs for older capsules.
dsk

 

Sorry for the delay. Thanks for the information dsk! I'll have a look at these. I can solder onto the mics as I'm building the circuit up outside the original case. Come to think of it, the original also just soldered directly onto the mic....

 

Maybe you have a good mic already?
Carbon transmitters has granulate inside, you may here its moving in there when moving/shaking it.

dsk

 

Hi.
I think I do have a good one. Although, the reason why I would like to change it is because I'm trying to fit it into a smaller case where the current one just wont fit. Therefore I would like to use a smaller mic. Unless I can get a smaller carbon mic?