Dank je voor je reactie, Kees. Voor de vertaling heb ik Wikipedia aangehouden. Lighter fluid is hetzelfde als nafta en dat is weer een ander oplosmiddel. Mogelijk krijg je daar hetzelfde resultaat mee, maar dat heb ik nou eenmaal niet gebruikt.
Hi Kirsty, an electronic microphone will not work. It needs additional circuitry to make that work.
The original carbon microphone modulates the current passing through it with the sounds it pics up. An electronic microphone generates a weak current with the sounds it picks up. The current it generates is too weak for telephone circuitry.
I have a replacement microphone if you like, for 10 e excl shipping.
Please send me an email on firstname.lastname@example.org
I think Kirsty was refering to the electronic mics that do indeed have the built in driver circuitry to directly replace a carbon mic. For example the model 21A electronic mic that was a drop in replacement for the regular carbon mic in British 706 and 746 telephones. Link follows: The silver mic is the carbon version and the red one is the electronic replacement: https://antiquephones.blogspot.com/2012/07/21a-microphone-replacements.html
Internally the active device is a standard small signal electret mic insert with an integrated circuit amplifier incorporating a relatively high current ‘Darlington’ output stage. The mic is also polarity insensitive just like its carbon counterpart.
Thank you this post. I am a collector who thinking to begin to start in rotary telephone repairing and I find the most difficult part is how to remove the cover without breaking something. My next fear is I am afraid to damage something that is originally was working. Please advise.
Hi Sara, start easy and do not disassemble too much. Especially if the phone works fine. It can only get worse. 🙂
Of course it is a different story when the phone is broken and needing repair.
If you are not sure, ask around. Sometimes there is a trick.
There are several forums on line, where you can ask your questions. And of course there are several groups on facebook, like mine: https://www.facebook.com/groups/vintageandantiquetelephones/
You’re welcome to join.
Thanks for the tutorial!
I just purchased an older PTT rotary dial phone made in Holland and the line cord (green, blue, yellow and red) were connected to an old style 4 prong plug. I spliced it temporarily to a newer style 4 wire modular cord/plug. The phone did everything but ring when I called it, made and received calls and had a dial tone but wouldn’t ring. A friend told me a different way to wire it and it would ring but not make or receive calls. I have photos of the inside of the phone, the old plug with the 4 wires and the schematics for the two ways I wired it. Can you help me get this thing wired properly? Are you familiar with US phone wiring and color codes etc? Thank you
Yes I have several pictures of the inside, I will email them to you but I found an older wiring diagram for these phones that Radio Shack here in the US supplied to the customers along with these PTT phones it sold to customers. I will email those to you also. Thanks
Hello Arwin, I got my Ericsson Dialog last week in untested condition, before I test all functions I open the microphone part and close it again, the microphone has no wire but have metal plates. After that I test to receive and send call but they cannot hear my voice. I’m afraid that this could be that I put the mic in a wrong place or it is completely broken.. Do you know how to check it? I have a spare phone but it is a Japanese phone and has cable to the microphone.
Hi Danny, thanks you for your message. Please check if you correctly fasted the cap. It may be that he microphone does not sit straight and that prevents you from turning the cap back on fully. If so the contacts do not connect to the microphone.
Also you could try bending the contacts up a little.
Thank you for your fantastic website and comprehensive information.
I have an Ericson type 1951 (build 1969) phone. I can answer phone calls but not dial a number: the finger wheel is not working smoothly enough. Should I lubricate the finger wheel (from the inside)? If so, which oil should I use (brand, specifications)?
Thank you again for all your good work. Regards, Ben