UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Telephony and Telecomms

Notices

Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment

Reply
 
Thread Tools
Old 18th Oct 2017, 6:37 am   #1
Dave Moll
Dekatron
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 3,321
Default Another novelty telephone - this time a frog

I recently acquired the telephone pictured below in a non-working condition. After replacing a faulty line cord and open-circuit receiver inset (originally a 2" 100Ω paper-cone speaker), everything works except for responding to a ring signal.

As can be seen from a youtube clip I found, the LED eyes should flash and it should make a chirping sound from a piezzo-buzzer. Neither of these happen, though the eyes do light up when a loop is made. I suspect, therefore, that whatever generates the current to operate the LEDs and piezzo-buzzer isn't working. This time the circuit contains a single IC labelled "YC 2080", but I can't find any data for it.
Attached Thumbnails
Click image for larger version

Name:	frog telephone.jpg
Views:	43
Size:	32.2 KB
ID:	150939  
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)
Dave Moll is online now   Reply With Quote
Old 18th Oct 2017, 7:43 pm   #2
OscarFoxtrot
Hexode
 
OscarFoxtrot's Avatar
 
Join Date: Apr 2011
Location: Edinburgh, UK.
Posts: 477
Default Re: Another novelty telephone - this time a frog

It could be as simple as needing a ringing capacitor in the right place. Is the phone 2-wire or 3-wire and do you have a ringing/bell wire at the socket you're using.

Try plugging into a microfilter if you're not sure you have a bell wire at the socket you're using as that will recreate a ringing wire.
OscarFoxtrot is offline   Reply With Quote
Old 18th Oct 2017, 7:55 pm   #3
Dave Moll
Dekatron
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 3,321
Default Re: Another novelty telephone - this time a frog

The socket used is a master socket (connected to an extension of my house PABX), but the 'phone is most definitely two-wire anyway. The original cord only had two cores emerging at the 'phone end.

I will try to track down a ringing capacitor within the 'phone and check that it isn't o/c.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)
Dave Moll is online now   Reply With Quote
Old 19th Oct 2017, 8:27 am   #4
Dave Moll
Dekatron
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 3,321
Default Re: Another novelty telephone - this time a frog

Finding the cap. wasn't a problem. It was obviously the "big yellow thing" with one end connected to the "B2 leg of the line. As I got no reaction out of connecting ohmmeter across it, I substituted one which does give the expected flick of the meter needle. Unfortunately the problem isn't going to prove that simple - still no chirp or flashing eyes.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)
Dave Moll is online now   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 10:09 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright ©2002 - 2018, Paul Stenning.