something I found online that I had as a child. This book and its projects kept me busy for a very long time
http://chiclassiccomp.org/docs/content/books/TelephoneAccessoriesYouCanBuild_JulesHGilder.pdf -- Dead Link
Updated link to Amazon.
https://www.amazon.com/Telephone-Accessories-You-Can-Build/dp/0810457482 (https://www.amazon.com/Telephone-Accessories-You-Can-Build/dp/0810457482)
and The Internet Archive
https://archive.org/details/telephoneaccesso00jule/page/n7 (https://archive.org/details/telephoneaccesso00jule/page/n7)
There was also More telephone accesories you can build.
https://www.amazon.com/More-telephone-accessories-you-build/dp/0810408937
:) with all the old information on old #55 units, etc. as long as the component values are given anything can be rebuilt! (that is if you know how to make your own PC Boards!)
Nice. Looks like another great old find.Link to "More telephone accessories you can build" on Archive.org-https://archive.org/search.php?query=more telephone accessories you can build (https://archive.org/search.php?query=more%20telephone%20accessories%20you%20can%20build)
Great thread.
D/P
I had the green book also! :)
The call timer circuit is interesting as in the UK a lot of people have inclusive call packages, but if your call exceeds an hour the whole call is charged per minute.
Good phone porn!
I had this downloaded but can not find it now. Anyone have it PM me please
Ok it just got moved on that site here is the new link
http://vtda.org/books/Telephony/TelephoneAccessoriesYouCanBuild_JulesHGilder.pdf