Audichron STM Vol. 13, No 3 July[removed]D. Alderdice photo

Source URL: www.telephonecollectors.org

• Dial tone
• Telephone number
• Rotary dial
• Telephone
• Audichron
• Pulse dialing
• Phreaking
• Business telephone system
• Telephone switchboard
• Telephony
• Telephone exchanges
• Panel switch