Ramsey Electronics SP1 Manual 

1, HANDS-FREE SPEAKERPHONE- INTERCOM KIT Ramsey Electronics Model No. SP1 How many times have you played acrobat juggling the phone on your shoulder while looking up something or while working at the bench? And, wouldn’t it be nice to be able to ans…

18, SP-1 • 18 "The only practical and economical solution used to date is to design the speakerphone to function in a half-duplex mode: only one person speaks at a time while the other listens. To achieve this requires a circuit which can detect who is talking, switch on the app…

9, Ramsey Electronics SP1 SP-1 • 9  A) If you plan to use your SP1 as a telephone speakerphone, install zener diode D5 (small gray body with black band). The banded end marks the cathode and must be oriented as illustrated.  B) If you plan to use your SP1 only as a duplex intercom, do not install D5. Place…

3, SP-1 • 3 SP1 HANDS-FREE SPEAKERPHONE- INTERCOM KIT Ramsey Publication No. SP1 Price $5.00 TABLE OF CONTENTS Introduction to the SP1...................4 Parts list for the SP1 ...................... 5 Parts layout diagram ......................6 Assembly instructions.............…

17, SP-1 • 17 battery connection. If the battery improves performance, then continue using it for that particular location. It is switched in and out of the circuit by the "B" section of S1. C. Finally, you may encounter situations where the person on the other end just is not…

24, SP-1 • 24 SP1 SPEAKERPHONE-INTERCOM KIT Quick Reference Page Guide Introduction to the SP1...................4 Parts list for the SP1 ......................5 Parts layout diagram ......................6 Assembly instructions.....................7 Schematic diagram............…