Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old August 21st 04, 05:47 PM
Fred McKenzie
 
Posts: n/a
Default

I saw a web page detailing how to connect a DTMF box to the rear of
the radio via a radio shack DTMF generator. That generator does not
seem to be available now. Has anyone built a box from something
else. I was even thinking about an old phone..

Keith-

The touchtone pad in an old telephone has numerous wires connecting into the
guts of the phone. Perhaps an old ARRL handbook or FM & Repeaters Handbook
would have information about how to hook one up, but there may be a simpler
way.

Just connect the two leads out of the phone through a series resistor (maybe
620 Ohms?), to a DC power source. The phone company used 48 volt batteries,
but it will probably work with as little as a 9 volt transistor battery.

Connect a series capacitor from the junction of the resistor and the phone, to
a potentiometer, and the output of the potentiometer to your audio input.

When the phone is on-hook, the phone line is disconnected, so you might want to
bypass the hook switch. When off-hook, the phone's earphone and microphone are
connected, so you may want to disconnect them.

Good luck!

73, Fred, K4DII

Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Icom 756, Icom 275, Icom SM-8 (Reduced) Donnie Equipment 0 July 21st 04 02:28 AM
Icom 756, Icom 275, Icom SM-8 (Reduced) Donnie Equipment 0 July 21st 04 02:28 AM
Icom 756, Icom 275, Icom SM-8 (Reduced) Donnie Equipment 0 July 15th 04 10:30 PM
Icom 756, Icom 275, Icom SM-8 (Reduced) Donnie Equipment 0 July 15th 04 10:30 PM
Icom 756, Icom 275, Icom SM-8 Donnie Equipment 0 July 8th 04 11:30 PM


All times are GMT +1. The time now is 01:18 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017