I need some help from anyone on this site. The problem is I am building a scan lock module that will stop a receiver from scaning once it hears a 2400khz tone. The tone part of the circuit works just fine but when I send the output from the LM567 (Tone Decoder) to the Trigger on the LM556 (duel Timer) the timer is supose to start by sending a signal to pin5 of the LM556 for 18 minutes but it will not do what I am asking it to do. In fact I get n signal on Pin 5. This link has the schmatics of the project. http://www.pollenpurge.com/R139_const_1_.htm
I would be etrenally greatful for some info.
Thanks
Steven R

 

First is your voltage regulation propper? Is your line clean?
Have you tried triggering it with a lower freq?.