HI Rod, If you are interested, I found a few more variations of circuit designs for the same idea. Another timer chip Version - http://www.vk2bv.org/w_ctcss.htm http://www.vk2bv.org/p_fig2a.gif OpAmp Version - http://www.fenlandrepeater.org.uk/ctcss.htm MX315 Version - http://www.com-spec.com/selectone/manual/st_133b.pdf 12C508 Version - http://members.optushome.com.au/vk3biz/ctcss-tones.html 16F84A Version - http://users.picknowl.com.au/~wavetel/pic.htm Cheers PK, VK4FAQ. ----- Original Message ----- From: VK4UTE To: seqpg@xxxxxxxxxxxxx Sent: Tuesday, January 27, 2009 2:38 PM Subject: [seqpg] CTCSS circuit Thanks Simon From not being to locate any easy design, to finding three.... Rod VK4UTE ----- Original Message ----- From: "Simon Chantrill" <vk4tsc@xxxxxxxxxxxxxxx> To: <seqpg@xxxxxxxxxxxxx> Sent: Monday, January 26, 2009 12:06 PM Subject: [seqpg] CTCSS circuit (link from SCARCNEWS) > Hi all, > I hope this is going to work, being my first post. > > http://www.qsl.net/sv1bsx/Subtone/Subtone.html > > Regards, > Simon vk4tsc > >