[amsat-bb] Re: Fwd: 910/1.2ghz/sequencer

Allan Saul allan at rfdesign.co.za
Sat Jan 23 21:58:51 PST 2010

Hi Bob,

You have to modify the IC-910 for it to work properly with a sequencer.
I mounted a 3.5mm stereo socket on the back of the rig at the 
bottom RH corner at the back (looking at the back). 
I cut the PTT track coming from the MIC connector going to PIN 6 on
the MIC PCB inside the IC-910 at the front. I then wired the "Tip" pin of the 
3.5mm socket to the MIC, and the "Ring" of the 3.5mm socket to pin 6. 
Ground was connected to the shield of the 2 core cable.

This way you "intercept" the PTT from the MIC and send it out the back
of the rig via the "Tip" to the Sequencer, and then the TX delayed signal 
comes back in via the Ring to fire up the Transmitter. When not running the sequencer I just put in a 3.5mm stereo plug into the socket into the back of the rig with the tip and ring bridged. 

Some words of caution. NEVER hit the "Transmit" button on the rig.
Also, if you plan to hook the 910 up to a TNC,
you MUST use the PTT line from the TNC going to PIN 3 of the ACC or
Main Data sockets otherwise the rig gets confused about what audio
source to use. What I do is send the PTT signal from the TNC to the
sequencer first, then the delayed output back to pin 3. 

Hope that helps.

Allan ZS1LS

-----Original Message-----
From: Bob- W7LRD [mailto:w7lrd at comcast.net] 
Sent: 23 January 2010 04:49 AM
To: amsat-bb at amsat.org
Subject: [amsat-bb] Fwd: 910/1.2ghz/sequencer

not takers on my first inquiry.  I even sent a note to Icom, they may get back to me someday.  I know there are some 910 smarties out there. 


I am trying to set up my 910/sequencer/amp.  Checking things out before hard wiring everything I discovered when grounding pin 3 of the acc socket the radio does go to xmit, and will do cw,  however to send ssb the ptt on the mic has to be pushed.  At times I use a Heil head set that has no PTT and I simply push the xmit on the radio.  Do I have to pick off the PTT at the mic connector?  I am probably overlooking something obvious.  What do you 910 experts have to say. 

As always, thankyou 

73 Bob W7LRD 

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