Batboard

I have my external ICS Linker II-a controller interfaced to my Desktrac. Problem is the internal desktrac controller is over-riding my external controller. In other words when i disable the transmitter with my external controller the internal desktrac controller keeps the transmitter on. My external controller is not keying the transmitter but the internal desktrac control board is. I have scratched my head for 2 days now on this and cant figure out what i am over looking. Has anyone on here had this problem and if so what did you do to fix it? Thanks ahead of time!

Shane KI4M

What do you mean by the internal "Desktrac" is over-riding
the external ICS controller? Last I knew the Desktrac only
had either a DC remote input, a remote tone control or local
PTT for control.

I think you need to explain a little more detail on what
you have and what you think is wrong.

Has the site taken any lightning strikes that may have
caused a problem?

Is there another radio device invo9lved that you havent
told us about?

How is this all connected?

What are you doing to unkey the radio that you say
stays keyed when the external controler is not keyed?

How do you know the external controller is not keyed?

Jim

KI4M wrote:I have my external ICS Linker II-a controller interfaced to my Desktrac. Problem is the internal desktrac controller is over-riding my external controller. In other words when i disable the transmitter with my external controller the internal desktrac controller keeps the transmitter on. My external controller is not keying the transmitter but the internal desktrac control board is. I have scratched my head for 2 days now on this and cant figure out what i am over looking. Has anyone on here had this problem and if so what did you do to fix it? Thanks ahead of time!

Shane KI4M

The repeater is sitting on the test bench so no it hasn't taken any lightning strikes hihi!

No other devices installed. The external controller is wired up as such...
Controller PTT out is wired to pin 13 on back of repeater connector Accy #2
Controller Audio out is wired to pin 22 on rear of repeater Accy #2
Controller Audio in is wired to pin 23 on rear of repeater Accy #2
Controller COS in is wired to pin 9 on rear of repeater Accy #2
Controller CTCSS in is wired to pin 12 on rear of repeater Accy #2

I think that is the proper way to do that from what I have read on here at the following link:

http://batboard.batlabs.com/viewtopic.p ... t=desktrac

As far as what is happening is this.

#1 DTMF command is sent over the air to turn off TX. This is decoded by the external controller. It then sends a confirmation beep then immediately turns off the PTT output.

#2 I check to see that the PTT does drop out by visually looking at the on board LED in the controller and measuring the PTT output with a meter. PTT is def. off at this time.

#3 COS light is on when a valid signal is present on the RX frequency. Check voltages and indeed COS is present as it should be when keyed with my HT.

#4 I unkey the HT and the repeater drops out. I then verify that the external controller PTT is off. It is. I then re-key my HT to check to make sure the repeater TX is indeed turned off. Immediately on the external controller COS is present. I then unkey the HT and hear the repeater unkey. This is verified with another receiver that indeed the repeater is retransmitting the audio etc from HT#1 to HT#2 via the repeater. This is all happening when the external controller has obviously turned the TX off. During all of this testing the PTT LED on the external controller does not light nor does the state change verified by a meter. The repeater is setup for ptt to be active high. So I know that the controller being at ground has nothing to do with that..

Maybe I have a programming issue I am not sure. I have looked at my programming and can't locate any obvious issues. I hope all the above makes sense. If it doesn't let me know. I am not the best at words sometimes..

Shane,
Is it neccessary that you have two controllers? You can always just tie into the 16 pin accessory on the back of the radio with the controller.
Doug

I basically want my external controller to handle all of the control functions. I want it to handle ptt etc. I think this can be done but I have to figure out what is going on b4 I can move on.. I guess I need to scrounge around for a service manual to see how this desktrac is wired internally..

If you push the front panel "Repeater/Base" button, the "Base" LED should light and that should disable the internal repeat function.

xmo wrote:If you push the front panel "Repeater/Base" button, the "Base" LED should light and that should disable the internal repeat function.

That will disable both the internal repeater PTT and the EXT PTT.

Grounding pin 20 on the ACCY 2 connector will disable the internal repeater PTT.