TK-690 ignition sense mod info inquiry

[NYkentk]

Hi everyone. I am new to amateur radio. I do not know much about it. I am wondering if you could help me. I have found online an ignition sense mod for TK-x30 radios

TK-730 ignition sense mod

However, I am looking to perform the same ignition mod on a TK-690. I have exhausted google and bing trying to find a similar mod. Any help is greatly appreciated.

 

[mrweather]

You'll need to find a copy of the service manual. The ignition sense mod involves moving some 0 ohm jumpers around on the control board.

 

[yankeephill]

Send me your email, I will send you the service manual. My mail phubbard@nc.rr.com

 

[snoopyII]

The proceedure is the same for all x90 series.

 

[ramal121]

What are you thinking of doing? If all you want to do is switch the radio on and off with the ignition, it will do this just fine by switching the B+ red lead. The radio remembers what state it was in when the power was removed and will resume that state when power is re-applied.

Now if you want to use other optional settings, like timed power off or horn alert defeat, a KCT-18 ignition cable will be required for those.

 

[jim202]

What are you thinking of doing? If all you want to do is switch the radio on and off with the ignition, it will do this just fine by switching the B+ red lead. The radio remembers what state it was in when the power was removed and will resume that state when power is re-applied.

Now if you want to use other optional settings, like timed power off or horn alert defeat, a KCT-18 ignition cable will be required for those.

The best way to do it is to just use the ignition cable wire that goes into the accessory connector. I believe that the jumpers in the control head come from the plant already set in the correct position. However I could be proven wrong. But all the radios I have hooked up all needed the +12 volts supplied to the control head on the ignition wire accessory pin to turn the radio on.

I would never attempt to control the radio on off by trying to switch the high current red wire. That is like asking for disaster to occur at the switch you tried to use. Plus the transmitter probably wouldn't work correctly due to the voltage drop through the switch.

 

[ramal121]

If the radio from kenwood was ordered with the ignition cable and factory assembly, the jumpers for ignition sense will be set for you. Otherwise the jumpers are set to ignore ignition as a default.

As Jim pointed out, switching main power is touchy (especially if it's a 100W radio) and I should have mentioned it. Hooking it to a fuse block, or even a heavy duty toggle switch is going to give you probs. You have to think beefy. A relay should be used. Those 30A ice cube relays at a minimum, but I like the 75A Bosch relays.

A lot of fire departments run 790's and they are wired to the main switched power buss in the engine. No ignition sense lead is used and they turn on by themselves and play fine.

You can hook up your 690 either way, the choice is yours.