mobile/antenna power problem

[Golson2210]

I have a mobile scanner mounted on the trunk of my vehicle with BNC cable run up to the front dashboard area which connects to a small BNC to SMA pigtail. I also have a 3 socket cigarette lighter adapter which the scanner plugs into. Everytime I connect the antenna pigtail to the scanner, the power to the cigarette lighter adapter turns on. The whole point of the adapter was so power wasnt constantly running to the adapters while the car was turned off. Since both the scanner antenna and GPS antenna have a small red LED light, didnt want that to drain my battery since Chevys dont shut the power off to the cigarette lighters when the car is off.

Any suggestions on fixing this antenna problem so it doesnt turn the power on to my accessories when connected to the scanner?

 

[sfd119]

I have two cig USB charger deals with the LED indicators in my truck. They are always on and I have not drained a battery yet.

 

[wogggieee]

I dont think you're in jeopardy of draining your battery unless you have an already weak battery. If you're really concerned test the battery voltage with a meter a few minutes after you turn the car off for the night and then again in the morning, if the voltage drop is only a few tenths you'll be fine.

Otherwise the simple solution is to unplug it when its not in use or get a switched cig plug for it.

 

[r_eugene1]

I have a mobile scanner mounted on the trunk of my vehicle with BNC cable run up to the front dashboard area which connects to a small BNC to SMA pigtail. I also have a 3 socket cigarette lighter adapter which the scanner plugs into. Everytime I connect the antenna pigtail to the scanner, the power to the cigarette lighter adapter turns on. The whole point of the adapter was so power wasnt constantly running to the adapters while the car was turned off. Since both the scanner antenna and GPS antenna have a small red LED light, didnt want that to drain my battery since Chevys dont shut the power off to the cigarette lighters when the car is off.

Any suggestions on fixing this antenna problem so it doesnt turn the power on to my accessories when connected to the scanner?

Unless I misread the post I do not see how the red LED on the cigarette lighter adapter can turn on by connecting a pig tail to the scanner. I have used pig tails before and have never had any light/led come on ever. Maybe I am missing something, as for draining the car battery it is highly unlikely (MHO).

 

[Napsterbater]

Unless I misread the post I do not see how the red LED on the cigarette lighter adapter can turn on by connecting a pig tail to the scanner. I have used pig tails before and have never had any light/led come on ever. Maybe I am missing something, as for draining the car battery it is highly unlikely (MHO).

Grounding issue, I had a similar issue when I had my Laptop powered by a 12v power adapter and plugged it up to my ham radio with a USB to serial cable, but if I use an inverter and a 120v power adapter for the laptop it didn't.

Basically power is finding a ground through the lighter and going trough the LED to ground thus tuning it on.

 

[WA0CBW]

Sounds like the 3 socket device doesn't have a ground. Connecting the antenna provides the ground through the scanner to the scanners power cord which grounds the 3 socket device.
BB

 

[NDRADIONUT]

The steel parts of the car provide the -12v so anything that gets connected gets power...
If you want to be isolated from the car body then run wires directly to the battery and don't connect anything to the car itself.