Something kind of odd

Ok as of late, I have been fighting hgiher then normal swr issues on my truck. My SWR always stayed real close to 1.5 to 1 until lately. I got to checking and found a faulty coax. I could move the coax at the back of the radio and my SWR would spike to well over 3:1. Replaced it.

I even bought new whips for my 5000s since I had trimmed them too much when I first got them. Very little of the antenna was engaged into the mast. I put them in the other day and had a perfect 1.5 across the board with no trimming needed. I started the truck and was moving down the road and noticed that my swr had jumped to about 2.5.

Hmm that is odd. Well last evening I was going over the grounds on the truck etc and after a little bit my SWR was back down to 1.5 again. It was getting warm in the struck so I started it back up to run the AC a bit and after just a short bit my SWR was back above 2:1. As the truck ran it slowly climbed to just under 3:1. I shut the truck off and after a few minuted the SWR was back down to 1.5 again.

I am thinking that possibly the voltage regulator is going bad in the alternator on the truck. I have noticed that my truck voltage has been running a little higher then normal. Usually it runs right at about 13-13.5 volts running but lately it has been running right around 14 volts or just a tad under. I questioned our shop about my higher voltage and they did not seem concerned about it. Their thinking is that as long as it is not spiking about 15 volts then everything is fine as long as the truck is still running fine. I do know that when I was turning wrenchs on cars etc, back in the day, that an over charging system would turn on the CEL (check engine light) and it would turn on the battery light. Off hand I can not remember what voltage it was that would kick on the lights.

I thought that the radios had their own regulators in them also to keep them from over volting, Could it be that I also have an internal regulator that is starting to fail????

I am going to question the boss this morning on the condition of the alternator and see what he thinks. I don't think he would like the idea of possibly cooking the brand new bats that were installed about 6 months ago.

 

I have two external meters also and have checked the meter in my radio against both meters and they all read the same. So I am not too concerned about the internal meter on the radio since it reads the same as both my external meters.


As far as checking the grounding system, well went over it again today while I was waiting. They are clean and everything is properly grounded acording to my Digital Fluke multi meter.

Running down the road and SWR is high, turn on all the lights,High beam,sleeper lights, bunk fan, cab fan and everything I can think of. Voltage drops and so does swr.

Possible internal voltage regulator problem on the radio????

Going to dig around in my garage and see if I can find another radio to slap in tomorrow and see if the problem persists. I want to make sure before I put my connex 4600 turbo back up.

 

Cobra 29, 04 peterbilt 379, I am not running the facotry coax setup and I am running aftermarket antenna mounts rather then the stock mounts. I have been doing all testing while stationary.

 

I have been tapped into the batteries since I got this truck 4+ years ago. I am tapped in using 8 guage wire for both power and ground. Both are also fused.

I added extra grounding for the doors, hood, cab and anything else that is metal on the truck a few years ago also. Everythign has been good up until late.

Sitting in yard with the motor off = 1.5:1 start the motor and it slowly climbs to about 3:1. Turn the motor off and it will stay at 3:1 until I turn on all the lights etc to draw the batteries down a tad and everything is back to 1.5:1 Well 40 is just a dash under 2:1. It used to always stay less then 2:1 even moving down the road with the whips whipping in the wind.