Sirio 5000 and Wilson 5000

[binrat]

I've never touched a Cobra, Uniden, Galaxy, Ranger or General that had the chassis and board tied together at DC ground. The link Connor shared months ago from W8JI showed exactly what I'm talking about and he refused to see it. It just isn't there.

Is this really a problem?? Like it happens multiple times a year to radios?? Are the vehicles that people install radios in this bad of shape?? I see it as a perceived problem by some.
Personally I run power and ground from the battery as its the best and easiest place to find it on the newer NA vehicles. I also have both sides fused at the battery.

 

[GnG8d]

Is this really a problem?? Like it happens multiple times a year to radios?? Are the vehicles that people install radios in this bad of shape?? I see it as a perceived problem by some.
Personally I run power and ground from the battery as its the best and easiest place to find it on the newer NA vehicles. I also have both sides fused at the battery.

You aren't paying attention and following along.

 

[binrat]

You aren't paying attention and following along.

Well, yes and no.
The debate the way I see it is "that if you run ground from the battery direct then your vehicle may start getting its ground through your radio" as someone feels that certain radios DC ground (or not).

 

[GnG8d]

Well, yes and no.
The debate the way I see it is "that if you run ground from the battery direct then your vehicle may start getting its ground through your radio" as someone feels that certain radios DC ground (or not).

Correct. Connor thinks radios have their boards connected to their chassis at DC, and I've never seen one built that way.

 

[222DBFL]

I have always been told grounds should be as short as possible and go to frame, I always use a seat bolt. Going to the battery with both leads may not create the best ground as most newer vehicles have shitty grounding. My Nissan NV work can had every ground for electronics for the vehicle with paint behind the contact. I had to take at least 15-20 connections off and sand the area down and add some no-ox. I have tried the negative to battery before, but IMO, a short ground to the frame is the best. JMO.

 

[222DBFL]

But I will say some radios actually say to use both pos and neg terminals. I just prefer the short ground to a seat post bolt, I know that it's grounded!! Like said, most newer vehicles have a shitty grounding network in my experience. Older vehicles have heavier metal and are usually made better. There used to be some pride in quality, anymore it's let's make all the money we can and screw the customer!!! Look at all the recalls lately and you will understand. Anyway, god bless.

 

[Tucker442]

My ground for my radio goes from the radio wire, direct to the bracket that holds the dash assy in place by the inside of the door, no extra wire needed.

 

[222DBFL]

Not sure about the numbers tucker, can't log numbers and drive lol. But I am sure I spoke with 1 or more guys in NJ, the other day. 222 mobile around the state of FL. I say that as I travel for work and do my dx'ing while driving from cell site to cell site.

 

[GnG8d]

With all these safety crush zones, the seat bolt may not be grounded at all!

 

[loosecannon]

No they're not. Put your continuity tester on the negative cable and touch it to the chassis of the rig.

Here's a Cobra 148. Top right corner. Look at where the screw that holds the PCB onto the tabs on the metal case is connected to. They even put solder on the tabs to ensure a good connection.

http://www.cobraworxshopz.com/images/JD_CUSTOM_SX-1_PRINT_SIDE_PCB.jpg

Next go to the bottom right corner. Notice the pads for other components on the same track the pcb retaining screw is electrically connected to.

Galaxy 959..similar thing.

http://www.netdestiny.com/radio/DVC00067.JPG

Magnum S9

http://i820.photobucket.com/albums/zz128/astradyne1/omega007.jpg

Want me to go on?

And then there's the fact the chassis is also electrically connected to the body of the car, the same thing that all the electrics in the vehicle use for a connection to ground.

M0GVZ,
i think you need to look at those pics a little closer.
the chassis is indeed isolated from PC board ground in all the pics you showed except for the last one.

i believe that the radios that have built in amps do have the grounds tied together.

the two grounds are connected through ceramic disc caps.
they are AC coupled, but not DC coupled.

99% of legal Cb radios are like this because some big rigs have positive ground systems.

i think the only CB ive seen personally that had the chassis and PC board grounds was a cobra 19 plus.

ham radios on the other hand usually have the grounds tied together.


LC

 

[M0GVZ]

Correct. Connor thinks radios have their boards connected to their chassis at DC, and I've never seen one built that way.

What radio do you own? Certainly the Cobras, the Magnum S9 and others I've come across are.

 

[M0GVZ]

And there is NO continuity there. You're looking at pictures and it's got you confused. Connect the ground of you meter or scope to the chassis and try to set DC voltages on the board and get back to me.

I have frequently. The last one I aligned using the ground clip connected to the chassis was a President Lincoln. Checking alignment of the radio on my Marconi 2955 and my Rigol DSA815 showed it to be spot on.

Watch all the videos this guy does of repairing CBs. Every single one of them he uses the chassis as a ground connection for the test equipment.

https://www.youtube.com/channel/UC6w677p4ucVOw2VxqZk-UlA

All the CBs, all the commercial radio gear from Kenwood, Icom, Tait, Simoco, Vertex Standard and all the amateur radio gear from Kenwood, Icom, Yaesu, Alinco, FlexRadio I've worked on over the years which is probably a lot more than you have, have all had DC continuity between the 0V wire and the chassis. All of them. Without exception.

I'm doing a honours degree in electronics engineering after being a qualified electronics engineer for 27 years. I think I may have a bit of a clue than some random CBer whose just bought a $10 30 year old scope from Ebay. What are your electronics qualifications?

 

[M0GVZ]

I've never touched a Cobra, Uniden, Galaxy, Ranger or General that had the chassis and board tied together at DC ground. The link Connor shared months ago from W8JI showed exactly what I'm talking about and he refused to see it. It just isn't there.

This link here from W8JI which explains that all the current flows through the radio if there's a problem with the main vehicle ground connection and you've wired directly to the negative?

http://www.w8ji.com/mobile_ground.htm

Its half way down the page....

If the battery to engine block ground opens, or the engine block and battery to chassis grounds open, the battery will ground back through the negative radio connection to the radio, through circuit boards or other connections, and to the vehicle chassis.

 

[GnG8d]

When you get finished thumping your chest, you'll see that you gave Trucker442 bad advice Connor.

 

[binrat]

When you get finished thumping your chest, you'll see that you gave Trucker442 bad advice Connor.

But the big question is.
Connor with all this "your radio is going to have instant death nonscence" have you every witness first hand such demise of a radio??