Little Tweaks

[Rooster73]

Originally Posted by Lightninrod

I used the finger-tightened radio mounting-to-the-bracket 'bolts' to ground the radio's chassis. Those bolts tighten into the chassis holes. I used a star, locking washer between the radio's case and the ground strap. I attached the other end of the strap to a bolt in the front of the passenger's seat that bolts the seat to the truck's body.

I'd watch that source as a grounding point.

From my car audio days, I've seen way to many people hook the amp gound wire to the seat bolts and then wonder why the amp light drowns out with every bass signal passed through the amp.

I would go directly to the frame or body, grinding the paint away and then attaching the ground cable.

When in doubt, Ohm the grounding point to check for resistance.

[Lightninrod]

Did check for '0' ohms and this was the radio's chassis, not an amp.

[Rat]

If you open up a radio and look at it, you will notice that the board and chassis of the radio are tied to the ground in the plug. So grounding the chassis of the radio is not needed. It does not help anything.

Oh and you ground the antenna bracket not the antenna itself.

[Hedgehog6973]

I hear a lot about grounding the CB its self to the frame , ok what i have done b4 i even knew this is i mounted my cb to the ROOF of my 4x4 its bolted right threw the case its self to the roof , for security reasons, so is that a good ground or should i run a 3rd wire to the cb and down to the frame ??? i have a noise filter on the power lead, and i run a 102 whip ,so is my cb ground good enough ? and i have a lot of squelch almost 7 on the meter and the light dips when i modulate on a midland 77-857, why is this , please help thanks a alot , Don

[FriedTater]

Many Freightliner installs later . . . . .
Not true !
External Radio Chassis grounds do help in this plastic world of ours.

No such thing as to much grounding,makes for a much quiter Cobra/Uniden radio .

Originally Posted by Rat

If you open up a radio and look at it, you will notice that the board and chassis of the radio are tied to the ground in the plug. So grounding the chassis of the radio is not needed. It does not help anything.

Oh and you ground the antenna bracket not the antenna itself.

[K2DMG]

Originally Posted by Rat

If you open up a radio and look at it, you will notice that the board and chassis of the radio are tied to the ground in the plug. So grounding the chassis of the radio is not needed. It does not help anything.

Oh and you ground the antenna bracket not the antenna itself.

You obviously don't no a darn thing about radio and grounding. If you don't have any idea what you are talking about you should not speak on that subject. Grounding the radio and antenna make a BIG Difference. Please read this article at, [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. maybe you will learn a little bit about radio before you shoot your mouth off about something you no zero about.

Basics

Bonding, sometimes referred to as strapping, is one of the three most important aspects of mobile radio. [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. and [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. are the others. There are several reasons for this. First is noise abatement. Bonding minimizes the leakage of RFI into (ingress) and out of (egress) the various bolted on parts of the vehicle. The exhaust and tail pipes are good examples of RFI egress. It is not uncommon to see a 20 to 30 dB drop in received noise levels once they're properly grounded.

The best mobile antenna money can buy, isn't any better than the ground plane it is mounted over. Maximizing the available ground plane is what bonding is all about. On the HF bands, our vehicles act more like a capacitance to ground, rather than a ground plane. The bonding doors and trunk lids has a lessor effect on noise, but does aid in maximizing the ground plane If you doubt this reasoning, here's a little experiment you can try.
Install your antenna first and use an MFJ 259B or similar antenna analyzer to measure the on-resonance (X=Ø) input impedance of your antenna. Then follow the suggestions below and once you're done, measure it again. The resonant point will drop slightly and the input impedance will drop perhaps as much as 25 percent. This occurs because bonding lessens the ground losses which are reflected in the input impedance. The better the quality of the antenna, the more noticeable the change will be.
Here is a money saving tip. If you don't intend to properly bond your vehicle, you can save a lot of money by buying a cheap antenna. The basis behind this is simple. If ground losses are high, it doesn't make much difference how good the antenna is, because ground losses will be the largest factor in determining efficiency. If ground losses are low, the difference in efficiency between a cheap antenna, and a good one become very apparent.

Ground Straps

One of the most misunderstood concepts is the difference between DC and RF ground (neither one can be considered a ground plane). A ground strap may work perfectly as a DC ground, but at some frequency that same ground strap will make a perfect antenna! We all know that an inductor can provide a good DC ground, but look like an open circuit to RF. And that a capacitor can provide a good RF path to ground, but not a DC path. Our ground strap, like any piece of wire, has both inductive and capacitive reactances. These reactances change as the frequency changes. For any given value of reactance, as the frequency goes up, inductive reactance (in ohms) also goes up, but capacitive reactance (in ohms) goes down. When inductive reactance and capacitive reactance in any given piece of wire are equal, that wire will become an antenna, and ceases to be an RF ground. There are a few things we can do to assure both a good RF and DC ground.
One of these is to use braided wire. Not just any braided wire mind you, but one which is flat and wide. RF flows at the surface rather than through the wire, and flat braid has more surface area for any given current carrying capacity. Thus it provides less resistance to RF than an equivalent round wire. It also has more capacitive reactance which increases the self resonant point. Flat braid is also much more flexible and less likely to fail due to repeated flexing.
The shield from RG8 works well if the length of the strap is short (under 10 inches or so). Just take care when you strip off the outer jacket that you don't cut through the shield itself. Discard any that is corroded or discolored. Flatten it out by pulling it over a rounded surface. A large, round screwdriver shaft works well for this purpose.
For longer lengths, one inch wide braid is a better choice. In any case, the requisite length shouldn't exceed 2 feet. If it has to be longer, then heavy copper flashing, like that used by roofing companies, is the material of choice. Remember, the ground strap must present a low impedance connection to effectively shunt RF to ground. This is especially true if you're using an auto-coupler, as the ground side connection must have a (much) lower impedance than the radiating element. I cover this in more detail in my [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. article.
Good connections are also important to provide both a DC and RF ground path. Crimping and soldering are mandatory. Crimping provides a good mechanical connection, and soldering a good electrical one. Good quality lugs and connectors are a must too, as the cheap ones do not solder well. Where applicable, connections should have heat shrink applied over them. Although not strictly necessary, it gives a finished and professional look to your installation.

[Carolina Thunder]

Originally Posted by K2DMG

You obviously don't no a darn thing about radio and grounding. If you don't have any idea what you are talking about you should not speak on that subject. Grounding the radio and antenna make a BIG Difference. Please read this article at, [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. maybe you will learn a little bit about radio before you shoot your mouth off about something you no zero about.

I second that. No matter if it's base or mobile install, you ground the hell out of everything!

[WA4GCH]

Maybe i'm a bit old but i still use my PALOMAR NOISE BRIDGE to tune my HF antennas ......

[outerspacehillbilly]

Great post K2DMG, that was some very useful information that most could definitely use and benefit from.

[oh well]

I have a Midland 1001Z (was peaked) with a 4ft fiberglass antenna using RG8X 95%coax. I only get out about a mile and a half. So if I understand this the radio need to be grounded. Would a different antenna work better? Also when I turn the wipers on the radio picks up the wipe motor.