Braided ground strap to reduce radio interference?

[Ed_Flecko]

I have a book on automotive electrical systems and the author says, "The braided strap also dampens out some radio-frequency interference that otherwise might be transmitted through standard stranded wiring due to the skin effect." There's also an accompanying photo with caption that reads, "braided ground strap used to ground the hood to reduce radio interference" and it shows the ground strap running from the hood to the firewall.

I'm always looking for ways to improve my radio reception and sound so I'm wondering if these statements are true, and is it worthwhile for me to add a braided ground strap from my hood to the firewall? Do you think it would make a noticeable improvement?

Thank you,
Ed

 

[SrDriver]

Back in the CB Radio days this was done to various parts of vehicle to reduce interference. Will not hurt anything.

 

[NHGUY]

Chrysler products up though the years used one standard equipment.Thats good engineering!

 

[Quest]

braided ground straps usage on car grounding purposes example: hood to chassis, mainly for the sake of it's flexibility properties, not for RFI grounding purposes.

This is especially important for applications that exhibits lots of twisting or vibrations where solid core/large gauge wires would suffer from metal fatique and break.

braided spark plug wires would help immensely, but then again: resistor spark plugs would do just fine.

Nowadays, with coil over plugs configuration, there's no big issues when overcoming the spark ignition related RFI issues.

Q.

 

[Jimmy9190]

It can help keep out radiated noise from the ignition system and main wire harness under the hood, especially when listening to AM radio. With FM, you may not see any improvement unless you have a high energy or high performance ignition system to begin with. As the others said, it can't hurt anything to have the hood and firewall grounded to the engine block with the braided straps or even just plain old 10 gauge insulated copper wire.

 

[Ed_Flecko]

Originally Posted By: Jimmy9190
It can help keep out radiated noise from the ignition system and main wire harness under the hood, especially when listening to AM radio. With FM, you may not see any improvement unless you have a high energy or high performance ignition system to begin with. As the others said, it can't hurt anything to have the hood and firewall grounded to the engine block with the braided straps or even just plain old 10 gauge insulated copper wire.


Thanks Jimmy!

That's kind of what I'm hoping is that I might see an improvement with AM radio, because I listen to that probably as much, if not more than FM radio. There's even some stations that I don't receive very well (due to how far I am from the broadcasting station) that I'm hoping a ground strap might help with, but probably not - I suspect that's a reception issue and not an interference issue, so I'm not expecting that a ground strap would help that. It would be great if it does...but I'm not expecting that.

Ed

 

[Jimmy9190]

It will help on radio noise to use radio noise supression core spark plug wires and resistor type plugs, use a good solid clean ground for the radio and clean the underside of the mounting area for the antenna. There used to be antenna noise suppressor filters you could buy to plug inline on the antenna coax cable to choke out AM and FM noise, you may still be able find one on Amazon or at Crutchfield. It also will help to keep any main wire harnesses in the dash away from the case of the radio as best you can. Reception will depend on the radio itself and the condition of the antenna.

 

[1 FMF]

just because some author wrote a book saying that, does not mean it is true.

what is most likely true is they use as many angles as they can to help sell a product. claiming it: reduces skin effect for RF interference... helping flux capacitor efficiency and reducing quantum variance and reactance yada yada whatever else.... it's a lot of technobable you don't understand but it exploits your sense of hope because you can't prove that technobable wrong.

skin effect is taken completely out of context and used wrong in what they are trying to "claim" it does and/or prevent. or the point i'm trying to get across is putting a "braided ground strap" on your hood to improve radio reception about as good as me turning my cell phone off to reduce transmitted RF signals that might be causing interference with your radio reception.

what kind of car, where is your antenna located? if it's laminated within the back window then that may be part of your problem. or it may simply be the radio receiver in the dash is junk, and has nothing to do with your radio antenna gain and noise floor.... which is what you want to measure to know where your problem actually lies.

 

[Yah-Tah-Hey]

Conductivity is conductivity whether it's braided, stranded or solid. Only difference if flexibility.

 

[redbone3]

Originally Posted By: HosteenJorje
Conductivity is conductivity whether it's braided, stranded or solid. Only difference if flexibility.


Not exactly correct. With high frequencies the RF tends to conduct on the surface of the conductor (Skin Effect). It is entirely possible that a strap could have more surface area and conduct RF energy better. The higher the frequency the more pronounced the "Skin Effect" is.

 

[Quest]

I must tell you something folks, for the following:

How many of you haven't seen the existence of an extra grounding strap that ties the chassis up to the metal hood? I personally have not seen any for over 25 yrs now, and I don't even believe I've seen that applied to factory metal hood from chassis, period [hinges are made of metal, which conducts electricity BTW].

braided grounding straps are mainly used where flexibility and vibration are of serious concern, i.e. chassis to engine, etc. Also: most of the factory manufactured automobiles have their grounding all worked out properly already, i.e. where to apply certain grounding schemes to minimise noise from introducing into the ECU, etc. and sparking systems already have that part all worked out.

Adding unnecessary grounding to EFI cars was a fad back in the 90s, but eventually died off due to the fact that when overdone, the benefits is minimal, if any. Some may even become counter-productive.

For car radio, it's a different story. Most factory radio already has grounding all worked out nicely. Aftermark head units, amps, preamps, etc. sometimes will have grounding-related hum/buzz noise due to ground loop. RFI related noise has not been an issue in automobile world since the early 80s, as the wide adaptation of noise-suppressing (resistor) spark plugs, etc. and the industry-wide adaptation of solid-state spark ignition circuitry (where noise can be easily suppressed than point and capacitor type).

Those days are gone, and I have yet encounter one single radio (factory radio of course, cars involved into certain frontal accidents need not apply for the body shops typically cut off ground straps to facilitate their repairs). If you have buzz in AM part,then it's your radio and your antenna's grounding issues, and start looking from that angle.....

Just don't come along and assume braided grounding straps will do miracles if you don't even know what you are dealing with.

Q.

 

[wrcsixeight]

For improving the antenna signal, Try some Caig DeOxit D100 to clean all Deoxit Gold or Shield to protect the cleaned contacts.

http://www.amazon.com/CAIG-SK-IN30-DeoxI...p;keywords=CAIG

This stuff has helped my OTA TV antenna receive stronger signals when applied to each and every RG-6 F connector and gained me a few % on all available Wifi signals as well.


I'll never re attach any electrical contact without a cleaning with D5 or D100 and an application of Gold or Caig Shield to protect. Conductivity actually improves with time after application of gold or shield.

What it was able to remove from my ECM's pins and connector sockets, after a thorough cleaning with CRC QED electronics cleaner, was astounding.