Survey Comments
Looking for answers? ...... no......
N9WQ--not 'looking' for an answer, just opinions. I don't believe ASE makes anyone an expert on radio wiring--but your reasoning is why some DO fuse the neg. lead!
Posted by
K1CJS on 2006-06-27
And then.....
NA1SV....There are also some older cars that have really lousy ground paths as well, sometimes just from age and lack of maintenance. All the more reason to run directly to the battery.......
Posted by
K1CJS on 2006-06-27
Fusing the Negative
Sorry to bump into this subject so late, but...
I believe those who said "if you use a short ground lead, *not* going to the battery, no need to fuse. I agree that in that case, there's no need for the ground fuse.
So why go all the way to the battery with your ground? Simple... years of experience with older cars doesn't help out in the brave new world we're now in. Our radios produce high output power - 50, 75 and 100 watts, and need to draw high current - higher than we used to see since the age of the tube Motracs ended (in those days, every vehicle had a real frame!). Nowadays, we aren't talking about steel-framed vehicles with steel bodies anymore. I'm not confident about the quality of that ground return... And, I really don't want to share the ground return path with the starter if I make the mistake of leaving my radio on while starting the vehicle. And some radios (like my TM-D700A) are never really "off." By running both + and - to the battery, I get to use the battery's capacitance to help dampen spikes that inevitably occur when the starter is operating. If I use the vehicle frame only, then I'm sharing the last part of the path with the starter current. For the fellow who connected to the vehicle frame instead of the battery post itself, you still have the same problem. I know, I know - the radio is *already* grounded through its mounting to the vehicle, and perhaps through its antenna connection - although on VHF there are some "no ground required" 1/2 wave antennas for VHF or UHF that are often used on ambulance roofs, for example. No ground return there. My challenge is to make my ground return a lower-impedence path to the battery than the other paths available, so that my return current flows the way I want it to.
Summarizing: Modern cars = unpredictable current flow through the vehicle shell, and as for sharing a current path with the starter... No, thanks! I'll run both power and ground to the battery, and since I'm doing that, I'll fuse the ground.
73 from Steve NA1SV
Posted by
NA7SV on 2006-06-22
fusing the power leads
Always!!! I fuse the negative and positive leads on all my mobile equipment. IN fact, I have one set of fuses at the battery (within 2 ft) and one set just before the radio. Never say never when talking about power problems. I also ground the equipment. My HF in my truck has a line isolator on it to ground.
This way if something happens, I know I did what I could to prevent much of this happening.
Posted by
N4KRA on 2006-06-02
negative fues....
here is the answer that you boys are looking for....... ready... ok lets think a little
in the case of the amateur radio the reason the neg would be fused at all is if it were subjected to a groundless circumstance like a boat or other groundless installation. if you use the fused negative in a grounded enviroment
and the neg fuse blows then the radio can act as a path for startor motor or whatever high current drawing device (like giving the wifes car a jump ) with a bad ground strap between the body of the car and the battery the negitive fuse in radio lead may blow from the current and then thats where the problems begin... the radio still works becaus its getting grounds from the antenna connection and mounting so when the fuse blows it forces the current to find a path thru the radio.
so I would always recomend connecting the radios ground lead direct to the battery WITHOUT a FUSE because the pos is fused and this is a DC system. the reason is boats and fiberglass cars ASE tech 30 years
Dave N9WQ
Posted by
N9WQ on 2006-04-04
negative fues....
here is the answer that you boys are looking for....... ready... ok lets think a little
in the case of the amateur radio the reason the neg would be fused at all is if it were subjected to a groundless circumstance like a boat or other groundless installation. if you use the fused negative in a grounded enviroment
and the neg fuse blows then the radio can act as a path for startor motor or whatever high current drawing device (like giving the wifes car a jump ) with a bad ground strap between the body of the car and the battery the negitive fuse in radio lead may blow from the current and then thats where the problems begin... the radio still works becaus its getting grounds from the antenna connection and mounting so when the fuse blows it forces the current to find a path thru the radio.
so I would always recomend connecting the radios ground lead direct to the battery WITHOUT a FUSE because the pos is fused and this is a DC system. the reason is boats and fiberglass cars ASE tech 30 years
Dave N9WQ
Posted by
N9WQ on 2006-04-04
An offer I can't RE-FUSE
I've had my TMv7 Kenwood wired with postive & negative fuses to the battery for about 10 years without a single blowout from either side. Not a bad idea especially on higher powered mobiles that pull more amps.
Posted by
AD5KL on 2006-04-03
An offer I can't RE-FUSE
I've had my TMv7 Kenwood wired with postive & negative fuses to the battery for about 10 years without a single blowout from either side. Not a bad idea especially on higher powered mobiles that pull more amps.
Posted by
AD5KL on 2006-04-03
Fusing the Negative
Okay guys, listen up, here is the straight scoop!
If you ground the rig to the body of the car directly there is no need to fuse the negative lead. BUT! If you connect both the positive and negative leads from the radio to the battery be certain the negative lead is fused.
WHY?
Chances are almost 100% the negative lead attached to the radio is also connected to the radio chassis. If the heavy gauge lead (that came with the car) from the negative post of the battery to the chassis should develop high resistance or fail then the alternate path is through your radio-since it is connected to the body of the car.
Has this happened? Yes! I have repaired many GE Master II and Motorola Micor mobiles that were installed in the world's worst fleet of Taxicabs. Who ever installed the rigs didn't fuse the ground lead which was brought back to the battery. After 200,000 miles and 10 years and a load of questionable maintenance on these cars the ground lead would deteriorate to the point the lowest resistance return to the battery was through the radio.
Do you really want to risk vaporized traces on the circuit board or trashed outputs and low pass filters?
BOY !!!! DO I HAVE TO AGREE WITH THIS ONE...
Keep in mind if you run both positive and negative leads to the battery, then after years of driving, have the negative wire fail from the battery to the body of the car, the entire car will be using that unfused negative lead connected to that radio. And if that antenna, you mounted on the body is connected back to the PL-259, that may be the ONLY grouned your car now has... Fuse it fokes....
Posted by
K8BBE on 2006-04-02
They said it all!
AA4PB and K8BBE, and many others have said it all! Smart hams fuse both leads.
Now let's get on with the next survey question, and ignore the scoffers, grumps and doomsayers who feel the need to inject their complaints and wails into every opportunity that comes their way.
Posted by
AI2IA on 2006-04-02
kg4rrn
maybe if the following was sent a copy of what
was posted by kg4rrn they would be very impressed.
........................................
I am a member of the following ham radio clubs...
Fairfax Co.VA., Loudoun Co.VA., Jefferson Co. WVA ARES Former RACES (one year only) VWS, AMRAD, NVFMA, NCAC. Co-Moderator: Yahoo Group V82/U82
......................................
"IDIOT PROOF Battery Leads- A grand Idea in the Age Of Dumbing Down, and NoCode Generals
coming up. Prepare for the future..upgrade today ! You will be glad you did. The 2 meter CBers are coming !!!
Posted by KG4RRN on March 22, 2006"
..........................
Posted by
KC7AZG on 2006-04-01
It depends
If you connect the radio's ground lead directly to the negative battery post then it should absolutly be fused. If you connect the radio's ground lead to the chassis somewhere then a negative fuse is pointless.
The reason for the negative fuse is that if the vehicle's battery negative lead has a poor connection then starter current will flow thru the radio's negative lead to the radio chassis and to ground thru the mount or antenna. The negative fuse protects the radio's negative wire from the heavy starter currents.
Posted by
AA4PB on 2006-03-31
Perfect example
KG4RRN's comment below is a peferct example of why ham is in the crapper. This type of attitude will ensure ham radio's early deminse, not the reduction in testing requirements. God its really sad when someone can take a technical discussion on a topic like battery grounding and start a no-code bashing sesssion.
Eric KC5FOG
"IDIOT PROOF Battery Leads- A grand Idea in the Age Of Dumbing Down, and NoCode Generals
coming up. Prepare for the future..upgrade today ! You will be glad you did. The 2 meter CBers are coming !!!
Posted by KG4RRN on March 22, 2006"
Posted by
KC5FOG on 2006-03-31
SURVEY
INTERESTING ITEM: ENJOYED READING ALMOST ALL COMMENTS. KE6PID covered it correctly, as did a few others. This was for enlightment/education and was served well.
EXCEPTION was the post by KG4RRN who omitted the subject matter probably because of his lack of knowledge, INSTEAD posted his derogatory remarks NOT related to this surveys subject.
Charlie; KE4FES
Posted by
KE4FES on 2006-03-25
Fusing the Negative
I have Worked in the radio business for over 30 years. I always make the negitive lead as short as possible and ensure a good connection to the chassis. This will ensure the antenna reference point is as close possible to the chassis potential. In addition this will help reduce non-ionizing radiation inside the car, as well as receiver interferance.
Posted by
N1BOK on 2006-03-24
Well, one reason for fusing both sides is because that's what the auto manufacturers recommend, and not wanting to void a warranty, I do what I'm told.
If I can find a reliable ground someplace close to the radio, I will have to try the other approach some day, to see if noise performance is improved.
I've seen the ground strap on a battery fail, and the negative lead from the radio become the only path for ground return between the battery and the chassis and starter. Now, however, if you ground the negative lead to the chassis and not the battery, I think that would eliminate the problem, since if the ground strap fails, the chassis will not be connected to the battery, anyway.
Posted by
K0RGR on 2006-03-24
why bother !
never have fused neg lead
radio is bolted to ground
antenna feed
coax shield is grounded
mac dit dit
Posted by
W8ZNX on 2006-03-24
fuse it!
Okay guys, listen up, here is the straight scoop!
If you ground the rig to the body of the car directly there is no need to fuse the negative lead. BUT! If you connect both the positive and negative leads from the radio to the battery be certain the negative lead is fused.
WHY?
Chances are almost 100% the negative lead attached to the radio is also connected to the radio chassis. If the heavy gauge lead (that came with the car) from the negative post of the battery to the chassis should develop high resistance or fail then the alternate path is through your radio-since it is connected to the body of the car.
Has this happened? Yes! I have repaired many GE Master II and Motorola Micor mobiles that were installed in the world's worst fleet of Taxicabs. Who ever installed the rigs didn't fuse the ground lead which was brought back to the battery. After 200,000 miles and 10 years and a load of questionable maintenance on these cars the ground lead would deteriorate to the point the lowest resistance return to the battery was through the radio.
Do you really want to risk vaporized traces on the circuit board or trashed outputs and low pass filters?
Posted by
KE6PID on 2006-03-24
negative lead
All the more reason NOT to run the negative lead directly to the battery post in the first place...
Posted by
KC8VWM on 2006-03-24
Commercial radios dont.
I have always grounded with a very short heavy ground lead to chassis ground near the radio. Like Motorola and other commercial radios do. (NO negative fuse) And then make sure that the battery negative lead to chassis and frame is all well bonded together. I see no point to running a negative lead all the way to the battery. Positive only.
However, If I have a newer radio that has both positive and negative fused, I leave it in the line........
Posted by
K9KJM on 2006-03-24
KG4RRN
IDIOT PROOF Battery Leads- A grand Idea in the Age Of Dumbing Down, and NoCode Generals
coming up. Prepare for the future..upgrade today !
You will be glad you did. The 2 meter CBers are coming !!!
Posted by
KG4RRN on 2006-03-22
Negative lead fusing
Today, many of the locations for mounting a dash mount radio are non metalic, thus a ground lead is necessary. No one knows when the radio is built, just how long the negative lead needs to be to reach ground. The manufacturers were the ones who decided to add the negative lead fuse, for the reason I outlined earlier. If you want to cut it off short and go to chassis, do it. If not, go to the battery negative post or nearby. Your call. The results you obtain are your responsibility. The fact that you've never experienced this or that problem really has no bearing on anything. Over the course of a lifetime, if you pursue good practices, you'll avoid many problems. If not, you'll experience many. Your decision.
Posted by
WA4DOU on 2006-03-21
Negative in-line Fuse
I have to agree with VE1PGC and N3EG, The chasis is usually grounded, if not from the mount, then from the antenna!
And again, I always run the shortest possible route of ground, and I use about 3 to 6 turns in a ferrite "donut" on BOTH leads also, and this does keep any engine noise to none or only noticeable on FULL volume, and is still nil!
But I will not critisize anyone for how they install, the saying is an old cliche', but to each his/her own!
Posted by
KG4BVD on 2006-03-21
I work in a two-way shop, and we ALWAYS ground to the closest metal surface we can stick a screw into, and use a star washer as well. I've personally compared the amount of noise and crud on a HF radio with a long ground lead vs. a short one, and the short one can be up to 20db better. Also, you have half the voltage drop. I've never spiked a radio or burned an internal ground.
Posted by
N3EG on 2006-03-19
I work in a two-way shop, and we ALWAYS ground to the closest metal surface we can stick a screw into, and use a star washer as well. I've personally compared the amount of noise and crud on a HF radio with a long ground lead vs. a short one, and the short one can be up to 20db better. Also, you have half the voltage drop. I've never spiked a radio or burned an internal ground.
Posted by
N3EG on 2006-03-19
Negative Fuse
Hello,
I have seen over 30 plus radios with the ground burnt from reverse contact's being made. ALL RADIO’S need a fuse of the proper rating and your covered. Ground is all over. It only takes one time to kill the radio. Please don’t foil wrap a fuse. Big no no !!! If there is ever anything gone wrong you will know. It is cheap, easy and covers nearly 100% of the radio.
73’s & Take care
Posted by
KB3MTU on 2006-03-18
fusing the negative
it doesn't matter the radio chassis is grounded anyway so ooo what is all the fuss about fused or not the thing is still grounded
Posted by
VE1PGC on 2006-03-18
fusing the negative
"If the unlikely happened and the factory negative battery terminal to chassis ground cable was disconnected, then your radio install would serve as the ground connection.
Think about it... your negative lead on your radio's power cord is connected to the negative battery terminal."
No, I never hook the negative lead up to battery minus directly. I always connect the radio negative lead to the point where the battery negative terminal connects to the chassis. This avoids that issue all-together. Should the battery negative to chassis connection fail, then there is NO DC connection to the battery at all, for the radio.
Posted by
K7AAT on 2006-03-16
What's all the fuse about?
My FT-7800 came with both leads fused so I went with it. I ran 8AWG wire directly from the battery terminals to the engine side of the firewall and connected the fused leads there. The radio sees a healthy voltage which is free from noise.
Posted by
KC2OGR on 2006-03-15
No Point In Fusing Negative Lead
Most radio equipment chassis are considered a direct path to negative polarity.
So when mounting a radio in a car directly to a vehicle's frame under the dash, what purpose does fusing the negative lead do, when negative power is supplied through the vehicle chassis directly to the radio chassis?
In most cases you can completely remove the fuse and the radio will "still" continue to operate because the radio chassis or antenna connector is conducting negative polartity to power the radio.
With so many routes providing a direct path to negative polarity in any given vehicle, you would have to completely isolate the radio equipment (including the antenna ground) from the vehicle chassis before the idea of placing a fuse on the negative power lead would be considered an effective method of protection.
I will continue to fuse the "positive" lead in my mobile installations.
Posted by
KC8VWM on 2006-03-14
There was a great article in QST several years ago about the proper way to install a mobile power connection. I believe the author suggested always fusing both the positive and negative power leads for safety reasons, and to install the fuses as close to the battery terminals as possible. The theory behind this is that if one of the power cables ever develops a short, the fuse will blow, thus preventing the battery from "boiling" and creating a possible vehicle fire or other electrical hazard. I personally always connect directly to the vehicle battery whenever I run a mobile setup, and I use 20 Amp blade type fuses. I would rather be safe than sorry.
73,
KU4UV
Posted by
KU4UV on 2006-03-14
This topic brings up some great points gang. Always remove any kind of rings or other jewelry from your hand before working near a battery or anything else on a car. On one of the TV shows recently where some guys were working on a car, they forgot to disconnect the battery. They touched a positive connection to the car chassis, and sparks flew. I have done the same thing before when working on a starter and forgetting to disconnect the positive battery terminal. I now have a socket wrench with a nice burn mark in it as a reminder to always disconnect the battery whenever working on a car. You would think I should have known better. Stay safe gang!
73,
KU4UV
Posted by
KU4UV on 2006-03-14
What if you're using a Rigrunner?
For what it's worth, I fuse both just to feel better. But I have a question for everyone here.
I know that the "best" way is to wire the radio's power leads directly to the battery. However, in my latest installation I wired my Rigrunner power distribution panel directly to the battery, and I've connected the radios to the rigrunner using Anderson Powerpoles. I don't hear any excess noise, and to date have had no problems with the installation.
Any comments?
Thanks & 73,
Ken N2OBY
Posted by
N2OBY on 2006-03-14
KC8VWM: "So when mounting a radio in a car directly to a vehicle's frame under the dash, what purpose does fusing the negative lead do, when negative power is supplied through the vehicle chassis directly to the radio chassis?"
It prevents damage to the radio harness if the ground straps to the car body or the engine are disconnected, which would make the negative lead from the radio the easiest path for the negative connection from every other electrical device in the car--including the starter.
BTW, if your antenna is properly mounted, there is no way to totally isolate the radio chassis from the ground.
Posted by
K1CJS on 2006-03-14
Ground is not an option
I have installed 100's of radios in my life, having been a 2-way dealer & always known to have the talent to install things.
Once the radio's case is in a mounting bracket (AND bracket is mounted to chassis metal), what is the point?
I have also never seen a ground fuse blow in those 100's of service calls. What is the point again?
Shortest practical ground, direct to chassis, period. I also favor a direct (+) to battery, fused at both ends. That lighter/fusebox tap is the single biggest risk for spikes passed to equipment.
Posted by
K4RAF on 2006-03-14
its con-fuse-ing
I usually run a pos fuse, and seldom add a neg unless it is already there, I also ground the neg battery post to tge chassis, and the engine to the chassis with substantial braid, and I groung the radio and the antenna. ( and the exhaust and the doors etc.)
never had a problem using the neg side of the radio for ground. you probably should check your battery terminals once in a while...! its called maintenance
Posted by
N6AJR on 2006-03-14
Negative Lead Fusing
The way things used to be done was that the negative lead was grounded near the rig. However, because it was short and direct to the chassis, it occasionally shared paths with other sources of noise and was subject to becomming erratic if the ground didn't have a high degree of integrity. By running a negative lead all the way to the battery, the only noise that could be developed in the radio, other than ignition noise, was across the internal capacitance of the battery. Lose the battery to engine or battery to chassis/frame ground and if the radio or antenna were grounded, the negative lead to the battery would go up in smoke quickly when drawing starter current thru it. Wise to fuse it or you may try grounding near the radio, without a fuse. Your choice.
Posted by
WA4DOU on 2006-03-13
As was said, just do it. The time spent doing this is well worth the value of your radio.
Posted by
K8NWX on 2006-03-12
fusing
Just bought a Yaesu FT-857 the power cord is fused on both leads, My FT-847 That is several years old came the same way. THINK the factory was telling me something.
Posted by
W6GMT on 2006-03-12
fusing the negative
So far everyone fo my radios came with the negative fused so i left it that way when i put it in my truck.
Posted by
KI4LIF on 2006-03-12
fuse it good !
i've always fuse mine to the battery,when it blows up front not the radio !
73
Jackie
KG4ORX
Posted by
N4MJG on 2006-03-12
fusing the negative
Friends don't let friends fuse the ground.
Posted by
N2VPC on 2006-03-12
Negative lead fuse
Quote
"The reason for this practice is to assure that if the battery loses its ground connection in the engine compartment, it won't draw starter current (can be 300 amps)thru the negative lead, assuming the radio is grounded or thru a combination of the negative lead and the coax shield (also assuming the antenna shield is grounded at the antenna). "
I drew a schematic and I still don't understand the issue. If the negative lead gets disconnected then nothing will work in the car. Everything is referenced to the car chasis. Atleast this was true 10 years ago. The negative lead from the battery, atleast in my car, a Mustang, is about 6 inches long and goes from the battery directly to the chasis. If it would break then no current could flow to any subsystem in my car! Please explaine how my two meter radio could try to carry this starting current in this senario.
Now in thinking some more I can see where if I connected my rig to the battery terminals and also had my rig connected to the dash board (i.e. chasis grnd) then in the unlikely chance the battery cable broke my subsystem would then draw the starting current.
Well now that explains it, however, I need not worry because I have connected my negative (radio lead) to the chasis.
In my opinon then I guess it would be best to connect a radio to the chasis for a negative ground.
Best regards
W1QWT
Posted by
W1QWT on 2006-03-12
Negative lead fuse
Quote
"The reason for this practice is to assure that if the battery loses its ground connection in the engine compartment, it won't draw starter current (can be 300 amps)thru the negative lead, assuming the radio is grounded or thru a combination of the negative lead and the coax shield (also assuming the antenna shield is grounded at the antenna). "
I drew a schematic and I still don't understand the issue. If the negative lead gets disconnected then nothing will work in the car. Everything is referenced to the car chasis. Atleast this was true 10 years ago. The negative lead from the battery, atleast in my car, a Mustang, is about 6 inches long and goes from the battery directly to the chasis. If it would break then no current could flow to any subsystem in my car! Please explaine how my two meter radio could try to carry this starting current in this senario.
Now in thinking some more I can see where if I connected my rig to the battery terminals and also had my rig connected to the dash board (i.e. chasis grnd) then in the unlikely chance the battery cable broke my subsystem would then draw the starting current.
Well now that explains it, however, I need not worry because I have connected my negative (radio lead) to the chasis.
In my opinon then I guess it would be best to connect a radio to the chasis for a negative ground.
Best regards
W1QWT
Posted by
W1QWT on 2006-03-12
Cheap Insurance
A car battery can be a real nasty device. An old mechanic once put an adjustable wrench accidentally across the terminals of a car battery. He had his gold wedding band on that hand. He is lucky to still have his hand today, although it doesn't function very well. The wrench glowed a dull orange, and the ring? Well, he has one heck of a scar where that used to be. What has this got to do with a fuse in the negative lead? Well let's just say it's got to do with a little more peace of mind. Respect that lead acid battery!
Posted by
AI2IA on 2006-03-12
"I drew a schematic and I still don't understand the issue. If the negative lead gets disconnected then nothing will work in the car. Everything is referenced to the car chasis."
If the unlikely happened and the factory negative battery terminal to chassis ground cable was disconnected, then your radio install would serve as the ground connection.
Think about it... your negative lead on your radio's power cord is connected to the negative battery terminal. This negative lead has continuity with the chassis of your radio and the negative antenna contact. If your antenna mount is grounded to the vehicle (which it should be)... or if you've grounded the chassis of your radio to the chassis of the vehicle... then your radio install would essentially complete the ground circuit if the factory ground cable failed. The ground would go from the batteries negative terminal to the radio's power cord to the chassis of the radio to the negative lead of the antenna to the chassis of the vehicle. Even if nothing happened to the inside of the radio, the ground of the radio's power cord and the antenna mount are not designed to handle nearly the amount of current the starter would need to start the car.
I'd suspect this is the very reason why most car stereo amplifier installation kits don't have a fused negative lead - since the ground lead is typically only a couple feet long and connected to the closest chassis point instead of the battery, it will not "complete the ground circuit" in the event of a factory ground cable failure.
Really, with a fuse and fuse holder only running a few bucks you'd be silly not to throw it in line with your ground just for the peace of mind it brings.
73,
Dan / ab0re
Posted by
AB0RE on 2006-03-12
fusing the negative
That depends on the age of the radio, if the radio is old enough to where the ground comes from the case of the radio, the the red lead or the positive lead is obvious, however the newer radio that are grounded through the wire, then fusing the ground and positive wires are good then, and both leads always taken to the battery or the post closest to the battery to avoid corrosion of the lead,by running the leads directly to the battery, you can possible eliminate spark plug noise and or alternator whine coming into the radio,if not maybe extra filtering may be necessary, or the batteries natural filtering capability may be gone and time to replace the battery... in either case taking the power leads directly to the battery is usually the best.....73 Mark w6mrk
Posted by
W6MRK on 2006-03-11
Just Do IT
I won't get into the arguments pro or con - I figure that it can't hurt so, I always do it.
Posted by
KG4RUL on 2006-03-11
Fusing the Negative
Don't newer radios (in the past 30 years) have the cable ground connect internally to the chassis? (a screw connecting a wire or circuit board to the chassis)?
I think that in the majority of cases, you would want to the fuse on the high-potential side to blow out first.
It might be different if you have a "floating" chassis, but you still haven't removed the high-potential side if the negative blows out first. You can still get a secondary spark.
Doesn't NFPA or some other organization cover this issue?
John
N1ERF
Posted by
N1ERF on 2006-03-11
A fuse in negative lead, Why?
Usually the same current flows in both the positive lead and the return. I mean where else can it go in a car?
Also almost all the cars I know have the battery grounded right there at the battery and the radio is grounded not only through the mount but also at the antenna mount. Why back some 20 years ago nobody provided a ground in both leads! Maybe it is just because of litigation? Like too hot coffee?
I don't know but I wish somebody out there could explain it to me. Do they float the supplies in mobile rigs now?
Thanks
and best regards
W1QWT
Posted by
W1QWT on 2006-03-11
A fuse in negative lead, Why?
Usually the same current flows in both the positive lead and the return. I mean where else can it go in a car?
Also almost all the cars I know have the battery grounded right there at the battery and the radio is grounded not only through the mount but also at the antenna mount. Why back some 20 years ago nobody provided a ground in both leads! Maybe it is just because of litigation? Like too hot coffee?
I don't know but I wish somebody out there could explain it to me. Do they float the supplies in mobile rigs now?
Thanks
and best regards
W1QWT
Posted by
W1QWT on 2006-03-11
A fuse in negative lead, Why?
Usually the same current flows in both the positive lead and the return. I mean where else can it go in a car?
Also almost all the cars I know have the battery grounded right there at the battery and the radio is grounded not only through the mount but also at the antenna mount. Why back some 20 years ago nobody provided a ground in both leads! Maybe it is just because of litigation? Like too hot coffee?
I don't know but I wish somebody out there could explain it to me. Do they float the supplies in mobile rigs now?
Thanks
and best regards
W1QWT
Posted by
W1QWT on 2006-03-11
fusing the negative
Well this is what i know if you by a new mobile rig the wiring comes all reddy fused
on positive and ground ! As for an old rig ho knows? But most where case grounded !
Posted by
KG4WZC on 2006-03-11
Fusing the negative
The reason for this practice is to assure that if the battery loses its ground connection in the engine compartment, it won't draw starter current (can be 300 amps)thru the negative lead, assuming the radio is grounded or thru a combination of the negative lead and the coax shield (also assuming the antenna shield is grounded at the antenna).
Posted by
CURMUDGEON on 2006-03-11