| Author |
Message |
    
Tech808
Moderator
Username: Tech808
Post Number: 12251
Registered: 8-2002
| | Posted on Tuesday, November 14, 2006 - 12:44 pm: | 
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Below are some helpful articles on Properly Grounding your Radio Station.
Copper Talk
» Subscriber (Preview)
» Product Reviews » Polyphaser -
Lightning Arrestor
» Discussion of Polyphaser Review
Copper Talk
» Subscriber (Preview)
» Product Reviews » Polyphaser -
Lightning Arrestor » Review
Copper Talk
» Subscriber (Preview)
» Articles
» Protect your equipment
from Lightning
Copper Talk
» Subscriber (Preview)
» Articles
» Antenna Grounding
Hope this help's,
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Tech833
Moderator
Username: Tech833
Post Number: 1511
Registered: 8-2002
| | Posted on Wednesday, November 15, 2006 - 12:30 am: |
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Can you make any of those links 'clickable' to make it easier for people to find them? |
Tech808
Moderator
Username: Tech808
Post Number: 12257
Registered: 8-2002
| | Posted on Wednesday, November 15, 2006 - 7:09 pm: |
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Sorry,
I just used the SEARCH feature located under: Utilities to the LEFT of the Forum here and copied and pasted the links below for everyone.
JUST CLICK on the LINKS Below.
Polyphaser - Lightning Arrestor » Review
Discussion of Polyphaser Review
Antenna Grounding
Hope this help's,
Lon
Tech808
CEF808
N9CEF
CVC#2 |
Penrider
Junior Member
Username: Penrider
Post Number: 26
Registered: 1-2007
| | Posted on Friday, February 16, 2007 - 8:18 pm: |
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for tech833.....my new base(magnum s3200b) will be in my upstairs office, no choice that's where such things have to go...it'll be approx. 20ft worth of ground wire from my rig(antenna is already properly grounded with lightning arrestor, etc.)..I can't get my rig ground wire any shorter than that...anything else I can do, or just keep swr low and run with it?
Sean
CEF867
CVC81
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Tech833
Moderator
Username: Tech833
Post Number: 1606
Registered: 8-2002
| | Posted on Saturday, February 17, 2007 - 9:31 am: |
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Sounds O.K. to me. |
Penrider
Junior Member
Username: Penrider
Post Number: 27
Registered: 1-2007
| | Posted on Saturday, February 17, 2007 - 7:57 pm: |
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thank you sir
Sean
CEF867
CVC81
|
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2399
Registered: 9-2004
| | Posted on Sunday, February 18, 2007 - 1:07 am: |
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paul, i believe the reason he is asking is because most of us on here are of the belief that the ground wire going from your radio to a ground rod needs to be shorter than 1/4 wavelength at the freq. of operation (approx. 102" for 27mhz), or it could act like an antenna causing TVI and other dangerous problems related to ground potential.
i myself have adhered to this thinking and would be very interested to know if its only certain lengths that need to be avoided, and maybe certain lengths that will not present a problem.
thanks for any clarification you can lend to this.
i think lots of us could learn something here.
matt |
Tech833
Moderator
Username: Tech833
Post Number: 1607
Registered: 8-2002
| | Posted on Sunday, February 18, 2007 - 11:44 am: |
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I don't know who ever said a ground wire has to be this length or that. The shorter, the better. Although, a 50 foot ground lead is still better than none.
By the way, grounding to the steel structure of a high-rise building is just as acceptable as agrounding to a good ground rod at floor level. Assuming that steel you are bonding to is also bonded to the foundation. So, if this is true, then why wouldn't running 20 feet of good wire from your rig to the ground also be acceptable?
Sometimes, the CB folklore gives me a big chuckle. 1/4 wave ground leads and such! Ha ha ha!!
The exception is ground wires buried under ground used as radials. Then, 1/4 wave wires would be the minimum effective length. Above ground, the rule is 'short as possible'. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3508
Registered: 7-2004
| | Posted on Sunday, February 18, 2007 - 7:09 pm: |
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paul, to dig deeper into matt's question, & your reply citing cb folklore....the FCC general exam i just took has a question, G4C05-if your 3rd floor amateur station has a ground wire running 33 feet down to a ground rod, why might you get an RF burn if you touch the front panel of your HF transceiver? and the correct answer is because the ground wire is a resonant length on several HF bands and acts more like an antenna then an RF ground connection.
reading the 'classwork' in the arrl general class license manual, chapter 4 states .....an effective station ground connection should be short; not more then a few feet in length. if your ground connection is a resonant length at your operating frequency, it will act more like an antenna then an rf ground connection...... unfortunately, the manual does not delve further into a solution. while 'approx 20 feet' is not a half wave on 27 mHz, i suppose where the connections are made & just how close to 'approx 20 feet' COULD cause it to be resonant on 27 mHz. if that was the case, then how would you resolve the situation? change the routing of the ground wire? change the hookup location on the ground rod, as well as equipment? use a LONGER ground wire, maybe 27-30' so it has less of a chance of being resonant on 27 mHz?
yeah, there are plenty of cb, & amateur 'folklores' floating around, but, it seems the FCC could be contributing to this one. in regards to the FCC's wording on the subject, are they WRONG, or just incompletely defining the answer? |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2402
Registered: 9-2004
| | Posted on Sunday, February 18, 2007 - 9:42 pm: |
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thank you pat.
c'mon paul; you know what im asking.
i remember this stuff from when i took my ham test in 1989.
unless i have been misinformed by the literature that ive read; this IS a valid concern, and if we dont address it as such then we are the ones supporting CB folklore.
we need a ruling here, and you be da man.LOL
matt |
Tech833
Moderator
Username: Tech833
Post Number: 1608
Registered: 8-2002
| | Posted on Monday, February 19, 2007 - 9:27 am: |
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The exam isn't exactly 'wrong', they just took a very remote possibility and exploited it. You have about the same chances getting zapped from your grounded radio as you do having your cell phone burst into flames in your pocket (one in a zillion). BUT, however slim it may be, the chance exists, so they print it.
An exact resonant length of ground wire *might* act as an antenna, and at extremely high power levels with the EXACT amount of resistance at the ground rod, *might* end up with its voltage node at the radio chassis itself, and *might* be at enough potential to provide the sweaty skinned user a small zap. Like I said, one in a zillion. However, this is a safety ground, not RF ground I am talking about. There is no 'resonant length' for DC. This possibility does not apply to this situation.
I have tried to duplicate this in the lab many times, and I have to be honest, it is nearly impossible to do without a tuned circuit in the ground lead to get the tuning exact enough to duplicate it. And, it takes power levels way beyond the CB limits. That is why I chalked this one up to CB folklore.
If this were a broadcast forum, it would be a consieration. Since this is a CB forum, and PEP is limited to 12 watts, and this question referred to a safety ground, it does not apply. Those running more power are assumed to be knowledgeable enough to weigh the possibilities. Those running illegal power on CB without knowledge are not my concern. Shame on you. |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1463
Registered: 6-2004
| | Posted on Monday, February 19, 2007 - 10:06 am: |
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That is a situation where an artificial ground would be beneficial. Even a simple 1/4 wavelength wire attached to the transceiver would help to prevent RF bite if you use the same frequency all of the time.
Artificial grounds do have their use.
Aack! - Bill the cat
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Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2405
Registered: 9-2004
| | Posted on Monday, February 19, 2007 - 7:43 pm: |
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well i have always considered this to be much more than a CB forum. after all, how many CB'ers has this forum alone influenced to get their ham license? lots.
all these new hams want to get the most from their setups, and dont want to perepuate any myths along the way.
so, lets use a hypthetical situation:
assume i am an extra class ham running 1500 watts PEP on the section of 10 meters that i am allowed to.
my station is on the second floor, so the ground wire going from my radio equip. to a ground rod is 17 feet long.
in terms of RF grounding; have i created any possible problems?
should i be conserned?
i know it sounds as if i am ingnoring your post and asking the same question a different way, but because this is such a misunderstood facet of grounding to many of us, i believe that it warrants a thourough discussion.
"Those running more power are assumed to be knowledgeable enough to weigh the possibilities."
paul, YOU are one of the sources of this knowledge. please do not assume that you are condoning bad CB behavior, but rather that you are helping create the best informed group of new hams that will further perpetuate good operating principles.
dont get me wrong, im sure we all truely appreciate your time and effort, and just like in school; one intelligent statement by the teacher creates 1,000 stupid questions from the class.
matt |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2406
Registered: 9-2004
| | Posted on Monday, February 19, 2007 - 11:25 pm: |
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well, i thought i would do my part to try and understand this stuff better; so i went a'lookin' and found this from the ARRL:
c. RF ground. This is required only for certain types of antennas-- ones which require current flow to ground to complete the antenna circuit. An example is a quarter-wave vertical. One wire of the feedline connects to the base of the antenna, and the other connects to ground. The connection to ground has to have a low RF resistance, or you'll expend too much of your power heating the ground. A few radial wires will provide a moderately low loss connection. A ground rod will help a little, but the RF resistance will be high, resulting in quite a bit of loss. Chapter 8 of the ARRL Antenna Book shows the approximate trade between resistance and number of radials. If your antenna is much shorter than ¼ wavelength, you'll need many, many radials to get reasonable efficiency. If it's longer, you can get by with fewer. A ½ wavelength base-fed vertical needs only a very modest ground, and a ground rod is adequate. The requirements for various other end-fed antennas depend on their length. If you use a "complete" antenna like a dipole or a ground plane (that is, one that doesn't require your feedline to connect to ground), you don't need a RF ground, as long as you keep common-mode currents off your feedline. A "current" or "choke" balun is most commonly used for this.
i think this clears up a lot for me, what do you think 833?
matt |
Penrider
Junior Member
Username: Penrider
Post Number: 28
Registered: 1-2007
| | Posted on Tuesday, February 20, 2007 - 1:39 am: |
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kid and pat..y'all hit on exactly why I was asking..I just wanted to ask paul if there was really anything else I could possibly do...I Am after a good Safety ground, not rf...all my equip will be to a bus bar, then straight out the wall about 4ft, then straight to the ground approx 15ft to a ground rod which will also be attached to my house electrical ground rod...I couldn't think of a better ground, so I put the question out there....y'all got a good topic going and answered some good questions...and Paul, just in the short time I've been reading the forum, your posts have answered a number of questions for me already...Thanks
Sean
CEF867
CVC81
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Tech833
Moderator
Username: Tech833
Post Number: 1609
Registered: 8-2002
| | Posted on Tuesday, February 20, 2007 - 10:21 am: |
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Sean, You're welcome. I learn a lot here too.
KV, I wish it were that simple. The ARRL blurb has about 3 things in it that are incorrect.
The ARRL paragraph is only assuming you want a low SWR, and some ground coupling as a little concern side benefit. The fact is, RF ground is vital to antenna performance and low receiver noise. I cannot overstate the importance of it. A safety ground is vital to living a long life. Two separate things to consider.
Moving to a 1/2 wave requiring fewer radials is only true for SWR considerations. The fact is, the 1/2 wave antenna takeoff angle will increase greatly as you reduce the radials (ground coupling). Remember, an antenna is nothing but a transducer. The antenna system has to couple RF current to the sky and ground. Unless you get up into the UHF range, ground is ALWAYS a major consideration in the equation. Blowing off the RF ground the way the ARRL antenna book does is leading people to a poor performing system.
Ground heating is caused by stray currents around the antenna base that are ineffectively coupled. We call them 'heat loss' or 'ground loss'. You need to get that current working for you. The only way I know to do that is with the use of adequate RF ground. Even a 1/2 wave will lose a bunch of current into the dirt if you do not have adequate RF ground, there is no exception. Raising the antenna above ground reduces this also, but not nearly as much as extensive radials. Unless you get the antenna many, many wavelengths above ground, the radials will always give the most bang for the buck (so to speak). A ground rod alone is NOT adequate! No broadcast literature will agree with the ham literature description.
It is frustrating to fight the uphill battle refuting the ham publications. I can tell you this, no professional engineer designing/building broadcast and shortwave transmission facilities refers to the ARRL publications for help. However, for the rank beginner simply trying to get a ham station on the air, it is better than nothing. It is NOT the gospel, it is a preschool of sorts. I'll bet your high school instructors disputed things you were taught in kindergarten, right? Even your parents told you that there WAS a Santa Claus, but you later found out that even your parents can be wrong. Same situation here. I am telling you, the ARRL is wrong. |
Airplane1
Advanced Member
Username: Airplane1
Post Number: 968
Registered: 5-2004
| | Posted on Tuesday, February 20, 2007 - 2:15 pm: |
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WHOOOOOOO! I thought I was confused before, now I realy am.
Roger |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2410
Registered: 9-2004
| | Posted on Wednesday, February 21, 2007 - 1:24 am: |
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i have no problem with that paul.
i imagine the ARRL has to take the beginners into account.
so i think i am starting to understand something here.
somewhere along the way in our extensive grounding discussions, the less than 8.5 feet from radio to ground rod thing got called, "RF ground", which it is not. it is a safety ground that might possibly act as an antenna if certain conditions are met, however remote the possibility.
the reason we are confused is that we have all been calling that wire our RF ground, when it is nothing more than a safety ground wire with a few considerations to be taken into account.
namely that certain lengths could cause a problem under the right circumstances.
the RF ground you are referring to is the system of horizontal radial wires run underground at the base of the antenna to increase ground coupling.
and both kinds of grounds are imperative for the best possible performance.
right?
so, if im not too confused here, then the ground wire going from the station equipment to ground can be any convenient length?
should we 11meter ops. try to stay away from 8.5 feet and 17 feet?
should we even give it a second thought?
now about the RF ground:
for all of us that have an antron 99 up at 36-40 feet to the feedpoint, with a mast running down to the ground could benefit from a series of radial wires extending horizontally from the base of the mast? (1 wavelength min.)
this is true until you get more than approx. 340 feet or more into the air at the feedpoint?
is this true for all popular CB antennas?
one last question:
how much performance are we talking about here.
would it be the difference between hearing skip on a given day and not hearning any?
or are we talking a quieter receiver, and the TX signal gets out a bit further?
thanks for all you do paul; im sure we are frustrating.
i think im finally getting a handle on this!
matt |
Airplane1
Advanced Member
Username: Airplane1
Post Number: 969
Registered: 5-2004
| | Posted on Wednesday, February 21, 2007 - 6:29 am: |
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Kid_vicious, Those are the same questions I came up with and think I understand this is the answers are yes to those questions.
I have one more to add, Does a antenna with a ground plane not need radials placed in the ground like a A99 or vertical without groundplanes?
Thanks Paul for helping us out,
Roger |
Tech833
Moderator
Username: Tech833
Post Number: 1612
Registered: 8-2002
| | Posted on Wednesday, February 21, 2007 - 10:52 am: |
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KV, you're really starting to get this!! Good job!
"the RF ground you are referring to is the system of horizontal radial wires run underground at the base of the antenna to increase ground coupling.
and both kinds of grounds are imperative for the best possible performance.
right?"
The RF ground is for performance (lowering the antenna takeoff angle). The safety ground is to keep your gear from zapping you. The lightning ground is to keep lightning from entering your shack. Confused yet?
"so, if im not too confused here, then the ground wire going from the station equipment to ground can be any convenient length? "
The shorter, the better.
"should we 11meter ops. try to stay away from 8.5 feet and 17 feet?
should we even give it a second thought? "
No, no.
"for all of us that have an antron 99 up at 36-40 feet to the feedpoint, with a mast running down to the ground could benefit from a series of radial wires extending horizontally from the base of the mast? (1 wavelength min.)"
Yes. Although, the closer the antenna is to ground level, the more pronounced the benefit will be. 1 wavelength radials won't do much more than 1/4 wave long radials. But, the more ground coupling you have the better it is, so I always suggest using longer radials if you have the space to do it.
"this is true until you get more than approx. 340 feet or more into the air at the feedpoint?"
The higher the antenna above ground level, the less the radials will help.
"is this true for all popular CB antennas?"
All bottom fed antennas (A99, Imax, V-5/8, ground plane, etc.). This does not pertain to antennas like the Top One or the Penetrator R/S.
"how much performance are we talking about here.
would it be the difference between hearing skip on a given day and not hearning any?
or are we talking a quieter receiver, and the TX signal gets out a bit further? "
It is lowering your takeoff angle. It probably won't make much difference on 'skip', but will add tremendous gain for your ground wave contacts (non skip). The takeoff angle difference on an Imax 2000 at 15 feet to the feedpoint is like 5 dB or more depending on your ground conductivity! That is about 1 more S-unit!! Some 1/2 wave antennas like the A99 will benefit even more.
"I have one more to add, Does a antenna with a ground plane not need radials placed in the ground like a A99 or vertical without groundplanes? "
We are not talking about ground planes, we are talking about ground conduction. Two completely different things. Ground planes help with SWR by affecting feedpoint resistance. In some cases (like on a 5/8 wave antenna) they are essential to making the antenna match the coax. They also do help lower takeoff angle by balancing the base currents on the antenna. For a visual explanation of this, see the Imax 2000 GPK review. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2416
Registered: 9-2004
| | Posted on Saturday, February 24, 2007 - 9:00 pm: |
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well there you have it folks!
difinitive answers to some long misundrstood concepts.
one day i sure would like to have a yard big enough to finally do it right.LOL
we all very much appreciate your time and efforts paul.
hey, didnt we have this whole thing figured out months ago? LOL!
matt |
Airplane1
Advanced Member
Username: Airplane1
Post Number: 971
Registered: 5-2004
| | Posted on Monday, February 26, 2007 - 8:22 am: |
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Thanks a bunch 833 |
Tech833
Moderator
Username: Tech833
Post Number: 1613
Registered: 8-2002
| | Posted on Monday, February 26, 2007 - 9:29 am: |
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Think nothing of it, KV. Yes, we covered this a few months ago. Never hurts to refresh the memory. |
Wildrat
Senior Member
Username: Wildrat
Post Number: 1252
Registered: 12-2003
| | Posted on Wednesday, February 28, 2007 - 2:37 pm: |
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Sounds Like someone needs to get the shovel out and dig a little more.
WILDRAT
MARK
27.285MHZ
CEF674
CVC029
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Unit199
Intermediate Member
Username: Unit199
Post Number: 440
Registered: 8-2003
| | Posted on Wednesday, February 28, 2007 - 10:39 pm: |
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How many times is Tech833 going to have to explain about grounding radio set-ups???? I feel this subject is being run in the ground. He has more than explained it in many posts to where it should be understood by now.
HARVE
UNIT199
CEF210
CVC18
KB0YVK
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Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2433
Registered: 9-2004
| | Posted on Thursday, March 01, 2007 - 12:31 am: |
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"run into the ground" that was funny!
harve, i personally needed to learn something here, as i thought i had it figured out, but the 8 foot ground wire from the station thing threw me.
it threw lots of others too, as can be attested to in the members pictures area.
paul will probably have to explain this concept as many times as you have had to explain SWR to a new guy.LOL (im sure its more than a few!)
matt |
Wildrat
Senior Member
Username: Wildrat
Post Number: 1258
Registered: 12-2003
| | Posted on Thursday, March 01, 2007 - 8:44 am: |
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10-4, if he doesn't mind I don't mind. I always learn something reading 833's post. I'm glad he's here to help. A lot of new people come here and they are not familiar with the site and miss the search function, I even forget about it sometimes till 808 says something about it. This entire site if you look at is repetition of questions....
WILDRAT
MARK
27.285MHZ
CEF674
CVC029
|
Tech833
Moderator
Username: Tech833
Post Number: 1616
Registered: 8-2002
| | Posted on Thursday, March 01, 2007 - 10:16 am: |
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I just thought I was developing an old-age memory loss problem. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3520
Registered: 7-2004
| | Posted on Friday, March 02, 2007 - 5:09 pm: |
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'grounding'....'run in the ground'-you're a FUNNY guy harve  .
actually, i think penriders question WAS a bit different, requiring some clarification on why an answer was....what it was.
as for some other subjects, harve, you may be right! |
Unit199
Intermediate Member
Username: Unit199
Post Number: 442
Registered: 8-2003
| | Posted on Friday, March 02, 2007 - 7:22 pm: |
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If antenna is grounded, how long is the ground wire??? Need I say more???
HARVE
UNIT199
CEF210
CVC18
KB0YVK
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Sniper
Member
Username: Sniper
Post Number: 53
Registered: 5-2006
| | Posted on Saturday, March 03, 2007 - 6:29 pm: |
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IS THERE ANY ADVANTAGE TO HAVING YOUR ANTENNA MAST ACTUALLY BURRIED 3 FEET IN THE GROUND??MINE IS AND I GET ALMOST NO STATIC/RF AT ALL.sniper... |
Penrider
Junior Member
Username: Penrider
Post Number: 37
Registered: 1-2007
| | Posted on Saturday, March 03, 2007 - 9:58 pm: |
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unit199...why didn't I think of that???
Sean
CEF867
CVC81
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Road_warrior
Senior Member
Username: Road_warrior
Post Number: 2076
Registered: 7-2004
| | Posted on Monday, April 16, 2007 - 9:37 pm: |
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Great thread! Some of you know i've been having
neighbor problems and i can use all the info
and refreshing i can get...lol
----------------------------------------
RoadWarrior
Cef 375 Pa |
