Finally after the big thaw I got a chance to go outside this week and work on my HF antennas. For the first time in years I set up my Yaesu receivers and have them hooked up to various long wire and dipole antennas. I wanted to set up a ground line in the yard so I took about 30 feet of copper wire and attached in to a rod approximately 30 inches into the ground. The rod is made of brass (not copper). After connecting the ground to my radio I checked out the signal of several bands. I don't notice any change in signal quality or noise level whether the line is attached or not. Am I doing something wrong? I see on some youtube videos a huge boost in performance with a proper ground.
Ground Wire Mistakes?
- Thread starter SatHunter
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I've never seen any noise reduction from grounding an antenna and I have seen noise increase when grounding an antenna. The latter would be from noise or RFI making devices in your house all sharing a common ground that you now connected to your antenna and invited the noise in. Noise doesn't know to travel to ground, it just doesn't know any better. Many antennas do not require any earth ground in relation to performance except maybe a vertical antenna in the yard which might require ground radials or a ground screen to lower ground resistance and improve radiation pattern. That's a different use of a ground.
The National Electrical Code has requirements for antenna grounding and you can search "NEC article 810" to find those specifics. These have nothing to do with noise reduction and will do little to help with a direct lightning hit, the NEC is more for human safety preventing differences in potential that can become an electrical hazard.
With that, any ground rods you add must be bonded to the main house electrical ground with no less that 6ga copper wire and depending on length that may need to be upgraded. A 4ft ground rod does not meet any code that I know of and is usually not that useful, you need 8 to 10ft of ground rod to be at a minimal level of effectiveness.
The National Electrical Code has requirements for antenna grounding and you can search "NEC article 810" to find those specifics. These have nothing to do with noise reduction and will do little to help with a direct lightning hit, the NEC is more for human safety preventing differences in potential that can become an electrical hazard.
With that, any ground rods you add must be bonded to the main house electrical ground with no less that 6ga copper wire and depending on length that may need to be upgraded. A 4ft ground rod does not meet any code that I know of and is usually not that useful, you need 8 to 10ft of ground rod to be at a minimal level of effectiveness.
Grounding an antenna system is done mainly for lightning protection.
At HF you will not likely notice much if any change by grounding the radio as you describe.
Ground wave reception at LW and MW may be enhanced by adding an earth ground.
You mentioned long wire and dipole antennas, a vertical antenna is a different matter and needs
ground radials.
For a good reference on how to ground, see the ARRL Grounding and Bonding for the Radio Amateur
by H. Ward Silver.
At HF you will not likely notice much if any change by grounding the radio as you describe.
Ground wave reception at LW and MW may be enhanced by adding an earth ground.
You mentioned long wire and dipole antennas, a vertical antenna is a different matter and needs
ground radials.
For a good reference on how to ground, see the ARRL Grounding and Bonding for the Radio Amateur
by H. Ward Silver.
This is what I always understood being in the hobby since I was 5 years old & with my father being a mentor & very active in the hobby. What caught my curiosity was a video I watched this week that shows a big improvement in the signal quality on a SDR system by adding a ground. I'm not sure if it's OK to post a link. If not please let me know & I'll delete it. Please comment after watching the video.
Interesting video, it proves that experimenting with an antenna can produce improved reception.
Otherwise, for me anyway, the video provides more questions than answers.
Gotta wonder if the signal from Northern Germany on 6085 at midday was NVIS or did it have a groundwave
component to it? The station was perhaps only 300 or so miles away so groundwave is a possibility...
especially since driving a ground rod improved reception and then reception was improved even more when he
improved ground conductivity by adding the water.
It also would have been interesting if he had raised the counterpoise off of the ground and got it up in the air
thus creating a typical half-wave dipole and seeing what affect it had on the signal strength.
The abundance of signals seen on the 22 meter band at midday really didn't prove anything... a random length of wire
shoved into the SO-239 would probably have produced the same result.
A SWL can read about and talk about antenna theory all day but going out and actually experimenting with the antenna
will in the end give the best results.
Otherwise, for me anyway, the video provides more questions than answers.
Gotta wonder if the signal from Northern Germany on 6085 at midday was NVIS or did it have a groundwave
component to it? The station was perhaps only 300 or so miles away so groundwave is a possibility...
especially since driving a ground rod improved reception and then reception was improved even more when he
improved ground conductivity by adding the water.
It also would have been interesting if he had raised the counterpoise off of the ground and got it up in the air
thus creating a typical half-wave dipole and seeing what affect it had on the signal strength.
The abundance of signals seen on the 22 meter band at midday really didn't prove anything... a random length of wire
shoved into the SO-239 would probably have produced the same result.
A SWL can read about and talk about antenna theory all day but going out and actually experimenting with the antenna
will in the end give the best results.
I absolutely agree. I thank you for your insights! My main objective is to set up the best antenna system possible while trying to minimize the noise radiating around here. As I anticipated grounding is more of a safety protocol. I have really good signal quality on the 15 - 80m bands when the conditions are right. I'm going to try to experiment with ferrite cores to cut down on the noise as well.
Just an idea, while you're at it (setting up new antennas), check for "snakes in your feedline" which is basically to terminate the feedline before the antenna, and see if you can receive anything using it, you shouldn't be able to. There was an article about it somewhere (I can't find it right now), and the solution was (as far as I can remember) grounding the shield at the antenna feedpoint and halfway along the feedline.
Thanks
Joel
Thanks
Joel
I'll check that out for sure. So am I correct in understanding that a long wire antenna should always be fed into the house and to the receiver with coax cable? I've just been stringing copper wire from the yard right to the radio
Go to the International Radio Club of America (IRCA) website and see free reprint A-151.
Will do. Many thanks!
A receive only "long wire" antenna can be fed into the house with copper wire, it was done that way for years. However, nowadays with all the noise from various electronic devices and appliances a coax feedline is probably better.
You may want to look at the PAR EF-SWL antenna, it comes with a matchbox with a SO-239 connector. Also on the matchbox are some studs that can be used to connect an optional ground or counterpoise if your experimenting shows these to be of an advantage.
The antenna comes with about 45' of wire but you can lengthen it for better performance at lower frequencies if you wish.
If you are considering a permanent outdoor installation remember to provide lightning protection.
Thats the one... thanks for the great set of references also.
Regarding whether you should use coax or some other lead in... it's up to a little debate...
Lankford <SP?> suggests using twin lead or ethernet cable vs. co-ax for rx...
I understand it to a point as being that since a transformer is used (usually) at the radio feed, any spike from noise shows up at the transformer on both sides of it, which means it doesn't get passed, whereas a differential signal does get passed. (This may not be the best explanation, but I tried).
Good luck and keep us up to date on how everything works out ! !
Thanks
Joel
That is a great recommendation and I'll definitely look into it. Before reading this I was actually out in the yard and strung up another 40 ft wire just to experiment. Much to my surprise I gained close to 15dB around 30 meters as compared to my 75 ft antenna strung up on the opposite side of the yard. In fact WWV on 10 mhz almost overloaded from the strong signal on the Sangean. I don't know if it's the conditions today but the noise is insane on every outdoor antenna. I usually hear a lot of contacts on 20m this time of day but today the noise is washing almost everything out.
Thanks Joel! Your explanation makes perfect sense. Making with some tweaking I can set up the "radio shack" I always dreamed of. For years I turned away from the hobby because reception in my area of town seemed almost impossible on the HF bands. Living downtown with a police station close by, lots of electronic advertising signs and a telephone company using microwave and satellite to deliver signals has made me want to move out to the country many times. The new 3 story house built next door is another headache. Certain times of the day there is an intense noise level generated that nothing seems to filter out.
KB2GOM
Active Member
I recently had this experience in experimenting with a ground:
Bottom line: I got a half an S-unit improvement in signal.
Jock gets a good grounding!
Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post: Getting grounded – at last! By Jock Elliott, KB2GOM Readers’ comments are among the best things about writ…
swling.com
Bottom line: I got a half an S-unit improvement in signal.
For HF or SWL reception you have to consider signal to noise ratio is most important and absolute signal level is meaningless in most cases. So you ground your radio or coax and a signal goes up by half an S unit. What happened to the signal to noise ratio? If it got better, great, but did it get worse because connecting to a ground brought up noise and RFI and the increase on your S meter is really showing the noise increase?
In many if not most cases grounding your coax or radio to a grounding point in the house like the third prong of an AC outlet or the house ground rod brings in more noise because that point is common to all other electronic devices in the house that create RFI and noise. Noise doesn't know any better to travel to ground, the ground wires end up being a freeway for the noise to travel around the house distributing the noise to more places.
In many if not most cases grounding your coax or radio to a grounding point in the house like the third prong of an AC outlet or the house ground rod brings in more noise because that point is common to all other electronic devices in the house that create RFI and noise. Noise doesn't know any better to travel to ground, the ground wires end up being a freeway for the noise to travel around the house distributing the noise to more places.
I recently had this experience in experimenting with a ground:
Jock gets a good grounding!
Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post: Getting grounded – at last! By Jock Elliott, KB2GOM Readers’ comments are among the best things about writ…swling.com
Bottom line: I got a half an S-unit improvement in signal.
KB2GOM
Active Member
I used an outside ground rod (just outside the window) and saw one-half S-unit increase in signal with no apparent increase in noise. It's an incremental improvement, I think.
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