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Do you always need a ground when you use an outdoor antenna?
If I run a wire out the window to a tree near the house, do I also need to run a ground wire to the ground outside? Does an outside wire perform better if it's grounded or is it a safety precaution (or both)? Thank you, Jim I would suggest getting a heavy duty lightning arrestor for your antenna and also a " Quick release" antenna mechanism in case of lightning storms; and possibly install a lightning rod in the tree itself.. Lightning is a very bad thing to have happen to your house; I believe even a near miss will fry all electronics in the house.. |
Jim Williams wrote:
If I run a wire out the window to a tree near the house, do I also need to run a ground wire to the ground outside? Does an outside wire perform better if it's grounded or is it a safety precaution (or both)? It's mainly a safety issue, since you can't make a good RF signal ground for the type of antenna you're considering (random wire or inverted-L), *unless* you use the technique on the following website: http://www.anarc.org/naswa/badx/ante...e_antenna.html An RF signal ground needs to be short. Several feet of ground wire is too much. That's why the grounding method on the website (above) works so well. The ground wire to the rod is very short. Mine is about 12-inches. Even if you're not interested in reducing noise with a good RF ground, it's still a good idea to have some kind of ground for lightning or just static electricity. I suggest you install a ground rod near the location where the antenna wire comes inside the house. Connect a lightning arrestor between the antenna lead wire and the rod. Better yet, build the antenna design on the website above. This method helps to reduce noise from domestic appliances such as televisions and computers. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"-=jd=-" wrote in message
... On Tue 20 Apr 2004 10:46:11a, Jim Williams wrote in message : I look at it like this, every situation is different and just because something works like gang-busters for me, doesn't necessarily mean it will for you. However, you won't know unil you try it. -=jd=- I back this statement 100 percent. A different location, a different antenna, different soil conditions, all lead to different circumstances. Experimentation is the proper approach here. Al KA5JGV San Antonio, Tx. |
I'm curious as to how you can have such a short lead to the ground
rod? It's more than 12" from my radios to the window. Doesn't the ground wire connect to the ground connection on the radios? Thanks, Dan On Wed, 21 Apr 2004 02:27:19 -0400, starman wrote: Jim Williams wrote: If I run a wire out the window to a tree near the house, do I also need to run a ground wire to the ground outside? Does an outside wire perform better if it's grounded or is it a safety precaution (or both)? It's mainly a safety issue, since you can't make a good RF signal ground for the type of antenna you're considering (random wire or inverted-L), *unless* you use the technique on the following website: http://www.anarc.org/naswa/badx/ante...e_antenna.html An RF signal ground needs to be short. Several feet of ground wire is too much. That's why the grounding method on the website (above) works so well. The ground wire to the rod is very short. Mine is about 12-inches. Even if you're not interested in reducing noise with a good RF ground, it's still a good idea to have some kind of ground for lightning or just static electricity. I suggest you install a ground rod near the location where the antenna wire comes inside the house. Connect a lightning arrestor between the antenna lead wire and the rod. Better yet, build the antenna design on the website above. This method helps to reduce noise from domestic appliances such as televisions and computers. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Hey starman,
I am still trying to digest the material on the website you listed. I even found another website that referrences this one, and has pictures. I am still not clear on the purpose of the 30turn/10turn matching transformer inside the shielded box. What does this accomplish that a 300/75 ohm matching transformer between 300 ohm twinlead and 75 ohnm coax would not? Also I am planning on grounding the shield of the coax to a grounding stake at the "base" of the antenna, as soon as the coax comes near enough to the ground to do this. How can I do better than that, for a ground? I do appreciate your patience. "starman" wrote in message ... Jim Williams wrote: If I run a wire out the window to a tree near the house, do I also need to run a ground wire to the ground outside? Does an outside wire perform better if it's grounded or is it a safety precaution (or both)? It's mainly a safety issue, since you can't make a good RF signal ground for the type of antenna you're considering (random wire or inverted-L), *unless* you use the technique on the following website: http://www.anarc.org/naswa/badx/ante...e_antenna.html An RF signal ground needs to be short. Several feet of ground wire is too much. That's why the grounding method on the website (above) works so well. The ground wire to the rod is very short. Mine is about 12-inches. Even if you're not interested in reducing noise with a good RF ground, it's still a good idea to have some kind of ground for lightning or just static electricity. I suggest you install a ground rod near the location where the antenna wire comes inside the house. Connect a lightning arrestor between the antenna lead wire and the rod. Better yet, build the antenna design on the website above. This method helps to reduce noise from domestic appliances such as televisions and computers. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Dave wrote:
Hey starman, I am still trying to digest the material on the website you listed. I even found another website that referrences this one, and has pictures. I am still not clear on the purpose of the 30turn/10turn matching transformer inside the shielded box. What does this accomplish that a 300/75 ohm matching transformer between 300 ohm twinlead and 75 ohnm coax would not? The homemade matching transformer described on the website(s) is designed to work best at shortwave frequencies and AM(MW) too. A generic TV transformer (balun) is intended for a higher range of frequencies and usually doesn't work well below about 10-Mhz. The TV ferrite core is made with a material that operates best at TV frequencies. The website mentions removing the core from a TV balun for making the shortwave transformer but I recommend getting a type '43' material for the core. You can try a TV balun to see how well you receive the lower shortwave bands. It will almost certainly not perform well on the AM broadcast band. However as someone mentioned, this could be an advantage if you have a lot of strong AM stations in your area that interfere with shortwave reception. Also I am planning on grounding the shield of the coax to a grounding stake at the "base" of the antenna, as soon as the coax comes near enough to the ground to do this. How can I do better than that, for a ground? The low noise antenna on the website is the best way to achieve a good RF ground for an inverted-L (random wire). This is because the antenna end of the coax is located close to the ground. Otherwise you should ground the shield of the coax when it first comes near the ground. This will require the grounding block I mentioned in the previous post. I do appreciate your patience. "starman" wrote in message ... Jim Williams wrote: If I run a wire out the window to a tree near the house, do I also need to run a ground wire to the ground outside? Does an outside wire perform better if it's grounded or is it a safety precaution (or both)? It's mainly a safety issue, since you can't make a good RF signal ground for the type of antenna you're considering (random wire or inverted-L), *unless* you use the technique on the following website: http://www.anarc.org/naswa/badx/ante...e_antenna.html An RF signal ground needs to be short. Several feet of ground wire is too much. That's why the grounding method on the website (above) works so well. The ground wire to the rod is very short. Mine is about 12-inches. Even if you're not interested in reducing noise with a good RF ground, it's still a good idea to have some kind of ground for lightning or just static electricity. I suggest you install a ground rod near the location where the antenna wire comes inside the house. Connect a lightning arrestor between the antenna lead wire and the rod. Better yet, build the antenna design on the website above. This method helps to reduce noise from domestic appliances such as televisions and computers. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Dan Graves wrote:
I'm curious as to how you can have such a short lead to the ground rod? It's more than 12" from my radios to the window. Doesn't the ground wire connect to the ground connection on the radios? Thanks, Dan The inverted-L antenna design we've been talking about uses a coax lead which goes to a box near the ground rod. The coax doesn't go up to the end of the antenna wire overhead. There is a single wire coming down from one end of the horizontal section of the antenna to the matching transformer, located in the box near the ground. This allows for a really short ground wire from the box to the rod. That's why mine is only 12-inches. Since the coax shield is grounded outside at the box and rod, there isn't any need for a seperate ground wire to the receiver. The receiver gets grounded by the coax shield where it connects to the receiver's antenna input. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"-=jd=-" wrote in message ... On Wed 21 Apr 2004 04:49:51p, "Dave" wrote in message : I am planning on grounding the shield of the coax to a grounding stake at the "base" of the antenna, as soon as the coax comes near enough to the ground to do this. How can I do better than that, for a ground? There's no harm in grounding the shield. I had a transformer with both grounds connected to the shield. It worked. When I changed it so that the primary (antenna side) connected the antenna to ground and the secondary (receiver side) connected the shield to the center conductor, Signal levels increased dramatically. In your case, your tv transformer was designed to work with tv freqs (above HF). It may work just fine for you - it may be a big bag of suck. Try it and see is the best advice. We could swap transformers and both get better/worse/nochange results than what we had before. Just because something works for someone else in here, that does not automatically mean it will work for you. There are too many variables. A general rule of thumb is that your antenna won't do you any good until you put the thing up, so quit talking about it and string it. Then come back here and tell us what your results are. It may be just right (with no further fiddling required) for what you want to do. However, if your radio is deaf, or overloaded after you put your antenna up, there is probably someone in here that can help you. Step One: Hang the antenna. You can mod it later if you need/want to. -=jd=- -- My Current Disposable Email: (Remove YOUR HAT to reply directly) Believe it or not, that is pretty much what I have decided to do, as soon as time permits. I thought I would be stringing it yesterday, then today. Tomorrow is pretty much out, and then I am going to be out of town for a few days. Will have to get it some time next week (probably Thursday.) In the meantime I am trying to find the most likely design to try first. I know nothing ever works as well as you want the first time out, but am still trying to find out as much as I can about this business. Thanks, Dave |
DAVE,
An OutSide Ground for Better Safety and more . . . http://groups.yahoo.com/group/Shortw...na/message/206 The "Grounding-Point" = Ground Rods and Ground Wires ETC. http://groups.yahoo.com/group/Shortw...na/message/425 The "Primary" Antenna Grounding Point and the 'secondary' Shack Grounding Point http://groups.yahoo.com/group/Shortw...na/message/503 TBL: Build your Antenna and Radio System from... the Ground Up :o) iane ~ RHF .. .. = = = "Dave" wrote in message = = = ... Hey starman, I am still trying to digest the material on the website you listed. I even found another website that referrences this one, and has pictures. I am still not clear on the purpose of the 30turn/10turn matching transformer inside the shielded box. What does this accomplish that a 300/75 ohm matching transformer between 300 ohm twinlead and 75 ohnm coax would not? Also I am planning on grounding the shield of the coax to a grounding stake at the "base" of the antenna, as soon as the coax comes near enough to the ground to do this. How can I do better than that, for a ground? I do appreciate your patience. "starman" wrote in message ... Jim Williams wrote: If I run a wire out the window to a tree near the house, do I also need to run a ground wire to the ground outside? Does an outside wire perform better if it's grounded or is it a safety precaution (or both)? It's mainly a safety issue, since you can't make a good RF signal ground for the type of antenna you're considering (random wire or inverted-L), *unless* you use the technique on the following website: http://www.anarc.org/naswa/badx/ante...e_antenna.html An RF signal ground needs to be short. Several feet of ground wire is too much. That's why the grounding method on the website (above) works so well. The ground wire to the rod is very short. Mine is about 12-inches. Even if you're not interested in reducing noise with a good RF ground, it's still a good idea to have some kind of ground for lightning or just static electricity. I suggest you install a ground rod near the location where the antenna wire comes inside the house. Connect a lightning arrestor between the antenna lead wire and the rod. Better yet, build the antenna design on the website above. This method helps to reduce noise from domestic appliances such as televisions and computers. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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