Posted: 7/17/2015 8:16:22 AM EDT
I bought a diamond cp6ar antenna with a military surplus tripod mast to mount it. What my options are to ground it? I've been reading up on my various options, but I figured I'd ask the experts at arfcom.  . Any help is appreciated.
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Will this be a permanent mount to the tripod? It sounds like the tripod is not metal. If not, then my recommendations would be. If temporary or occasional setup is the plan, hammer a ground rod in where the tripod is going to be and keep an appropriate length of #6 coiled up near there with a ring-clamp of the right size to clamp to the coax connection on the antenna. If permanent then I would do the same but I would get a lightning protection module and mount it where the coax gets closest to the ground and connect that to the ground rod. You might want to describe the overall setup a bit more to get more recommendations. |
| It is going to be semi temporary. I have a spot I'm going to use as my regular spot, but the mast and antenna will be put up and taken down, so I could put a grounding rod in and leave it. Does it matter how high up the ground wire is attached to the coax? Just want to order the correct length of ground wire. |
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Ideally you would run coax from the antenna to a lightning protection device on the ground rod, and from there to the shack.
less ideal is the separate ground from the antenna connector to the ground rod, with or without a LP module. If you aren't going to leave it out in the weather, and you only have the single length of coax, then the ground rod and wire with a clamp is the cheapest solution. Not having a proper ground and LP would make my skin crawl. |
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Are you talking about a safety/static drain ground, or the required ground plane/counterpoise needed to make a vertical work? The two are not the same.
If you expect to use all the bands, you will need a reasonable ground plane with a bunch of radial wires. For a semi-permanent installation I'd suggest maybe 8 to 16 wires of a length for 80m, 8 to 16 for 40, and 8 for 20. |
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Are you talking about a safety/static drain ground, or the required ground plane/counterpoise needed to make a vertical work? The two are not the same. If you expect to use all the bands, you will need a reasonable ground plane with a bunch of radial wires. For a semi-permanent installation I'd suggest maybe 8 to 16 wires of a length for 80m, 8 to 16 for 40, and 8 for 20. The antenna claims no radials needed. I suspect the OP is planning on mounting it as elevated as possible. |
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The antenna claims no radials needed. I suspect the OP is planning on mounting it as elevated as possible. Quoted:
Quoted:
Are you talking about a safety/static drain ground, or the required ground plane/counterpoise needed to make a vertical work? The two are not the same. If you expect to use all the bands, you will need a reasonable ground plane with a bunch of radial wires. For a semi-permanent installation I'd suggest maybe 8 to 16 wires of a length for 80m, 8 to 16 for 40, and 8 for 20. The antenna claims no radials needed. I suspect the OP is planning on mounting it as elevated as possible. I guess the question is, if you want it to work or not. |
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I guess the question is, if you want it to work or not. Quoted:
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Are you talking about a safety/static drain ground, or the required ground plane/counterpoise needed to make a vertical work? The two are not the same. If you expect to use all the bands, you will need a reasonable ground plane with a bunch of radial wires. For a semi-permanent installation I'd suggest maybe 8 to 16 wires of a length for 80m, 8 to 16 for 40, and 8 for 20. The antenna claims no radials needed. I suspect the OP is planning on mounting it as elevated as possible. I guess the question is, if you want it to work or not. No jumping ahead!!! 
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For "electrical ground" the antenna and mast must be connected to the main electric ground with a short run of wire. Avoid 90° corners.
We also usually try to ground the coax before it enters the house, but you must have at least one solid connection, from the mast/antenna, to the main electric ground before you plug in to the radio. |
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That is correct, I was planning on mounting it to the mast, as per the instructions claimed that radials were not necessary That is technically true. Because you must plug a coax into it, the coax and everything connected to it, becomes the radial. So you always get at least one radial. The current will find a path 20m long or more till it achieves electrical balance with the antenna. Technically you become an end fed Zepp antenna. You are the Zeppelin as the counterpoise, the other half of the dipole, to the antenna on the roof. Electrical/safety ground is a separate problem from radials. Although both can be solved with wire, how and why are different. |
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Reading through the destructions, it appears it uses coil loaded radials...interdasting. I'm sure it will do something. Actual radials would do more. If it achieves electrical balance at the feed point then coils can shorten the physical length of the counterpoise exactly the same way it shortens the vertical radiator. 2-4 loaded radials would be great. If the radial field is insufficient the current will still use the coax, and everything connected to it, as additional loading. Full length wire radials without the loading coils would be electrically identical. Either you provide the counterpoise, it will find a path or it just won't complete the electrical circuit, at that frequency. |
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That is correct, I was planning on mounting it to the mast, as per the instructions claimed that radials were not necessary http://www.walcottradio.com/images/CP6AR.jpg Quoted:
The antenna claims no radials needed. I suspect the OP is planning on mounting it as elevated as possible. That is correct, I was planning on mounting it to the mast, as per the instructions claimed that radials were not necessary http://www.walcottradio.com/images/CP6AR.jpg We used a similar antenna at Field Day last year with their tuned loaded radials on a mast and the performance was horrible. |
| Looks like a plain old trap vertical, it will suck without real radials and you can pretty much take that to the bank. If you want a vertical that will work without radials there are a number of center fed multiband verticals that will work better out of the box. They are more expensive, of course, and still probably not quite as good as a 1/4 wave with a proper set of radials. |