Search String: Display: Description: Sort:

Results:

References: [ +from:martin.ewing@gmail.com: 23 ]

Total 23 documents matching your query.

1. Re: [TowerTalk] lightning & trees (score: 1)
Author: Martin Ewing <martin.ewing@gmail.com>
Date: Fri, 18 Mar 2005 13:53:15 -0500
The more familiar way (for me) to say it is that the electric field (volts/meter) produced by a conductor at a certain voltage relative to a distant object depends on the "sharpness" of the conductor
/archives//html/Towertalk/2005-03/msg00558.html (10,270 bytes)

2. Re: [TowerTalk] Isolation Transformer (score: 1)
Author: Martin Ewing <martin.ewing@gmail.com>
Date: Sun, 20 Mar 2005 13:19:36 -0500
Gene, Here are my 2 cents. A transformer _can_ provide some protection against HF signals & transients that may come in on the line, but most transformers aren't designed for that kind of isolation.
/archives//html/Towertalk/2005-03/msg00679.html (9,577 bytes)

3. Re: [TowerTalk] polyrod (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Tue, 3 May 2005 11:14:51 -0400
Solar heating of materials is not a "black and white" issue. You have to think about wavelengths. The input from the Sun (after atmospheric effects) is primarily in the visible wavelengths. (That's w
/archives//html/Towertalk/2005-05/msg00056.html (12,139 bytes)

4. Re: [TowerTalk] Bird loading and elements (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Wed, 4 May 2005 20:20:40 -0400
It's a dynamics problem, not only statics. Those birds are conducting flight operations after all. If you shoot at them, they'll all take off at once, and then you'll be sorry. That's if they jump up
/archives//html/Towertalk/2005-05/msg00113.html (9,671 bytes)

5. [TowerTalk] Ground strap to water pipe? (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Sun, 8 May 2005 15:29:53 -0400
Wisdom, please: I want to run 1.5 inch copper strap from my SPG bulkhead to my AC ground point, which is my water service entrance, following the "bond the grounds together" principle. Question is wh
/archives//html/Towertalk/2005-05/msg00177.html (7,564 bytes)

6. Re: [TowerTalk] Ground strap to water pipe? (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Sun, 8 May 2005 22:19:52 -0400
I can add a few details. I am indeed in CT, on a granite ledge about 100 ft from the Long Island Sound. There is a few feet of soil over the ledge. The water entrance is "city water", and it runs met
/archives//html/Towertalk/2005-05/msg00182.html (9,794 bytes)

7. Re: [TowerTalk] Ground strap to water pipe? (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Mon, 9 May 2005 10:06:03 -0400
Several folks have pointed me to the Polyphaser copper strap to galvanized pipe clamps (e.g., model TK-2) using a stainless steel intermediate layer. That's probably what I am looking for, or for mor
/archives//html/Towertalk/2005-05/msg00185.html (8,827 bytes)

8. Re: [TowerTalk] Ground strap to water pipe (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Tue, 10 May 2005 11:53:44 -0400
Some are saying stainless steel is the right stuff to put between copper and zinc (galvanized). Rob thinks brass is the right material. Zinc to galvanizing (zinc dip) is obviously harmless (no electr
/archives//html/Towertalk/2005-05/msg00221.html (11,385 bytes)

9. Re: [TowerTalk] SWR is what SWR meter measures (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Fri, 13 May 2005 08:59:30 -0400
I'd rather say that "impedance at the transmission line" and "forward / reverse / circulating power" are just different ways of analyzing the same physical system. Sometimes one is more useful that t
/archives//html/Towertalk/2005-05/msg00323.html (11,622 bytes)

10. Re: [TowerTalk] SWR is what SWR meter measures (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Fri, 13 May 2005 11:02:53 -0400
I hope there's more light than heat (forward or backward) in this discussion. Anyway, the common SWR meter samples forward and reverse power by adding a current sample and a voltage sample. This make
/archives//html/Towertalk/2005-05/msg00330.html (12,106 bytes)

11. Re: [TowerTalk] SWR is what SWR meter measures (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Fri, 13 May 2005 12:08:43 -0400
Gary, An impedance mismatch is the same thing as a reflector. How do you think mirrors work? It's a matter of perspective. "Reality" of power flow is debatable. Let me describe it from my viewpoint a
/archives//html/Towertalk/2005-05/msg00335.html (13,972 bytes)

12. Re: [TowerTalk] Text Messaging VS CW Results - Jay Leno Show (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Sun, 15 May 2005 00:14:46 -0400
Well I think my cell phone beats CW when it comes to sending pictures and mp3s, not to mention plain old voice! Theoretically, you could uuencode a voice file or photo and send by CW, but it wouldn't
/archives//html/Towertalk/2005-05/msg00387.html (8,899 bytes)

13. Re: [TowerTalk] Thief (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Tue, 17 May 2005 10:19:07 -0400
People should be aware that there is such a thing as libel, which is defamatory written speech. From freeadvice.com: "Defamation, sometimes called "defamation of character", is spoken or written word
/archives//html/Towertalk/2005-05/msg00478.html (9,324 bytes)

14. [TowerTalk] Fwd: Attaching Ground Braid (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Wed, 1 Jun 2005 10:02:54 -0400
I use 1" braid for this kind of thing, along with a 100 W soldering iron. Everyone needs a big iron once in a while... Washers (unsoldered) and wingnuts complete the job. 73 Martin AA6E martin.ewing@
/archives//html/Towertalk/2005-06/msg00011.html (8,529 bytes)

15. Re: [TowerTalk] A fundamental antenna question (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Mon, 27 Jun 2005 23:04:25 -0400
Good physics lesson, Jim. I'd add that truly isotropic antennas are physically impossible -- or at least unrealizable. Not that it matters much for practical purposes. 73 Martin AA6E - Hide quoted te
/archives//html/Towertalk/2005-06/msg00609.html (8,511 bytes)

16. [TowerTalk] omega demolition video (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Tue, 27 Sep 2005 21:34:47 -0400
I ran across an iFilm video at http://www.ifilm.com/ifilmdetail/2676026 that shows a 1998 Omega tower demolition. Awesome. 73 Martin AA6E -- martin.ewing@gmail.com http://blog.aa6e.net ______________
/archives//html/Towertalk/2005-09/msg00845.html (7,216 bytes)

17. Re: [TowerTalk] omega demolition video (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Wed, 28 Sep 2005 11:59:27 -0400
Makes a difference if a Cat 4 hurricane is blowing! The demolition (in still air) seemed to blow the guy wires and possibly the base. I didn't see any explosions up the tower, though there may have b
/archives//html/Towertalk/2005-09/msg00866.html (8,578 bytes)

18. Re: [TowerTalk] Lightning Protection Device Question (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Fri, 7 Oct 2005 15:31:24 -0400
Mike, People all have their favorites, but I would generally choose PP, which are widely used in the communications industry. You can have safety or you can have low cost. I'm not sure about both. Un
/archives//html/Towertalk/2005-10/msg00302.html (8,947 bytes)

19. Re: [TowerTalk] FW: The PERILS of single point grounding (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Fri, 7 Oct 2005 16:00:39 -0400
Jim, I agree with Gary. One way to look at this is to imagine that your shack is enclosed by solid metal ground walls. All your cables, including power, telephone, coaxes, etc., are surge protected a
/archives//html/Towertalk/2005-10/msg00308.html (14,320 bytes)

20. Re: [TowerTalk] FW: The PERILS of single point grounding (score: 1)
Author: "Martin, AA6E" <martin.ewing@gmail.com>
Date: Sun, 9 Oct 2005 21:43:17 -0400
Unfortunately (?) we don't all live in FL, and we don't get to test our ground systems on a regular basis. You can't really trust your ground system unless you can test it under realistic conditions.
/archives//html/Towertalk/2005-10/msg00394.html (9,083 bytes)


This search system is powered by Namazu