Search String: Display: Description: Sort:

Results:

References: [ +from:jim@luxfamily.com: 308 ]

Total 308 documents matching your query.

281. Re: [TowerTalk] Using Mastrant rope guying Rohn 45 (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Mon, 31 Jul 2023 11:30:59 -0700
On 7/31/23 10:01 AM, Tom Hellem wrote: MarkThe Rohn book specifies guying at 3 levels for 100' of R45. Top guy called out at 1/4" EHS, and other two at 3/16" EHS. I think you could safely assume that
/archives//html/Towertalk/2023-07/msg00059.html (9,025 bytes)

282. Re: [TowerTalk] Exothermic welding mold (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 14 Aug 2023 13:58:23 -0400
  <snip> The powder is available on eBay.  The powder comes in pre-measured containers depending upon the size of the mold it was intended for, and there is always a bit of fine powder at the top for
/archives//html/Towertalk/2023-08/msg00020.html (7,982 bytes)

283. Re: [TowerTalk] Shack to service entrance ground (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Fri, 18 Aug 2023 16:00:44 -0700
On 8/18/23 8:32 AM, K8ZM wrote: I am getting close to my project of completely re-doing all coax and control cables entering the shack and "finally" have almost everything. I'll be installing an 8 Ft
/archives//html/Towertalk/2023-08/msg00026.html (10,322 bytes)

284. Re: [TowerTalk] Shack to service entrance ground (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Fri, 18 Aug 2023 16:42:46 -0700
On 8/18/23 4:21 PM, Jim Brown wrote: On 8/18/2023 4:00 PM, Lux, Jim wrote: OK - you're in sort of an interesting situation, because your "shack ground" electrode isn't part of the required grounding
/archives//html/Towertalk/2023-08/msg00029.html (10,617 bytes)

285. Re: [TowerTalk] Shack to service entrance ground (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Sat, 19 Aug 2023 09:28:28 -0700
<According the the ARRL Grounding and Bonding book, Good Practices and <Guidelines: <"Should I bond my tower to the station ground? <...Once the distance (between tower and station) exceeds 40 to 50
/archives//html/Towertalk/2023-08/msg00039.html (11,414 bytes)

286. Re: [TowerTalk] Shack to service entrance ground (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Sat, 19 Aug 2023 10:36:18 -0700
"Should I bond my tower to the station ground? ...Once the distance (between tower and station) exceeds 40 to 50 feet, however, the inductance of the ground conductor will be too high for the bond to
/archives//html/Towertalk/2023-08/msg00041.html (10,496 bytes)

287. Re: [TowerTalk] Opposing boom to mast plates? (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 25 Sep 2023 15:54:01 -0400
  Ultimately, it's kind of like EM modeling of an antenna. You can start with a dipole model. You can then go to a method of moments code. Then you can go to a monte carlo or systematic variation of
/archives//html/Towertalk/2023-09/msg00072.html (15,597 bytes)

288. Re: [TowerTalk] Antenna wire source? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Thu, 28 Sep 2023 10:04:14 -0700
Your experience with Flexweave does not match my experience.  I had an inverted vee up using flexweave and it was up for 8 years until I took it down and we do get some hellacious winds here in the P
/archives//html/Towertalk/2023-09/msg00086.html (10,786 bytes)

289. Re: [TowerTalk] : Antenna wire source? (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sat, 30 Sep 2023 15:22:12 -0400
Did you put the diameter of the wire into Brians program?  304SS in the tables shows up as 2.5 IACS (i.e. 2.5 times the resistance of copper).  Because its resistive, the skin depth is greater (by sq
/archives//html/Towertalk/2023-09/msg00093.html (11,318 bytes)

290. Re: [TowerTalk] copper tank coils (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sat, 30 Sep 2023 15:26:59 -0400
Tank coils and inductors are very different from antenna losses - In the former, you typically have larger current - A Q of 10 implies that there is 10 times as much power circulating in the LC as th
/archives//html/Towertalk/2023-09/msg00094.html (9,634 bytes)

291. Re: [TowerTalk] copper tank coils (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sat, 30 Sep 2023 15:38:43 -0400
Silver plating is usually very thin, and doesnt have a huge effect on the RF resistance.  One advantage is that silver oxide is conductive, copper oxide is lossy. Also, if you have a moving contact -
/archives//html/Towertalk/2023-09/msg00095.html (7,857 bytes)

292. Re: [TowerTalk] copper tank coils (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sun, 01 Oct 2023 20:46:48 -0400
More than one engineer has been bitten by the nickel flash under the gold plating on microwave circuits - similar to the discussion in the article.   Yeah, silver plating is usually done to make it l
/archives//html/Towertalk/2023-10/msg00003.html (8,514 bytes)

293. Re: [TowerTalk] Condensation Inside Tower Cable Box (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Mon, 16 Oct 2023 12:51:52 -0700
On 10/16/23 11:56 AM, Shawn Donley wrote: Hello fellow TowerTalkers, I have an aluminum outdoor electrical enclosure at the base of my tower. My underground runs of hardline enter the box through a P
/archives//html/Towertalk/2023-10/msg00040.html (8,935 bytes)

294. Re: [TowerTalk] Topband: Radial Attachment Plate (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Mon, 30 Oct 2023 17:41:46 -0700
Thanks for pointing me to that review. I looked at that picture. These are 304 grade stainless. DX Engineering's plate is the same - 304 stainless steel which is not the best for corrosion resistance
/archives//html/Towertalk/2023-10/msg00061.html (9,193 bytes)

295. Re: [TowerTalk] 3M External PIM Absorber 1000 | 3M United States (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sat, 18 Nov 2023 16:40:44 -0500
Ive used similar products at lower frequencies (<30 MHz) to good avail for knocking down RFI carried on power and data cables. Its basically a ferrite/powdered metal in a elastomeric binder, or you c
/archives//html/Towertalk/2023-11/msg00023.html (8,588 bytes)

296. Re: [TowerTalk] 3M External PIM Absorber 1000 | 3M United States (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sat, 18 Nov 2023 23:57:25 -0500
I was using 31 mix more as an example.  The data sheet for the tape or sheet gives curves for R and X. The big issue is, for HF, you dont want the stuff for microwaves (which is what most of them are
/archives//html/Towertalk/2023-11/msg00026.html (10,776 bytes)

297. Re: [TowerTalk] 3M External PIM Absorber 1000 | 3M United States (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sun, 19 Nov 2023 12:29:47 -0500
  Yes, exactly what I was thinking once you described what worked for you -- it's a new way of doing what W2DU did with beads 50 years ago. That sounds like a shielding failure if the conductor isn't
/archives//html/Towertalk/2023-11/msg00028.html (12,361 bytes)

298. Re: [TowerTalk] 3MT External PIM Absorber 1000 | 3M United States (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sun, 19 Nov 2023 15:05:38 -0500
Just like in coax chokes, you want to look at both the resistive and inductive properties - I would think that for PIM reduction, you want lossy rather than high inductive Z, but maybe high Z works,
/archives//html/Towertalk/2023-11/msg00032.html (10,441 bytes)

299. Re: [TowerTalk] ...and another coax adapter question (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 27 Nov 2023 09:53:26 -0500
One of those (the cheaper Amphenol-Connex) has gold over brass for the center pin, nickel over brass for the barrel, and teflon for the dielectric.  The other one is nickel over brass for the barrel,
/archives//html/Towertalk/2023-11/msg00088.html (15,068 bytes)

300. Re: [TowerTalk] Open-wire transmission line (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Sun, 31 Dec 2023 10:55:14 -0500
I suspect the popularity of 600 ohms is because that is the standard Z of an open wire voice/telegraphy pair from the 19th century. And *that* is probably determined by the physical size of insulator
/archives//html/Towertalk/2023-12/msg00076.html (10,415 bytes)


This search system is powered by Namazu