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References: [ +from:jim@luxfamily.com: 315 ]

Total 315 documents matching your query.

301. [TowerTalk] What *is* the optimum open wire line impedance (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 01 Jan 2024 15:32:24 -0500
Which brings up an interesting question.. What would the best impedance be for open wire line, assuming you have some sort of tuner at the feeding end, so you dont care from a drive standpoint. And a
/archives//html/Towertalk/2024-01/msg00003.html (7,304 bytes)

302. [TowerTalk] Trapped Antenna in the "formal" literature? (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 08 Jan 2024 18:06:28 -0500
I'm looking for a paper reference to basic trapped antenna design and performance, preferably in something like an IRE or AIEE journal (I'm sure it's pre-IEEE).  I'm writing a paper and I make a refe
/archives//html/Towertalk/2024-01/msg00019.html (7,232 bytes)

303. Re: [TowerTalk] Trapped Antenna in the "formal" literature? (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 08 Jan 2024 20:28:23 -0500
perfect... that's exactly the kind of thing I was looking for. https://ieeexplore.ieee.org/document/1141000 Abstract: The trap-loaded cylindrical antenna is a cylindrical antenna having one or more t
/archives//html/Towertalk/2024-01/msg00023.html (13,690 bytes)

304. Re: [TowerTalk] Trapped Antenna in the "formal" literature? (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 08 Jan 2024 20:36:50 -0500
  Here's an intersting one - can't find the actual paper, but it seems to be an antenna with a bunch of traps spaced in a log periodic way.  I also found someone who had one with 13 wires and 39 trap
/archives//html/Towertalk/2024-01/msg00024.html (14,993 bytes)

305. Re: [TowerTalk] Trapped Antenna in the "formal" literature? (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Tue, 09 Jan 2024 12:57:48 -0500
More interesting stuff.. Here's what's probably the original patent (oh for the days when a patent was only 3 pages...) https://patents.google.com/patent/US2229865A/en     Here's an intersting one -
/archives//html/Towertalk/2024-01/msg00026.html (15,952 bytes)

306. Re: [TowerTalk] Hairpin Match Calculator (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Thu, 11 Jan 2024 20:08:56 -0500
  This is why FEM codes exist - the analytical expressions get you most of the way there, but then as you start to find equations for more of the interactions, pretty soon you wind up at NEC - which
/archives//html/Towertalk/2024-01/msg00029.html (10,334 bytes)

307. Re: [TowerTalk] Hairpin Match Calculator (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Fri, 12 Jan 2024 10:49:36 -0500
  "NEC does use a simplified model for the "wire" - it takes into account dielectrics and skin effect (I'm in the middle of figuring out what ZINT does, which is the core of the "resistance and induc
/archives//html/Towertalk/2024-01/msg00031.html (9,857 bytes)

308. Re: [TowerTalk] Coax cable stripper (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Fri, 09 Feb 2024 11:40:47 -0500
I love the multi blade strippers with the interchangeable adjustable cassettes.  You can set them up for different kinds of coax, and when you swap, you just put in the already adjusted blade set.  M
/archives//html/Towertalk/2024-02/msg00019.html (8,299 bytes)

309. Re: [TowerTalk] Modeling a self supporting tower interaction (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 24 Jun 2024 16:48:01 -0400
There's two ways to approach the modeling.  The easiest is to model a "very thick" wire - match the surface area of the tower with the surface area of the wire. The less easy is to model all the piec
/archives//html/Towertalk/2024-06/msg00094.html (8,815 bytes)

310. Re: [TowerTalk] 80M Delta Loop (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Fri, 26 Jul 2024 17:49:59 -0400
And, from an antenna pattern standpoint, the dielectric constant (which is highly moisture content dependent) is important.  Id venture that changing epsilon from 4 to 16 has a much bigger effect tha
/archives//html/Towertalk/2024-07/msg00106.html (11,503 bytes)

311. Re: [TowerTalk] TowerTalk Digest, Vol 259, Issue 15 160 meter trap/coil (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 29 Jul 2024 15:10:48 -0400
  On VK4YB's qrz page -- it's the first drawing. It's that middle vertical section that does the radiating. Everything else is loading. When the ARRL website gets back up, you can look it up there. I
/archives//html/Towertalk/2024-07/msg00121.html (10,173 bytes)

312. [TowerTalk] low noise preamps for active whip antennas (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Wed, 25 Sep 2024 20:43:22 -0400
What's currently available out there as preamps for electrically short active whips.  Seems you get a lot of links to products that are no longer sold, or which have no meaningful data (like what's t
/archives//html/Towertalk/2024-09/msg00070.html (6,827 bytes)

313. Re: [TowerTalk] Tesla Power Wall Noise? (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Thu, 10 Oct 2024 13:17:34 -0400
  I've got 2 Powerwall 3's outside, I can go out with a spectrum analyzer and a whip and measure. Here's the possible problem: there are other parts of the system (the bridge/transfer switch) that mi
/archives//html/Towertalk/2024-10/msg00063.html (10,200 bytes)

314. Re: [TowerTalk] Tesla Power Wall Noise? (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Thu, 10 Oct 2024 13:19:24 -0400
  TH-F6A can be set for AM or SSB, and tunes well down into the HF and MF range.  I listen to WWVH on mine. Respectfully, this isn't a good test. Your HT is FM and per Wikipedia, "FM rejects radio fr
/archives//html/Towertalk/2024-10/msg00064.html (9,250 bytes)

315. Re: [TowerTalk] Identify old hard line (score: 1)
Author: "Jim Lux" <jim@luxfamily.com>
Date: Wed, 23 Oct 2024 15:55:55 -0400
You can get a length measurement from one end with a inexpensive (<$100) VNA like the NanoVNA. And you'll be able to tell if there's damage somewhere along the length. Thanks Ed. This length of line
/archives//html/Towertalk/2024-10/msg00086.html (9,802 bytes)


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