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1. Topband: Beacons or ref. signals for topband? (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Sun, 5 Aug 2001 21:54:50 -0400; Let's not forget the digital signals on 1803.5 from somewhere in north east Africa, and the one on 1851 from Europe. Also 1816.5 from Hawks Bay in the NE of the north island of New Zealand, and the o; /archives//html/Topband/2001-08/msg00022.html (7,316 bytes)
2. Topband: Last-ditch effort: elavated radiation... (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Tue, 7 Aug 2001 12:35:11 -0400; The hat simply serves to make current uniform throughout the structure. It primarily reduces losses because uniform current maximizes loop radiation resistance. Taller structures always yield more r; /archives//html/Topband/2001-08/msg00026.html (10,264 bytes)
3. Topband: Simple motor driven telescoping aluminum vertical for (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Wed, 18 Jul 2001 12:34:05 -0400; low bands? Reply-to: W8JI@contesting.com CC: topband@contesting.com Sender: owner-topband@contesting.com Precedence: bulk X-Mailing-List: topband@contesting.com X-List-Info: http://www.contesting.com; /archives//html/Topband/2001-07/msg00032.html (9,282 bytes)
4. Topband: Drake R4C (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Sun, 22 Jul 2001 21:30:50 -0400; Sender: owner-topband@contesting.com Precedence: bulk X-Mailing-List: topband@contesting.com X-List-Info: http://www.contesting.com/FAQ/topband X-Sponsor: W4AN, KM3T, N5KO & AD1C All Drake R4C's wil; /archives//html/Topband/2001-07/msg00040.html (8,374 bytes)
5. Topband: Feedlines (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Wed, 25 Jul 2001 10:41:21 -0400; While regular cable is OK above ground in areas free of critters, I use flooded RG-6 (F6) for shorter runs (less than 1000 feet) and RG- 11 (F11) for long runs. Flooded cable normally has a very tou; /archives//html/Topband/2001-07/msg00052.html (7,286 bytes)
6. Topband: What wire to use for 'wire' TX antenna (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Thu, 26 Jul 2001 08:51:14 -0400; Woven or braided conductors have a lot more resistance per unit length than smooth surface conductors. Clean, shiny braid that is compressed (like the braid inside coax, compressed by the jacket) ha; /archives//html/Topband/2001-07/msg00055.html (8,484 bytes)
7. Topband: New Beverage article (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Fri, 27 Jul 2001 22:41:13 -0400; For low-band ops...I just posted a new Beverage article at www.w8ji.com that describes how to phase staggered or Echelon Beverages. It describes two different broadband phasing systems that can enhan; /archives//html/Topband/2001-07/msg00065.html (6,740 bytes)
8. Topband: Wire Guage VS Resistance (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Sat, 28 Jul 2001 19:10:20 -0400; Hi Thomas, I know it was a lot of work, but you quoted dc resistance. DC resistance and RF resistance are entirely different. Tables for dc or very low frequency ac do not reflect the resistance at r; /archives//html/Topband/2001-07/msg00071.html (8,171 bytes)
9. Topband: RF resistance of wire (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Tue, 31 Jul 2001 10:11:44 -0400; In amplifier tank circuits at HF carrying high current, braid from RG- 8/U will overheat and melt while #14 tinned buss wire will barely get warm. If you simply tin the length of braid making it one; /archives//html/Topband/2001-07/msg00085.html (8,471 bytes)
10. Topband: Top Fed Vertical (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Tue, 31 Jul 2001 13:08:56 -0400; Hi Doug, As Roy points out, you can move the feedpoint all you like and losses remain the same. The only way to minimize losses in a short antenna is to make current as uniform as possible in the str; /archives//html/Topband/2001-07/msg00086.html (8,204 bytes)
11. Topband: Feed Line (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Tue, 12 Jun 2001 12:34:41 -0400; A transmission line stub, other than providing matching, radiates. We have the very same common-mode current problems we have with open wire line right into the shack. We just satisfy the SWR issues; /archives//html/Topband/2001-06/msg00023.html (8,224 bytes)
12. Topband: Chokes - ferrite vs air (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Sat, 16 Jun 2001 05:52:57 -0400; Hi Gary, The problem isn't saturation, it's good old fashioned dissipation. Most ferrites have fairly low Q on higher frequencies. 73 material has a Q of one around 2 MHz or so. While this doesn't hu; /archives//html/Topband/2001-06/msg00040.html (9,723 bytes)
13. Topband: Chokes-Ferrite vs. air (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Wed, 20 Jun 2001 23:47:18 -0400; Hi Barry and all, Interesting topic.. The choke impedance required actually depends on the common mode impedance of the system at the point where the choke is installed, and how sensitive the system; /archives//html/Topband/2001-06/msg00052.html (8,902 bytes)
14. Topband: Receive Antennas (score: 1): Author: w8ji@akorn.net (Tom Rauch); Date: Wed, 27 Jun 2001 10:57:13 -0400; The start of an antenna article is posted now on the W8JI.com web site. The article describes how and why near field and induction field coupling is unpredictable, and does explain (I hope) how to pr; /archives//html/Topband/2001-06/msg00062.html (7,333 bytes)
15. Topband: Loopsticks on 160 (score: 1): Author: W8JI@akorn.net (Tom Rauch); Date: Mon, 19 Feb 2001 22:41:04 -0500; Hi Ford, This is an excellent demonstration of the false myth that this an other small loops are "magnetic radiators" and are not influenced by electric fields. You are holding the loop so the magnet; /archives//html/Topband/2001-02/msg00061.html (10,225 bytes)

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