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21. Topband: Switching in Extra Antenna Length (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Thu, 04 Jul 2002 10:34:02 +0100; Personally I do not find practical and reliable to install a switch at a voltage point. At the edge of a quarterwave vertical there are tens thousand or even hundred thousands volts. An interesting a; /archives//html/Topband/2002-07/msg00035.html (9,523 bytes)
22. Topband: Re: Topband: Flattop "T" vs. Horizontal Loop (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Tue, 16 Jul 2002 12:05:14 +0200; If the noise you get is within the antenna's near field it's almost sure that nothing will change with the horizontal loop. What change for sure will be the 160m efficiency (TX) that will surely turn; /archives//html/Topband/2002-07/msg00101.html (8,553 bytes)
23. Topband: Re: Topband: TOP BAND RECEIVING ANTENNAS (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Tue, 8 Jan 2002 09:07:56 +0100; ctive Hi Oms, I don't think there are finally so many options. You don't need compromise antennas whose main feature is to develop a null or antennas whose directivity is big but efficiency too low; /archives//html/Topband/2002-01/msg00044.html (7,256 bytes)
24. Topband: Re: [CQ-Contest] Re: Topband: TOP BAND RECEIVING ANTENNAS (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Tue, 8 Jan 2002 17:31:42 +0100; I'm not convinced that any low band antenna has enough efficiency for all receivers, all cases, and expecially if the receiver BW is not for a narrow CW. This is also a great opportunity to explain; /archives//html/Topband/2002-01/msg00046.html (8,634 bytes)
25. Topband: Surgestions for split Freq required - CQWW 160 CW-SSB Contests (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Fri, 11 Jan 2002 23:29:54 +0100; In my opinion this appear not to be a good idea in order to produce the best possible score. Why settling to work split with USA where iso-frequency operation is allowed is a bit meaningless and the; /archives//html/Topband/2002-01/msg00067.html (7,929 bytes)
26. Topband: Fwd: re: [CQ-Contest] 2003 CQ 160 Change Coming (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Wed, 21 Nov 2001 12:39:25 +0100; -- Initial Header -- To : w4an@contesting.com Cc : cq-contest@contesting.com Date : Wed, 21 Nov 2001 11:00:38 +0100 Subject : re: [CQ-Contest] 2003 CQ 160 Change Coming us A 48 hour format is surely; /archives//html/Topband/2001-11/msg00079.html (10,389 bytes)
27. Topband: shunt feed help needed (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Mon, 8 Oct 2001 13:27:30 +0200; be The point where to attach the gamma rod, the distance from tower and the ratio between the tower and the rod itself play all a significant role. What finally should be a convenient 50 +JX is the; /archives//html/Topband/2001-10/msg00048.html (8,994 bytes)
28. Topband: Shunt-feeding (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Wed, 10 Oct 2001 12:13:30 +0200; meter will Since someone could wrongly argue that voltage and arcing are the only problem, it's wise to point out that the strap connecting the center of a yagi element to the boom could carry a not; /archives//html/Topband/2001-10/msg00072.html (7,993 bytes)
29. Topband: Shuntfeeding (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Fri, 12 Oct 2001 23:46:01 +0200; over Yes, but beyond a certain limit the obtained improvement is totally neglectable. Not necessarily. The radials should be long enough to reach areas where the current is highest or still consider; /archives//html/Topband/2001-10/msg00095.html (8,337 bytes)
30. Topband: Shunt feed foiled (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Sun, 14 Oct 2001 15:47:01 +0200; In theory it's possible for a feed line and other cables to leave the tower in any point, if you're able to decouple in that point and to minimize common mode currents. Practical reasons suggest tha; /archives//html/Topband/2001-10/msg00102.html (6,951 bytes)
31. Topband: Again about 160m bandplans (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Fri, 19 Oct 2001 22:42:37 +0200; In the last 10 years I used to work split during my 160m ssb contests from IR4T when conditions allowed Eu-Na traffic. I found this way much more effective for me: better reception, and good to speed; /archives//html/Topband/2001-10/msg00164.html (8,446 bytes)
32. Topband: Re: Top fed vertical (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Wed, 1 Aug 2001 20:51:48 +0200; Neglecting some practical disdvantages that may occurr, a generator can be placed wherever one likes most along an antenna. In any case, to maximize the energy transfer, the generator impedance must; /archives//html/Topband/2001-08/msg00003.html (7,503 bytes)
33. Topband: Terminating System for Beverages (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Sun, 12 Aug 2001 12:52:24 +0200; The vertical part of a working beverage is a minor problem. In my opinion and experience, your 10 Ft of height from ground is instead a much bigger problem since the whole antenna at such heights beg; /archives//html/Topband/2001-08/msg00042.html (7,581 bytes)
34. Topband: Terminating System for Beverages (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Tue, 14 Aug 2001 22:14:31 +0100; I've used many times your same system and I can confirm there was no interaction, at least up to a *density* of one Beverage each 40 degrees. 73, Mauri I4JMY; /archives//html/Topband/2001-08/msg00060.html (7,474 bytes)
35. Topband: Antennas (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Mon, 27 Aug 2001 11:55:54 +0200; Sloping down the capacitive loading wires you actually shorten the antenna. If the loading wires are long and consistently sloped, you mainly radiate with those wires instead of with the vertical sec; /archives//html/Topband/2001-08/msg00113.html (8,664 bytes)
36. Topband: Antennas (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Mon, 27 Aug 2001 23:03:19 +0200; Hi Tom & all, a 45 degrees inclination is acceptable with relatively tall antennas but not so much with shorter ones. With shorter radiators such an inclination (slope), and using hat wires long eno; /archives//html/Topband/2001-08/msg00122.html (9,111 bytes)
37. Topband: Antennas (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Tue, 28 Aug 2001 09:39:39 +0200; even Hi Tom, I think You missed the point that's not if an hat is or not a smart loading method, but if using that method what's wiser to do. As much as a vertical is getting shorter and the capacit; /archives//html/Topband/2001-08/msg00130.html (8,923 bytes)
38. Topband: Drooping top hats (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Wed, 29 Aug 2001 11:38:55 +0200; Here some calculations/modeling: All wires copper= #12 Vertical = 30 ft Hat (resonating)= 58-60 ft (x4) Ground = no losses Case 1, horizontal hat Rr = 5.5 Ohm Case 2, hat edges at 15 ft. Rr = 3.2 Ohm; /archives//html/Topband/2001-08/msg00141.html (8,342 bytes)
39. Topband: TOP LOAD! (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Thu, 30 Aug 2001 20:06:13 +0200; the Luckily most people love to understand how does something works and how to make it working better, others are mostly interested in the amateur "traffic", so spending their time to maximize oppor; /archives//html/Topband/2001-08/msg00152.html (7,171 bytes)
40. Topband: Chokes - ferrite vs air (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Thu, 14 Jun 2001 15:17:20 +0200; It's possible to use air core chokes, I mean chokes made with coaxial cable, if the reactance is large enough. In 160m this is easier since an RG58 wound on a plastic cylinder can be used and withst; /archives//html/Topband/2001-06/msg00031.html (7,565 bytes)

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