Mail Archive Search: <+from:i4jmy@iol.it>

Results:

References: [ +from:i4jmy@iol.it: 139 ]

Total 139 documents matching your query.

81. Topband: 2 wire beverage (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Fri, 22 Sep 2000 18:42:30 +0200; Hi Tom, althought agreeing with you in theory, let me insist, if I say something it's because I repeatitively tested on field, not just. One wire grounded and one floating did produce that amount of; /archives//html/Topband/2000-09/msg00132.html (8,230 bytes)
82. R: Topband: How to orient the receive antenna? (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Tue, 1 Aug 2000 22:30:48 +0200; Beverage antennas start to have a rather sharp forward pattern when their lenght exceed three wavelenghts. It's not usual to have such lenghts for 160m, but since beverages are not single band antenn; /archives//html/Topband/2000-08/msg00004.html (9,030 bytes)
83. Topband: Re: 160m RX (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Thu, 24 Aug 2000 15:31:31 +0200; sensitivity input only need MOSFET would Not necessarily everyone uses efficient antennas on reception, expecially on 160m. Loops or Pennants, not counting beverages with long runs of lossy cable wi; /archives//html/Topband/2000-08/msg00091.html (10,837 bytes)
84. Topband: Re: (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Sat, 26 Aug 2000 13:20:01 +0200; A receiver system needs the bests possible dynamic range within a good NF. Between two receivers with same blocking level, that one with better NF is definitely the best or, reversing the point, stat; /archives//html/Topband/2000-08/msg00106.html (7,226 bytes)
85. Topband: radials for verticals (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Sun, 27 Aug 2000 13:12:45 +0200; A vertical dipole still needs a good ground to be efficient at low angles and have no advantages over a quarter wave radiator. The center feed is an arbitrary feature and an half wave dipole can be a; /archives//html/Topband/2000-08/msg00112.html (8,499 bytes)
86. R: Topband: 240' tower (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Mon, 7 Feb 2000 23:50:13 +0100; The main problem in the half wave vertical, to achieve the theorical gain, is in the peculiar distribution of the current return path that follows the radiator's current distribution and therefore fi; /archives//html/Topband/2000-02/msg00052.html (7,617 bytes)
87. R: Topband: 2 wire beverage - transformers (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Tue, 8 Feb 2000 23:02:25 +0100; One of the impedances is that of the line composed by the 2 wires. The other impedance is that of the above line and ground. The balanced transformer is needed to obtain the reverse direction and can; /archives//html/Topband/2000-02/msg00061.html (7,014 bytes)
88. Topband: TG9 (score: 1): Author: i4jmy@iol.it (i4jmy@iol.it); Date: Wed, 23 Feb 2000 14:49:32 +0100; I've just received an "help request" e-mail from Luca. He has problems with the 160m antenna. I'll try to help him as I can understand the nature of the problem. 73, Mauri I4JMY -- FAQ on WWW: http:/; /archives//html/Topband/2000-02/msg00161.html (6,630 bytes)
89. R: Topband: Beverage now too short? (score: 1): Author: Maurizio Panicara" <i4jmy@iol.it (Maurizio Panicara); Date: Mon, 3 Jan 2000 19:03:07 +0100; It's no wonder for me because I always found that beverages much shorter than one wavelength do not work. You can try other transformer ratios to maximize the energy transfer from the antenna to the; /archives//html/Topband/2000-01/msg00010.html (7,282 bytes)
90. R: Topband: Vertical on tophill loc. ? (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Fri, 7 Jan 2000 17:17:37 +0100; The geometrical derived assumption that a sloping ground lowers the radiation peak is probably valid when the terrain is good, its slope moderate, free of discontinuities and extends for several wave; /archives//html/Topband/2000-01/msg00040.html (7,983 bytes)
91. R: R: Topband: Vertical on tophill loc. ? (score: 1): Author: Maurizio Panicara" <i4jmy@iol.it (Maurizio Panicara); Date: Sat, 8 Jan 2000 17:42:36 +0100; No wonder if a well designed vertical GP, placed in a good ground area, is an average better transmitter than an horizontal dipole placed half wave or less from ground. Same no wonder if different lo; /archives//html/Topband/2000-01/msg00058.html (8,139 bytes)
92. R: Topband: Receiver Dynamic Range (score: 1): Author: Maurizio Panicara" <i4jmy@iol.it (Maurizio Panicara); Date: Mon, 10 Jan 2000 00:56:57 +0100; The bandwith of pulsed signals exists but actually most of the problem lay in the phase noise of the PLLs used in the transmiters that spreads some energy in the spectrum around the nominal frequency; /archives//html/Topband/2000-01/msg00077.html (8,761 bytes)
93. R: Topband: Inverted L (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Mon, 24 Jan 2000 16:10:38 +0100; The impedance of a 23m top loaded vertical shouldn't match 1.2:1 to 50 ohm unless somewere losses are present and add to the impedance at resonance that should range in the 20-25 ohm area.. 90% the w; /archives//html/Topband/2000-01/msg00200.html (7,268 bytes)
94. R: Topband: terminated or not? (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Sat, 4 Dec 1999 18:37:59 +0100; Without directionality the S/N is deteriorated. Sometimes this is not acceptable. You could at least arrange to remotely switch, on and off, the teminating resistor. 73, Mauri I4JMY --Messaggio Origi; /archives//html/Topband/1999-12/msg00049.html (8,449 bytes)
95. R: Topband: Dipole/Reflector (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Tue, 14 Dec 1999 22:47:09 +0100; This is a multi-part message in MIME format. --=_NextPart_000_0023_01BF4685.279F28C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit --Messaggio Originale-- Da: Mike Mi; /archives//html/Topband/1999-12/msg00122.html (9,474 bytes)
96. R: Topband: Re: Folded Unipole vs Series Fed Antenna (score: 1): Author: Maurizio Panicara" <i4jmy@iol.it (Maurizio Panicara); Date: Thu, 16 Dec 1999 09:08:09 +0100; This kind of antenna is definitely unefficient and it's not any more a folded unipole in most of its range. Actually, for most of the octaves of the planned use, you were dealing with a sort of small; /archives//html/Topband/1999-12/msg00154.html (7,872 bytes)
97. R: Topband: GAP (score: 1): Author: Maurizio Panicara" <i4jmy@iol.it (Maurizio Panicara); Date: Sat, 18 Dec 1999 16:01:04 +0100; If the loading is made with a top hat and the ground plane is good, a 45 ft radiator can be quite efficient. The only matter could be the narrow bandwith and the deal to realize a matching unit with; /archives//html/Topband/1999-12/msg00188.html (7,718 bytes)
98. R: R: Topband: GAP (score: 1): Author: Maurizio Panicara" <i4jmy@iol.it (Maurizio Panicara); Date: Mon, 20 Dec 1999 10:18:45 +0100; Each Marconi's vertical antenna works against ground and if the ground is bad its efficiency drops. Short antennas suffers much more about this problem as Rr lowers and losses require to be minimized; /archives//html/Topband/1999-12/msg00214.html (8,536 bytes)
99. R: Topband: 'Cloth ears' (score: 1): Author: Maurizio Panicara" <i4jmy@iol.it (Maurizio Panicara); Date: Fri, 5 Nov 1999 19:15:58 +0100; This is a multi-part message in MIME format. --=_NextPart_000_0047_01BF27C2.30A01740 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Receiving is mainly a m; /archives//html/Topband/1999-11/msg00031.html (8,588 bytes)
100. Topband: IG9A Photos (score: 1): Author: i4jmy@iol.it (Maurizio Panicara); Date: Sat, 6 Nov 1999 20:43:40 +0100; If someone is interested, we updated (and it will grow) the IG9A page with photos and descriptions http://www.qsl.net/ig9-cqww99/picture.htm 73, Mauri I4JMY (one of IG9A & IR4T) E-mail: i4jmy@iol.it; /archives//html/Topband/1999-11/msg00038.html (6,617 bytes)

Current List: 81 - 100
Page: [1] [2] [3] [4] [5] [6] [7]