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Total 458 documents matching your query.

141. Re: Topband: Passive Receive Antenna Splitter (score: 1)
Author: donovanf@starpower.net
Date: Thu, 13 Mar 2014 23:52:54 -0400 (EDT)
Hi Gary, The most efficient way to share a Beverage among two (or as many as four) bands to use W3LPL bandpass filters. Loss of each filter is in the order of 1.5 dB vs. about 3.5 dB for a typical Ma
/archives//html/Topband/2014-03/msg00104.html (9,429 bytes)

142. Re: Topband: A newbie question (score: 1)
Author: donovanf@starpower.net
Date: Tue, 18 Mar 2014 14:19:21 -0400 (EDT)
Hi Tom, Welcome to topband! As you gain experience you will encounter many situations where your transmit antenna is inadequate for receiving. An excellent receiving antenna can provide as much as 10
/archives//html/Topband/2014-03/msg00141.html (9,500 bytes)

143. Re: Topband: IRC's (score: 1)
Author: donovanf@starpower.net
Date: Sun, 20 Apr 2014 10:07:04 -0400 (EDT)
Its simply untrue that foreign issued IRCs without a control stamp or postmark are worthless. See: http://pe.usps.gov/text/imm/immc3_020.htm "Under Universal Postal Unions regulations, participating
/archives//html/Topband/2014-04/msg00039.html (9,119 bytes)

144. Re: Topband: Feedpoint of short RX vertical (score: 1)
Author: donovanf@starpower.net
Date: Sat, 7 Jun 2014 15:17:29 -0400 (EDT)
Luc, I have not taken any steps to decouple the coaxial cable shield from the verticals in my 8-circle BSEF array. I use eight 23 meter long radials with each vertical. Its not clear to me how decoup
/archives//html/Topband/2014-06/msg00038.html (8,026 bytes)

145. Re: Topband: Feedpoint of short RX vertical (score: 1)
Author: donovanf@starpower.net
Date: Sat, 7 Jun 2014 16:08:56 -0400 (EDT)
Hi Frank, My 8-circle array uses low impedance verticals, not high impedance verticals like the Hi-Z. My verticals use an inductor and resistor at the base of each vertical. In a Hi-Z array each vert
/archives//html/Topband/2014-06/msg00041.html (8,817 bytes)

146. Re: Topband: 50 ohm direct burial coax cable (score: 1)
Author: donovanf@starpower.net
Date: Fri, 13 Jun 2014 16:01:13 -0400 (EDT)
You can easily make the 75 ohm coax essentially "invisible" in a monoband application by using some RG-11 to extend the total length of the 75 ohm feedline to any multiple of 1/2 wavelength. 73 Frank
/archives//html/Topband/2014-06/msg00080.html (9,658 bytes)

147. Re: Topband: 50 ohm direct burial coax cable (score: 1)
Author: donovanf@starpower.net
Date: Sat, 14 Jun 2014 11:24:50 -0400 (EDT)
A very useful feature of an approximate 1/2 wavelength (or multiple) of 75 ohm cable in a 50 ohm system is that its length can be trimmed to alter the impedance of the system. This simple trick is a
/archives//html/Topband/2014-06/msg00091.html (11,038 bytes)

148. Re: Topband: Length of Beverages (score: 1)
Author: donovanf@starpower.net
Date: Sat, 26 Jul 2014 11:39:13 -0400 (EDT)
Hi Bill, Longer Beverages provide narrower beamwidth, which reduces QRM or QRN that would be received through the main lobe of a shorter Beverage. (just like adding elements to a Yagi narrows its bea
/archives//html/Topband/2014-07/msg00047.html (8,157 bytes)

149. Re: Topband: Length of Beverages (score: 1)
Author: donovanf@starpower.net
Date: Sat, 26 Jul 2014 12:23:31 -0400 (EDT)
Hi Bill, I forgot to mention that my 8-circle vertical receiving arrays are specifically built for installation and removal in a single day They're installed on a nearby farm that I have access to on
/archives//html/Topband/2014-07/msg00048.html (8,266 bytes)

150. Re: Topband: Skimmer calibration (score: 1)
Author: donovanf@starpower.net
Date: Wed, 20 Aug 2014 03:47:35 -0400 (EDT)
Iceland: three people per square km Hello Mike You forget that on this side of the pond, the majority of us live on pocket handkerchief sized plots. :-) The representative of a major building company
/archives//html/Topband/2014-08/msg00214.html (9,202 bytes)

151. Re: Topband: Skimmer calibration (score: 1)
Author: donovanf@starpower.net
Date: Wed, 20 Aug 2014 03:49:24 -0400 (EDT)
Iceland: three people per square km. :) Hello Mike You forget that on this side of the pond, the majority of us live on pocket handkerchief sized plots. :-) The representative of a major building com
/archives//html/Topband/2014-08/msg00215.html (8,751 bytes)

152. Re: Topband: Modeling the proverbial "vertical on a beach" (score: 1)
Author: donovanf@starpower.net
Date: Wed, 20 Aug 2014 04:06:11 -0400 (EDT)
It's not necessary to place a vertical antenna at waters edge to gain the low angle efficiency advantages of an oceanfront site. There are two zones of interest: the area immediately adjacent to the
/archives//html/Topband/2014-08/msg00216.html (11,098 bytes)

153. Re: Topband: Outdoor rope suggestions (score: 1)
Author: donovanf@starpower.net
Date: Tue, 2 Sep 2014 18:28:54 -0400 (EDT)
I've tried all manor of industrial and homeowner pulleys and never found any to be suitable for long term outdoor use. For the last 25 years I've used 2.5 and 3 inch diameter sailboat pulleys (aka bl
/archives//html/Topband/2014-09/msg00028.html (10,527 bytes)

154. Re: Topband: WTB: Guy wire stuff (score: 1)
Author: donovanf@starpower.net
Date: Thu, 4 Sep 2014 13:40:02 -0400 (EDT)
Tower guys should use Big Grips, not the performs used by electric utilities. You can purchase Big Grips from Texas Towers and many other suppliers 73 Frank W3LPL If you only need a few like this, tr
/archives//html/Topband/2014-09/msg00045.html (10,242 bytes)

155. Re: Topband: WTB: Guy wire stuff (score: 1)
Author: donovanf@starpower.net
Date: Thu, 4 Sep 2014 15:34:15 -0400 (EDT)
Hi Greg, I've never seen a rated holding strength for Guy-Grips (the type used on wood poles). Big Grips are rated at 6650 pounds holding strength. Big Grips are two inches longer than Guy Grips. "Gu
/archives//html/Topband/2014-09/msg00052.html (9,925 bytes)

156. Re: Topband: WTB: Guy wire stuff (score: 1)
Author: donovanf@starpower.net
Date: Thu, 4 Sep 2014 15:43:28 -0400 (EDT)
Hi Carl, BG-2144 is the correct part number Big Grips for 1/4 inch guy wire attached to a tower. They're two inches longer than the Guy Grips for wood poles. See the Preformed Line Products Tower and
/archives//html/Topband/2014-09/msg00053.html (13,171 bytes)

157. Re: Topband: WTB: Guy wire stuff (score: 1)
Author: donovanf@starpower.net
Date: Thu, 4 Sep 2014 16:13:55 -0400 (EDT)
Hi Carl, Preformed Line Products says: ""Guy-Grip Dead-ends are intended for use on single wood poles associated with distribution construction." If you examine the Rohn tower hardware catalog, they
/archives//html/Topband/2014-09/msg00055.html (12,975 bytes)

158. Re: Topband: Radial Wire (score: 1)
Author: donovanf@starpower.net
Date: Wed, 22 Oct 2014 14:17:06 -0400 (EDT)
iwc2carl on ebay is my favorite supplier of bulk wire. He's very reliable, consistently less expensive (including shipping) than the retail stores and electrical wholesalers, ships in a few days and
/archives//html/Topband/2014-10/msg00106.html (8,150 bytes)

159. Re: Topband: Radial Wire (score: 1)
Author: donovanf@starpower.net
Date: Wed, 22 Oct 2014 22:05:21 -0400 (EDT)
Hi Gary, I've used bare 14 AWG solid bare copper wire with good success in shallow buried radial systems. It would be a poor choice in corrosive soil (my heavy clay soil is not corrosive). I use 16 A
/archives//html/Topband/2014-10/msg00120.html (11,361 bytes)

160. Re: Topband: Beverage antenna in woods. (score: 1)
Author: donovanf@starpower.net
Date: Wed, 5 Nov 2014 10:48:05 -0500 (EST)
Hi Bruce, My temporary 8-circle vertical array re-installed every fall/winter season on a borrowed 4 acre farm field 1200 feet south of the full size transmit 4-square provides lots of exercise too!
/archives//html/Topband/2014-11/msg00017.html (7,856 bytes)


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