Topband: Antenna analysers in close proximity to BC station
That's an interesting idea Red and worth a try. 73 Tom G3OLB WO0W wrote: Perhaps you can take a portable transmitter and manual tuner to the site. At the point where you wish to place an L network, attach the manual tuner and transmitter and adjust the tuner for a good match. Take the tuner away from the source of interference, put a 50 Ohm dummy load on the tuner input, and measure the impedance on the tuner output with the MFJ-259B. I believe that should be close to the value of the impedance of the antenna that was measured, with little or no affect from the strong broadcast signal. ___ Topband reflector - topband@contesting.com
Topband: PT0S DXpedition
G'Day Topbanders, The PT0S DXpedition is scheduled to sail for St. Peter and St. Paul Rocks the evening of Nov 05 (maybe early Nov 06 because of weather). We expect to arrive on the rocks the morning of Nov 09. The first to go up will be the 160 m station, which we hope to get on the air that evening. Our plan is to TX somewhere around 1816.5 kHz and listen up 2 to 5 for EU/NA, and between 1822 and 1825 for JA-s. PT0S will be very challanging for JA-s (and other Asian stations) on 160. They will have to work through a very long path, close to the Auroral region, and over (really, under) much stronger EU signals. To give the JA-s a chance, EU and NA stations please do not call us between 1822 and 1825. Your consideration will be much appreciated. We will be located on the main rock, called Belmonte, where we expect very high levels of local noise from the various scientific equipment. We are planning to build two remote RX antennas on one of the remote rocks (called Cabral) and run the coax and control cables under water. These RX antennas should be up by the 11th or 12th of November. We hope they will improve our ability to copy weak signals. For additional information and updates please visit http://pt0s.com/ GL and 73, George, AA7JV ___ Topband reflector - topband@contesting.com
Topband: PT0S DXpedition
G'Day Topbanders, The PT0S DXpedition is scheduled to sail for St. Peter and St. Paul Rocks the evening of Nov 05 (maybe early Nov 06 because of weather). We expect to arrive on the rocks the morning of Nov 09. The first to go up will be the 160 m station, which we hope to get on the air that evening. Our plan is to TX somewhere around 1816.5 kHz and listen up 2 to 5 for EU/NA, and between 1822 and 1825 for JA-s. PT0S will be very challanging for JA-s (and other Asian stations) on 160. They will have to work through a very long path, close to the Auroral region, and over (really, under) much stronger EU signals. To give the JA-s a chance, EU and NA stations please do not call us between 1822 and 1825. Your consideration will be much appreciated. We will be located on the main rock, called Belmonte, where we expect very high levels of local noise from the various scientific equipment. We are planning to build two remote RX antennas on one of the remote rocks (called Cabral) and run the coax and control cables under water. These RX antennas should be up by the 11th or 12th of November. We hope they will improve our ability to copy weak signals. For additional information and updates please visit http://pt0s.com/ GL and 73, George, AA7JV ___ Topband reflector - topband@contesting.com
Re: Topband: PT0S DXpedition
Excellent approach George! Have a safe trip! Regards, Nodir Tursoon-Zadeh EY8MM http://www.ey8mm.com/ - Original Message - From: GeorgeWallner aa...@atlanticbb.net To: topband@contesting.com Cc: py...@50mhz.com Sent: Monday, November 05, 2012 5:05 AM Subject: Topband: PT0S DXpedition G'Day Topbanders, The PT0S DXpedition is scheduled to sail for St. Peter and St. Paul Rocks the evening of Nov 05 (maybe early Nov 06 because of weather). We expect to arrive on the rocks the morning of Nov 09. The first to go up will be the 160 m station, which we hope to get on the air that evening. Our plan is to TX somewhere around 1816.5 kHz and listen up 2 to 5 for EU/NA, and between 1822 and 1825 for JA-s. PT0S will be very challanging for JA-s (and other Asian stations) on 160. They will have to work through a very long path, close to the Auroral region, and over (really, under) much stronger EU signals. To give the JA-s a chance, EU and NA stations please do not call us between 1822 and 1825. Your consideration will be much appreciated. We will be located on the main rock, called Belmonte, where we expect very high levels of local noise from the various scientific equipment. We are planning to build two remote RX antennas on one of the remote rocks (called Cabral) and run the coax and control cables under water. These RX antennas should be up by the 11th or 12th of November. We hope they will improve our ability to copy weak signals. For additional information and updates please visit http://pt0s.com/ GL and 73, George, AA7JV ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Topband: Antenna analysers in close proximity to BC station
Thinking again about this, we have missed out a stage. After measuring the tuner output impedance, we need to make a temporary L network which, when terminated with 50 ohms, looks like the antenna. Now put the MFJ on this terminated network and measure it's R +/- jX values which will represent the antenna. 73 Tom G3OLB WO0W wrote: Perhaps you can take a portable transmitter and manual tuner to the site. At the point where you wish to place an L network, attach the manual tuner and transmitter and adjust the tuner for a good match. Take the tuner away from the source of interference, put a 50 Ohm dummy load on the tuner input, and measure the impedance on the tuner output with the MFJ-259B. I believe that should be close to the value of the impedance of the antenna that was measured, with little or no affect from the strong broadcast signal. ___ Topband reflector - topband@contesting.com
