Topband: Twinax
I am in the process of building a Waller Flag - I am going to use Twinax - the Twinax I have purchased has a braiding screen similar to coax. What do I connect if anything the coax type screening to? Do I leave it floating or connect it to one of the inner two wires. Sorry if its a sill question but I have never used Twinax before and the construction details explain that Twinax is the best choice for the phasing and connection to the two loops being the most durable in respect of weather and UV. Dave g3rcq _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Twinax
Probably float the shield end at the antenna and ground the the other shield end at the radio. This is the old Faraday shield trick that works at video up to 4 Mhz. The purists say it shouldn't, but i have seen in video hum reduction and RFI it does indeed work. Herb, KV4FZ On 4/7/2015 10:12 AM, David Cole wrote: I am in the process of building a Waller Flag - I am going to use Twinax - the Twinax I have purchased has a braiding screen similar to coax. What do I connect if anything the coax type screening to? Do I leave it floating or connect it to one of the inner two wires. Sorry if its a sill question but I have never used Twinax before and the construction details explain that Twinax is the best choice for the phasing and connection to the two loops being the most durable in respect of weather and UV. Dave g3rcq _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Which 4 directions?
I'm planning to build and deploy 4 receiving antennasfor 160M this summer - some mix of BOGs, K9AYs, etc.Question is, where would you aim them, from a QTH 60 miles NW of Washington DC. My main objective is to finish my 160M DXCC, now hovering at 72 worked. The quantitative constraint is due to the switching system I have in place. -- 73, Pete N4ZR Check out the Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com. For spots, please go to your favorite ARC V6 or VE7CC DX cluster node. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which 4 directions?
Hi Pete, Most entities needed to finish your first 100 entities for DXCC are northeast of you. Your best receiving antenna should be in that direction. The remaining directions in order of importance for achieving your first 100 entities are: South, West and East. Is it possible to install a small array of short verticals at your QTH? Verticals are excellent building blocks for receiving antennas because -- unlike loops-- they naturally have a broad deep null at high angles. A 160 meter receiving 4-square can be built with verticals as short as 20 feet and can be built with 80 foot sides, or even smaller. 73 Frank W3LPL - Original Message - From: Pete Smith N4ZR n...@contesting.com To: topband reflector Topband@contesting.com Sent: Tuesday, April 7, 2015 4:51:55 PM Subject: Topband: Which 4 directions? I'm planning to build and deploy 4 receiving antennasfor 160M this summer - some mix of BOGs, K9AYs, etc.Question is, where would you aim them, from a QTH 60 miles NW of Washington DC. My main objective is to finish my 160M DXCC, now hovering at 72 worked. The quantitative constraint is due to the switching system I have in place. -- 73, Pete N4ZR Check out the Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com. For spots, please go to your favorite ARC V6 or VE7CC DX cluster node. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which 4 directions?
On Tue,4/7/2015 9:51 AM, Pete Smith N4ZR wrote: I'm planning to build and deploy 4 receiving antennasfor 160M this summer - some mix of BOGs, K9AYs, etc.Question is, where would you aim them, from a QTH 60 miles NW of Washington DC. I would look at your 160M DXCC list, see what you've worked and what you're missing. When I moved here, I put together a spreadsheet of the headings of NA cities (for contesting purposes) and DX countries. I included distances, then sorted by azimuth. Next, I drew a plan view of the clearing around my house and ham shack showing the dozen or so trees that looked like suitable supports work wire antennas. Based on that study, I figured out that I needed a dipole broadside to about 50 degrees to work the east coast, EU, and VK/ZL, and a second one broadside to about 310 degrees to work Asia and South America. I laid out two reversible Beverages using DX Engineering hardware with the same headings. I had ACAD on my biz computer, and used that to generate and maintain the drawings. My property is not very friendly to the vertical RX arrays that Frank suggested. BUT -- I strongly recommend that you chase down the presentation on RX antennas that he did last year for Contest University at Dayton. In it, he observed that some array types are more tolerant of nearby objects than others. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which 4 directions?
Pete, It helps to know the 3 dB beamwidth of your antennas. Since mine (580' 2-wire Beverages) are about 90 degrees, I chose NE, SE, SW, and NW. I think your headings will be similar. Check out: www.w0btu.com/Beverage_antennas.html#Misc_Beverage_antenna_notes and www.w0btu.com/links.html#Azimuthal_maps . DX Atlas is invaluable for calculating this. 73, Mike www.w0btu.com On Tue, Apr 7, 2015 at 2:03 PM, Mike Waters mikew...@gmail.com wrote: Pete, It helps to know the 3 dB beamwidth of your antennas. Since mine are about 90 degrees, I chose NE, SE, SW, and NW. I think your heading will be similar. Check out On Tue, Apr 7, 2015 at 11:51 AM, Pete Smith N4ZR n...@contesting.com wrote: I'm planning to build and deploy 4 receiving antennasfor 160M this summer - some mix of BOGs, K9AYs, etc.Question is, where would you aim them, from a QTH 60 miles NW of Washington DC. My main objective is to finish my 160M DXCC, now hovering at 72 worked. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which 4 directions?
Well Pete, the first 200 is the easy part. I would look at where you are most likely to work new ones, which in your case would be South and EU. I currently have 299 confirmed and my (now) preferred directions would be North Over the Pole for anything in the Pacific and South right through Africa. Just because the remaining Countries with the exception of P5 and BS7H are in those directions . So I suggest you plan along those lines. 73 Clive GM3POI -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Pete Smith N4ZR Sent: 07 April 2015 16:52 To: topband reflector Subject: Topband: Which 4 directions? I'm planning to build and deploy 4 receiving antennasfor 160M this summer - some mix of BOGs, K9AYs, etc.Question is, where would you aim them, from a QTH 60 miles NW of Washington DC. My main objective is to finish my 160M DXCC, now hovering at 72 worked. The quantitative constraint is due to the switching system I have in place. -- 73, Pete N4ZR Check out the Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com. For spots, please go to your favorite ARC V6 or VE7CC DX cluster node. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which 4 directions?
On Tue,4/7/2015 12:07 PM, Mike Waters wrote: DX Atlas is invaluable for calculating this. Yes. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which 4 directions?
Frank wrote: A 160 meter receiving 4-square can be built with verticals as short as 20 feet and can be built with 80 foot sides, or even smaller. Azimuth and elevation patterns for a few typical arrays can be found in the last section on this page: http://ac6la.com/aecollection6.html At the bottom of that section you'll also find various reference links, including Frank's 2014 Contest Univesity presentation that Jim just mentioned. Dan, AC6LA _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which 4 directions?
Mike Waters wrote: If anyone has patterns for those, that would be interesting. I haven't yet written a typical AC6LA more words than any human should be forced to read at one time example, but this post to the Shared Apex Loop Array Yahoo group shows some pattern comparisons: https://groups.yahoo.com/neo/groups/sharedapexloop/conversations/messages/568 Dan, AC6LA _ Topband Reflector Archives - http://www.contesting.com/_topband
