Re: Topband: ZS6BKW
I'm sure interested in your PP presentation. I know a highly competitive CW and RTTY contester who uses a W8AMZ 160M Reduced 1/2 Sloper and a Shielded Magnetic Receive-Only Loop Antenna and does much better on 160M than might be expected. 73, Marsh, KA5M ma...@ka5m.net -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James Rodenkirch Sent: Saturday, March 28, 2015 4:47 PM To: 'Mike Smith VE9AA'; Top Band Contesting Subject: Re: Topband: ZS6BKW That W8AMZ sloper is a condensed version of this antenna: http://www.iw5edi.com/ham-radio/?a-160-meter-antenna-for-small-lot,105 W8AMZ's loading coil (that black thingy between the SO-239 and the 68' feet of black wire) is sort of how I constructed my 160 meter antenna for a small lot. I wound the 70' vertical coil into a condensed 4.5 feet of coil at the top of the 8' PVC.used about five or six 50' to 70' radials lying on top of the groundhad 180+ QSOs in the 2010 and 2011 CQ 160 contests as a QRP entry including JAs and KHs Best of luck, MikeI have a Power Point wiring schema for my antenna if interested72, Jim Rodenkirch K9JWV From: ma...@ka5m.net To: ve...@nbnet.nb.ca; topband@contesting.com Date: Sat, 28 Mar 2015 15:58:21 -0500 Subject: Re: Topband: ZS6BKW Mike, I found a website with detailed info on the ZS6BKW antenna. http://www.nc4fb.org/wordpress/zs6bkw-multi-band-antenna/ To use the antenna on 80M and above the 39.1 ft of ladderline should drop down as vertically as possible, and then connect to 50 ohm coax through a 1:1 current balun (common mode choke). If you connect the station end of the coax shield to center conductor and feed it against a radial system the coax will be part of the vertical element of what has become a 160M top loaded vertical fed against a radial system. How will the coax in your installation run from the station to the base of the ladderline? Or, if you have a 40 - 45 ft high support (tree) you might consider a W8AMZ 160M Reduced 1/2 Sloper. http://w8amz.com/W8AMZ_SLOPERS_Page.html If you do try the ZS6BKW antenna reconfigured as a top loaded vertical on 160M by connecting the station end of the coax shield to center conductor fed against a radial system, I'd like to know how it works for you. 73, Marsh, KA5M -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Mike Smith VE9AA Sent: Saturday, March 28, 2015 1:44 PM To: topband@contesting.com Subject: Topband: ZS6BKW Thanks very much Marsh. Obviously you have some serious antenna modeling skills and I do thank you for that second analysis. If I may indulge you for one last request (tweak) pse? If you could keep everything the same, but instead, leave the ladder line as is and short the 50' of coax at the shack end (and add a normal 10' jumper to the radio if it makes a difference?) would that make the #'s much different? Ground radials attached to the real 10' jumper /shorted coax interface, right at the window. I think in actuality I am going to buy LM240 (is that that right moniker for a RG8/x mini equivalent?) so I can sneak it out a window, etc. and if I was able to make the switch-over in the shack (or right at the window-ledge) then that would be the way I go. Thanks for the extra work. Hope we manage a QSO ! Mike VE9AA ??#??? this summer. p.s.-can't wait for snowmelt as I can start building and testing ! Mike, Coreen Corey Keswick Ridge, NB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: BCB Inv L
Sure is - Randall Mullinax, AD5RM. 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. On 3/27/2015 11:12 PM, Art Snapper wrote: The radio station engineer in Moore, OK tuned a broken tower to get the station back on the air. It reminds me of an inverted L. Perhaps he is a ham. *http://tinyurl.com/qh8rxmz http://tinyurl.com/qh8rxmz* _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: ZS6BKW
Mike, I found a website with detailed info on the ZS6BKW antenna. http://www.nc4fb.org/wordpress/zs6bkw-multi-band-antenna/ To use the antenna on 80M and above the 39.1 ft of ladderline should drop down as vertically as possible, and then connect to 50 ohm coax through a 1:1 current balun (common mode choke). If you connect the station end of the coax shield to center conductor and feed it against a radial system the coax will be part of the vertical element of what has become a 160M top loaded vertical fed against a radial system. How will the coax in your installation run from the station to the base of the ladderline? Or, if you have a 40 - 45 ft high support (tree) you might consider a W8AMZ 160M Reduced 1/2 Sloper. http://w8amz.com/W8AMZ_SLOPERS_Page.html If you do try the ZS6BKW antenna reconfigured as a top loaded vertical on 160M by connecting the station end of the coax shield to center conductor fed against a radial system, I'd like to know how it works for you. 73, Marsh, KA5M -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Mike Smith VE9AA Sent: Saturday, March 28, 2015 1:44 PM To: topband@contesting.com Subject: Topband: ZS6BKW Thanks very much Marsh. Obviously you have some serious antenna modeling skills and I do thank you for that second analysis. If I may indulge you for one last request (tweak) pse? If you could keep everything the same, but instead, leave the ladder line as is and short the 50' of coax at the shack end (and add a normal 10' jumper to the radio if it makes a difference?) would that make the #'s much different? Ground radials attached to the real 10' jumper /shorted coax interface, right at the window. I think in actuality I am going to buy LM240 (is that that right moniker for a RG8/x mini equivalent?) so I can sneak it out a window, etc. and if I was able to make the switch-over in the shack (or right at the window-ledge) then that would be the way I go. Thanks for the extra work. Hope we manage a QSO ! Mike VE9AA ??#??? this summer. p.s.-can't wait for snowmelt as I can start building and testing ! Mike, Coreen Corey Keswick Ridge, NB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: ZS6BKW
That W8AMZ sloper is a condensed version of this antenna: http://www.iw5edi.com/ham-radio/?a-160-meter-antenna-for-small-lot,105 W8AMZ's loading coil (that black thingy between the SO-239 and the 68' feet of black wire) is sort of how I constructed my 160 meter antenna for a small lot. I wound the 70' vertical coil into a condensed 4.5 feet of coil at the top of the 8' PVC.used about five or six 50' to 70' radials lying on top of the groundhad 180+ QSOs in the 2010 and 2011 CQ 160 contests as a QRP entry including JAs and KHs Best of luck, MikeI have a Power Point wiring schema for my antenna if interested72, Jim Rodenkirch K9JWV From: ma...@ka5m.net To: ve...@nbnet.nb.ca; topband@contesting.com Date: Sat, 28 Mar 2015 15:58:21 -0500 Subject: Re: Topband: ZS6BKW Mike, I found a website with detailed info on the ZS6BKW antenna. http://www.nc4fb.org/wordpress/zs6bkw-multi-band-antenna/ To use the antenna on 80M and above the 39.1 ft of ladderline should drop down as vertically as possible, and then connect to 50 ohm coax through a 1:1 current balun (common mode choke). If you connect the station end of the coax shield to center conductor and feed it against a radial system the coax will be part of the vertical element of what has become a 160M top loaded vertical fed against a radial system. How will the coax in your installation run from the station to the base of the ladderline? Or, if you have a 40 - 45 ft high support (tree) you might consider a W8AMZ 160M Reduced 1/2 Sloper. http://w8amz.com/W8AMZ_SLOPERS_Page.html If you do try the ZS6BKW antenna reconfigured as a top loaded vertical on 160M by connecting the station end of the coax shield to center conductor fed against a radial system, I'd like to know how it works for you. 73, Marsh, KA5M -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Mike Smith VE9AA Sent: Saturday, March 28, 2015 1:44 PM To: topband@contesting.com Subject: Topband: ZS6BKW Thanks very much Marsh. Obviously you have some serious antenna modeling skills and I do thank you for that second analysis. If I may indulge you for one last request (tweak) pse? If you could keep everything the same, but instead, leave the ladder line as is and short the 50' of coax at the shack end (and add a normal 10' jumper to the radio if it makes a difference?) would that make the #'s much different? Ground radials attached to the real 10' jumper /shorted coax interface, right at the window. I think in actuality I am going to buy LM240 (is that that right moniker for a RG8/x mini equivalent?) so I can sneak it out a window, etc. and if I was able to make the switch-over in the shack (or right at the window-ledge) then that would be the way I go. Thanks for the extra work. Hope we manage a QSO ! Mike VE9AA ??#??? this summer. p.s.-can't wait for snowmelt as I can start building and testing ! Mike, Coreen Corey Keswick Ridge, NB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: BLE: Dense vs. Sparse Buried Radials
Conclusions from graphics of the Brown, Lewis Epstein ground systems experiments (linked below)... - When relatively few buried radials are used, there is little improvement in the GW E-field radiated by monopoles with a physical height of 77 degrees or longer when those radials exceed about 50 degrees in length (a free-space physical length of 0.137 lambda). - The greatest GW field at 0.3 miles downrange radiated when using 15 x 0.412-lambda buried radials is about 1.9 dB below the theoretical value for a perfect monopole of that height driven against a perfect ground plane (other things equal). - When 113 (or more) radials of 0.412 lambda are used, the greatest radiated field is about 0.22 dB below the theoretical value. This corresponds to an increase in radiated power of about 47% compared to using only 15 radials of 0.412 lambda. - The field when using 15 radials of 0.137 lambda each is within 0.3 dB of that when using 113 radials of 0.137 lambda each (other things equal). The increase in radiated power when using 113 rather than 15 radials of 0.137 lambda has dropped to about 7%. These field improvements also affect spacewave/skywave radiation, as the improvements are based on the power radiated (launched) by a vertical monopole at all elevation angles below the zenith. Therefore these findings have value for ham radio operators, even though hams usually are not too concerned about groundwave radiation. Here is a relevant quote from pp. 773-774 of the BLE paper (the 45 foot radial length corresponds to 0.137 lambda at the 3 MHz test frequency): \\ When the radial wires were 45 feet long, the measured resistance was practically independent of the number of wires. Evidently, most of the earth loss occurred in regions beyond the periphery of the ground system. // http://s17.postimg.org/agcdab9jz/BL_E_Figs_38_39.jpg R. Fry, CPBE _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: ZS6BKW
Thanks very much Marsh. Obviously you have some serious antenna modeling skills and I do thank you for that second analysis. If I may indulge you for one last request (tweak) pse? If you could keep everything the same, but instead, leave the ladder line as is and short the 50' of coax at the shack end (and add a normal 10' jumper to the radio if it makes a difference?) would that make the #'s much different? Ground radials attached to the real 10' jumper /shorted coax interface, right at the window. I think in actuality I am going to buy LM240 (is that that right moniker for a RG8/x mini equivalent?) so I can sneak it out a window, etc. and if I was able to make the switch-over in the shack (or right at the window-ledge) then that would be the way I go. Thanks for the extra work. Hope we manage a QSO ! Mike VE9AA ??#??? this summer. p.s.-can't wait for snowmelt as I can start building and testing ! Mike, Coreen Corey Keswick Ridge, NB Mike, Coreen Corey Keswick Ridge, NB _ Topband Reflector Archives - http://www.contesting.com/_topband
