Topband: BOG talk
Have had inquires about self termination of BOG antennas. *It varies with the type of soil, moisture content, and length of the wire relative to the ground. Question #1 My BOG is directional, in the direction of the wire without a resistor, then why bother with one? Good Question- Unless you are lucky the terminating resistance and reactance will be less than ideal. * I would rather have a 200 foot BOG with a 200 to 250 ohm termination resistor at the far end for 160 meters. Two 470 ohm resistors in parallel equals 235 ohms and works well.. 75 ohm coax users can transform to 225 ohms with a x 3 turns transformer ratio. 50 ohm coax users can transform to 250 ohms with a x 5 turn transformer ratio.. Question #2 I can understand why some want an incognito antenna, but I have above ground Beverages, why would I want a BOG ? * Well I have above ground Beverages too, but there are times the BOG out shines other antennas, like with QRN when a storm front is approaching. Not sure why, maybe angle of radiation , but 'what ever Beverage antennas do' in this case the BOG often does it better.. In general the BOG is not as good as a Long Beverage antenna, but every antenna has its day. 73 Bruce-K1FZ www.qsl.net/k1fz/bogantennanotes/index.html _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: BOG talk
Wished I had some eggnog. May get some. Meant to type impedance ratio. Thanks for correction ! . 73 'Bruce On Wed, 24 Dec 2014 10:25:39 -0500, kd9sv kd...@comcast.net wrote: Bruce, you been in the eggnog too early...you are giving impedance transformation ratios and not winding ratios...de gary, kd9sv -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of k...@myfairpoint.net Sent: Wednesday, December 24, 2014 10:13 AM To: Topband Subject: Topband: BOG talk Have had inquires about self termination of BOG antennas. *It varies with the type of soil, moisture content, and length of the wire relative to the ground. Question #1 My BOG is directional, in the direction of the wire without a resistor, then why bother with one? Good Question- Unless you are lucky the terminating resistance and reactance will be less than ideal. * I would rather have a 200 foot BOG with a 200 to 250 ohm termination resistor at the far end for 160 meters. Two 470 ohm resistors in parallel equals 235 ohms and works well.. 75 ohm coax users can transform to 225 ohms with a x 3 turns transformer ratio. 50 ohm coax users can transform to 250 ohms with a x 5 turn transformer ratio.. Question #2 I can understand why some want an incognito antenna, but I have above ground Beverages, why would I want a BOG ? * Well I have above ground Beverages too, but there are times the BOG out shines other antennas, like with QRN when a storm front is approaching. Not sure why, maybe angle of radiation , but 'what ever Beverage antennas do' in this case the BOG often does it better.. In general the BOG is not as good as a Long Beverage antenna, but every antenna has its day. 73 Bruce-K1FZ www.qsl.net/k1fz/bogantennanotes/index.html _ Topband Reflector Archives - http://www.contesting.com/_topband This email has been checked for viruses by Avast antivirus software. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: 160m Sloping Vertical Antenna?
Trying to figure out how to best utilize my 106' tower for 160m. The tower sits on a small hill so the downside of the tower is sloping. If I hang a wire off the top, I can bring the other end to the ground and feed it at the bottom. I can ran numerous radials from there. This arrangement can accommodate a quarter wave length. The angle of the tower would be about 20 degrees. Any objections to this plan? Open to other ideas. Thanks in advance and happy holidays! Ed NI6S _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160m Sloping Vertical Antenna?
On Wed,12/24/2014 10:29 AM, Ed via Topband wrote: Trying to figure out how to best utilize my 106' tower for 160m. The tower sits on a small hill so the downside of the tower is sloping. If I hang a wire off the top, I can bring the other end to the ground and feed it at the bottom. I can ran numerous radials from there. That's exactly what I'm doing -- my tower is 115 ft with roughly 7 ft of mast above it and a 3-el SteppIR. I have sloping wires on two opposite sides, supported from the tower just below the rotator with a 10 ft section of 4-in PVC conduit. Each wire has its own set of 4 radials elevated about 18 ft. The tower, which is grounded, has a dozen or so radials laying on the ground. With this configuration, the tower will act as a reflector, yielding about 6 dB front to back. How much GAIN you get will depend on your radial system and the quality of your soil. I started with radials elevated only a few feet, and gain was poor. On the advice of N6BT, I raised them and gain improved. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160m Sloping Vertical Antenna?
I used to use a similar method on 80 meters. Why not feed it (them) at the top? Jim - KR9U -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Wednesday, December 24, 2014 1:46 PM To: topband@contesting.com Subject: Re: Topband: 160m Sloping Vertical Antenna? On Wed,12/24/2014 10:29 AM, Ed via Topband wrote: Trying to figure out how to best utilize my 106' tower for 160m. The tower sits on a small hill so the downside of the tower is sloping. If I hang a wire off the top, I can bring the other end to the ground and feed it at the bottom. I can ran numerous radials from there. That's exactly what I'm doing -- my tower is 115 ft with roughly 7 ft of mast above it and a 3-el SteppIR. I have sloping wires on two opposite sides, supported from the tower just below the rotator with a 10 ft section of 4-in PVC conduit. Each wire has its own set of 4 radials elevated about 18 ft. The tower, which is grounded, has a dozen or so radials laying on the ground. With this configuration, the tower will act as a reflector, yielding about 6 dB front to back. How much GAIN you get will depend on your radial system and the quality of your soil. I started with radials elevated only a few feet, and gain was poor. On the advice of N6BT, I raised them and gain improved. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160m Sloping Vertical Antenna?
Do a sloper (half WL) and feed in the center. Half of one of the half go to the other side, like an inverted V 73, Jorge CX6VM/CW5W Enviado desde mi iPhone El 24/12/2014, a las 17:10, James Wolf jbw...@comcast.net escribió: I used to use a similar method on 80 meters. Why not feed it (them) at the top? Jim - KR9U -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Wednesday, December 24, 2014 1:46 PM To: topband@contesting.com Subject: Re: Topband: 160m Sloping Vertical Antenna? On Wed,12/24/2014 10:29 AM, Ed via Topband wrote: Trying to figure out how to best utilize my 106' tower for 160m. The tower sits on a small hill so the downside of the tower is sloping. If I hang a wire off the top, I can bring the other end to the ground and feed it at the bottom. I can ran numerous radials from there. That's exactly what I'm doing -- my tower is 115 ft with roughly 7 ft of mast above it and a 3-el SteppIR. I have sloping wires on two opposite sides, supported from the tower just below the rotator with a 10 ft section of 4-in PVC conduit. Each wire has its own set of 4 radials elevated about 18 ft. The tower, which is grounded, has a dozen or so radials laying on the ground. With this configuration, the tower will act as a reflector, yielding about 6 dB front to back. How much GAIN you get will depend on your radial system and the quality of your soil. I started with radials elevated only a few feet, and gain was poor. On the advice of N6BT, I raised them and gain improved. 73, Jim K9YC _ 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: 160m Sloping Vertical Antenna?
On Wed,12/24/2014 1:05 PM, Jorge Diez CX6VM wrote: Half of one of the half go to the other side, like an inverted V That would be a pretty low dipole on 160M, and verticals tend to be far more effective on 160M than low dipoles. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160m Sloping Vertical Antenna?
On the thought of a low dipole: Years ago in Northern California, as an experiment, I had a VERY low dipole and got some strange results. Listening to a local station, in the afternoon, there was very deep QSB. We were able to talk, but with difficulty. 73, Art W5AER On 12/24/2014 4:53 PM, Jim Brown wrote: On Wed,12/24/2014 1:05 PM, Jorge Diez CX6VM wrote: Half of one of the half go to the other side, like an inverted V That would be a pretty low dipole on 160M, and verticals tend to be far more effective on 160M than low dipoles. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160m Sloping Vertical Antenna?
On 12/24/2014 3:39 PM, Art Roberts - W5AER wrote: On the thought of a low dipole: Years ago in Northern California, as an experiment, I had a VERY low dipole and got some strange results. Listening to a local station, in the afternoon, there was very deep QSB. We were able to talk, but with difficulty. 73, Art W5AER Were you cross polarized; IE was the other station running a vertical? If so, minor fluctuations in propagation could result in major fluctations of polarization cancellation. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160m Sloping Vertical Antenna?
Jorge, I have a 160m antenna asymmetrical antenna, fed against ground, that goes from one corner of my 120 ft by 120 ft lot to the opposite corner. It is held up by a single pole, about 55 ft tall. The pole is closer to the fed end. The wire going up to the pole makes about a 65 degree angle above the horizontal; the wire going down to the opposite corner makes an angle of about 25 degrees below the horizontal (the angles are estimated by eye-they definitely have not been measured). The far end is about 10 ft off the ground. In other words an inverted L where the vertical part is not vertical and the horizontal part is not horizontal. The length is the length arrived at by many trials and errors that, with a matching capacitor between the antenna and one inch hardline coax feeder, yielded an SWR of approximately 1:1 at 1825 mHz. I also use this antenna on 80 m through 10 m by using an antenna tuner in the shack. My radials are about one inch deep in the ground and restricted to one quadrant. They vary in length from 100 ft (along the north and east fence lines) down to 35 ft (house in the way). Number of radials is probably about 20 (I really don't remember). QTH is SE NM. Maximum power is 500 watts. I have 190 countries confirmed on160 m. I have no idea of the pattern of the 160 m antenna. I am guessing that it works as well as it does because the maximum radiation occurs well above ground (and the ground around its feed point is very cluttered by power lines, houses, trees) and is not straight up (like a low inverted dipole). 73 Paul W5DM _ Topband Reflector Archives - http://www.contesting.com/_topband
