Regarding backscatter on a yagi, I have always heard that it is a great way of picking up and finding those weak signal/QRP stations that may not be heard off the front end of the antenna.
Hi David , Is there any way I can entice you to give 4nec2 a fair shake ? I've been playing with 4nec2 for about 5 years now I think it is the superior program. It is almost like being able to see into the radio spectrum. I went completely overboard when I found out I could figure it out and use it to answer most the questions others argued about. You can use variables in the wire geometry and even use trig functions to describe the wires. The optimizer has a sweep function that lets you to really easily do the type of height test I saw in video #100 . Once the model is built it would only take a couple of minutes to have it run every height from 5 feet to 100 feet in as many steps as you want. Just hitting the arrow buttons scrolls through the different patterns. I also have ground planes that the radials can be swept from about 80degrees (almost a sleeve antenna) to about -80 (almost a dipole) It's cool to watch the specs as the radials drop one or 2 degrees at a time , it even graphs the results in case you missed the trends. Does EZnec do vertical vs horizontal polarization? Circular polarization? Axial ratio? There is no limit on the number of segments and the format of the models files are text files allowing easier sharing and collaboration. Oh and it runs in linux using wine . I was wondering about the vertical vs horizontal because the dipole you show at ~ @19:13 virtually all the radiation going north and south is vertical polarized even though the dipole is horizontal. That would farther attenuate the signal due to mismatch. In the horizontal polarized pattern the north and south have deep nulls. I also think that there is value in modeling in free space especially if you are designing an antenna, and also as the frequency goes into UHF and above. Not to mention the simple curiosity factor of seeing what the pattern looks like with nothing around at all you quench by looking at the free space pattern. Including a ground during development can also interfere with the optimization. Putting it above ground is the last thing I do when studying a model I've made. One issue I always found with ground is which should you use? One group of collaborators I was involved with finally decided to just use free space to keep the variations in the types of grounds from influencing the designs. After all we were trying for a design that works best regardless of what ground they use it over (this was TV frequencies). Another group could not escape using some ground as they were playing with 10-12 meter antennas and the ground is inescapable (we never came to a consensus). I did quite a lot of experiments with the various grounds available and became completely confused. Using even standard types of antennas over various grounds the "good ground " had less gain than the "poor ground" even the take off angle was better (lower) over poor ground IIRC. My avatar is a circular polarized omni I have played with way to much. 73's
Hi Dave, love watching your videos, been binge watching as I've been ill the last week and it's been great seeing your passion and knowledge for the subject transpose to your excellent teaching style. However, just a slight cultural correction for you. The 'oggie' is a slang term for a Cornish pastry. The Scottish pastry is called a Bridie (pronounced bride'ee as in groom and bride, if you're from the central belt of Scotland) or 'bradie' (as in brad'ee the name brad, if you're from the North East Scotland), depending on your regional dialect in Scotland
Hi Dave, Could you shed some light on something I've been thinking about trying. I would like to know if you think a Double Bazooka Antenna, (K3DAV type) would work as an inverted V antenna. Thanks, Pete.
BrooklandBackyardBrewery Pete I used run a 40 meter Double Bazooka in an inverted V configuration. The apex was about 40 feet high with the ends about 20 feet high. It worked extremely well. The DX was fantastic and it was pretty quiet. Of all of the antennas I've run to date, the Double Bazooka was my most favorite, best performing antenna.
Definitely in as an OGGIE!. . . and as an Bridie . . . and as a Bradie (thank you, Mr. Gordon). So, if we combine them, we’re Oggadies (oddities, get it?!) . . .
It is the nickname of a fan of this channel. Dave always has an "og' in the corner of his videos (the last two letters of his call sign), and at the end of this video, he suggested his fans could call themselves "oggies".
Hi, David, question, how Is the actual shipping situation of the big fire in California? our colleagues? here in my region, Valdivia in Chile, a group of organizations , including Red Cross, fire department, Private Protected Areas (native forest), SAR (similar to USAR), the "colegio de ingenieros en recursos naturales", my family protected area, have a campaign for to prevent the fires.... visit our fanpage " yoprevengolosincendios", and soon I will to start to spread our prevention message by our emergency hamradio radio networks. 73's David and I wish the best to all our ham radio and Red Cross (I'm member of the Chilean Red Cross als colleagues too) colleagues...
What we hear in Colorado is that the fires in Southern California are unstoppable because of the hurricane-force winds. I grew up in that area, and have been to several of the places shown on TV. Terrible situation there!
I understand, In Chile we have a huge fire of 1.235.526 acres. In the Verona county in California, 83,000 acres are burning, 1700 fireman’s and police officers, and assume FEMA are fighting the fire... The ARES and RACERS are in service with the emergency?
Regarding backscatter on a yagi, I have always heard that it is a great way of picking up and finding those weak signal/QRP stations that may not be heard off the front end of the antenna.
Great video (again) Dave. Be glad that you have that book. $170 on Amazon and eBay, out of print on the ARRL website.
Hi David ,
Is there any way I can entice you to give 4nec2 a fair shake ?
I've been playing with 4nec2 for about 5 years now I think it is the superior program.
It is almost like being able to see into the radio spectrum. I went completely overboard when I found out I could figure it out and use it to answer most the questions others argued about.
You can use variables in the wire geometry and even use trig functions to describe the wires.
The optimizer has a sweep function that lets you to really easily do the type of height test I saw in video #100 .
Once the model is built it would only take a couple of minutes to have it run every height from 5 feet to 100 feet in as many steps as you want. Just hitting the arrow buttons scrolls through the different patterns.
I also have ground planes that the radials can be swept from about 80degrees (almost a sleeve antenna) to about -80 (almost a dipole) It's cool to watch the specs as the radials drop one or 2 degrees at a time , it even graphs the results in case you missed the trends.
Does EZnec do vertical vs horizontal polarization? Circular polarization? Axial ratio?
There is no limit on the number of segments and the format of the models files are text files allowing easier sharing and collaboration. Oh and it runs in linux using wine .
I was wondering about the vertical vs horizontal because the dipole you show at ~ @19:13
virtually all the radiation going north and south is vertical polarized even though the dipole is horizontal. That would farther attenuate the signal due to mismatch.
In the horizontal polarized pattern the north and south have deep nulls.
I also think that there is value in modeling in free space especially if you are designing an antenna, and also as the frequency goes into UHF and above.
Not to mention the simple curiosity factor of seeing what the pattern looks like with nothing around at all you quench by looking at the free space pattern.
Including a ground during development can also interfere with the optimization.
Putting it above ground is the last thing I do when studying a model I've made.
One issue I always found with ground is which should you use?
One group of collaborators I was involved with finally decided to just use free space to keep the variations in the types of grounds from influencing the designs.
After all we were trying for a design that works best regardless of what ground they use it over (this was TV frequencies).
Another group could not escape using some ground as they were playing with 10-12 meter antennas and the ground is inescapable (we never came to a consensus).
I did quite a lot of experiments with the various grounds available and became completely
confused.
Using even standard types of antennas over various grounds the "good ground " had less gain than the "poor ground" even the take off angle was better (lower) over poor ground IIRC.
My avatar is a circular polarized omni I have played with way to much.
73's
I've been learning about EZNEC+ but haven't given 4nec2 a good try yet.
HAPPY HOLIDAYS! from W9DES 73 Dave
Thanks! And Happy Holidays to all!
Dave, have you seen "An Introduction to Antenna Modeling" from RSGB? Wondering how it compares to the out of print ARRL book that you recommended.
I haven't. I notice there's a new antenna modeling book in the ARRL store, but it's not available for sale yet.
Hi Dave, love watching your videos, been binge watching as I've been ill the last week and it's been great seeing your passion and knowledge for the subject transpose to your excellent teaching style. However, just a slight cultural correction for you. The 'oggie' is a slang term for a Cornish pastry. The Scottish pastry is called a Bridie (pronounced bride'ee as in groom and bride, if you're from the central belt of Scotland) or 'bradie' (as in brad'ee the name brad, if you're from the North East Scotland), depending on your regional dialect in Scotland
Good catch! Thanks!
Awesome Info, 73s
Thank you!
Hi Dave, Could you shed some light on something I've been thinking about trying. I would like to know if you think a Double Bazooka Antenna, (K3DAV type) would work as an inverted V antenna. Thanks, Pete.
I would think so.
BrooklandBackyardBrewery Pete
I used run a 40 meter Double Bazooka in an inverted V configuration. The apex was about 40 feet high with the ends about 20 feet high. It worked extremely well. The DX was fantastic and it was pretty quiet.
Of all of the antennas I've run to date, the Double Bazooka was my most favorite, best performing antenna.
Still don’t understand the orientation of the antenna to the plots?
Antenna points to right (east)
Definitely in as an OGGIE!. . . and as an Bridie . . . and as a Bradie (thank you, Mr. Gordon). So, if we combine them, we’re Oggadies (oddities, get it?!) . . .
:-)
I'm on the game plan, Oggies, Dan KI6VBC
Cool!
Count me as an Oggie!
Hi, what is "oggie"?
It is the nickname of a fan of this channel. Dave always has an "og' in the corner of his videos (the last two letters of his call sign), and at the end of this video, he suggested his fans could call themselves "oggies".
thank you very much Tony for The info... any news from The Ares and racers in The área of The fires?
Oggies oggied full of knowlage
Book out of print and second hand book prices ridiculously over priced.
How about Og're Dave? Good video BTW... HIHI!
Watt
de K4WRF
I'm OK with being a Scottish pastry. Better that than a jelly doughnut like JFK was! :)
greetings from Chile (CE) XQ6WBM
Hello!
Hi, David, question, how Is the actual shipping situation of the big fire in California? our colleagues? here in my region, Valdivia in Chile, a group of organizations , including Red Cross, fire department, Private Protected Areas (native forest), SAR (similar to USAR), the "colegio de ingenieros en recursos naturales", my family protected area, have a campaign for to prevent the fires.... visit our fanpage " yoprevengolosincendios", and soon I will to start to spread our prevention message by our emergency hamradio radio networks. 73's David and I wish the best to all our ham radio and Red Cross (I'm member of the Chilean Red Cross als colleagues too) colleagues...
What we hear in Colorado is that the fires in Southern California are unstoppable because of the hurricane-force winds. I grew up in that area, and have been to several of the places shown on TV. Terrible situation there!
I understand, In Chile we have a huge fire of 1.235.526 acres. In the Verona county in California, 83,000 acres are burning, 1700 fireman’s and police officers, and assume FEMA are fighting the fire...
The ARES and RACERS are in service with the emergency?
I would presume that they are, though official communications in the area is robust.
Oh jeez...
:-)
Oggie hum. Not Ogs, Oh well a Scottish Pastry it is.