Great Video, should call it the Ukraine Trident Antenna At 11:40 a close up of the Trident feed point, I guess there must be an electrical break in the centre element separating the coax connections. The bulky looking coax at the feed point is, that for matching or choking, if so how is it achieved? Thanks Greg
Making the antenna modeling files available files would be really helpful! In addition, 6 meter and 10 meter versions of the w-pole forker would be amazing! Thank you and 73, K1QS.
I will provide some antenna files although a more comprehensive list of data and antenna files will be available to community members. a 6m Forker is already done. I will cover this and share. I will produce one for 10m too.
Yet another excellent video partly delving into my areas of inquiry. I was hoping for more information on construction materials, wind and ice loading levels, max voltage along each element and between elements, perturbation caused by material choices, why not put another W-pole above with separate feedline, how to adjust phase without increased impedance (e.g. to increase downward gain from a mountain-peak antenna), how to achieve multiple resonance frequencies (e.g. repeater Rx and Tx frequencies). Of course, some of the above can be explored through use of the published models. One thing I hope is in my inexpensive/DIY future is a 2m + 1.25m + 70cm single feed car roof antenna I can hook to a tri-band mobile transceiver, TBD. As well as a higher gain separate vertical VHF/UHF antenna that will allow my HT's to reliably reach Puget Sound repeaters through the temperate rainforest vegetation that absorbs SiriusXM before it reaches my my car.
Thanks for the message Larry - the questions you ask would detract from core intent which is to simply antenna design and understanding for the masses. it maybe later down the line we do some drill down in some areas if there are specific requirements or interest.
I built a 2-armed cactus j pole, with one arm stacked over the other onopposite sides of tbe mast. I used 1/2" copper plumbing pipe. I feed the top arm as usual, and use the bottom as counterpoise and matching element. I included a 1/2 to 3/4" tee, with the 3/4 out the bottom with another root of pipe. I hard mount it to a mast, so it IS GROUNDED! It works great! The purpose of the !ower element is to block the RF from a DC connection to allow for this mount to a mast with DC and RF isolation and provide for lightning protection. I would love to see your take on this variation. Pix and specs available, should you like to see them. 73, WA4KBT
Really enjoying the channel, and the 50 meg yagi was very timely as I'm just getting into VHF DX. I'm also thinking about a 10m J-pole as well... How do you tell what choking impedance you actually need based on the antenna design?
Ideally you can model and simulate into such tome as there is no difference between no connection to ground or a direct connection with a choke. If you watch the Balun videos, I have a very useful tip for being able to establish common mode currents without the need for expensive equipment or simulation.
Good informative video. I made many 2M J-pole antennas (25+) using 1/4-in aluminum rods with these dimensions: 58-in from gnd 18.5-in radiating element 2-in spacing Fed 2-in above gnd Mounted in block of aluminum. Edit add DE KK5R
Thanks for the excellent video, I learnt a lot from it. So many rigs are dual-band, I'm sure I won't be the only one to ask if a dual-band 70cm/2m version would be possible in the future.
I have a dual band 2m and 70cms vertical in the plan that is coming soon. I am still testing it but it is far lower profile than the J-pole. keep an eye on the channel
Great Videos and extremely informative. I would be very interested in a dual band fixed antenna for the SatNogs and Cubesat side of the hobby. If that’s something you could model and make a video on. Thanks.
Can I suggest that you put the support pole in the model as well. In EZNEC simulations I've done it's made a profound difference. The induced current in the pole can be as high as 1/3 of the feedpoint current and this seriously effects the radiation pattern. Even if you use a fibreglass pole, the outer of the coax will pick up in the same way. Making the pole a non-resonant length doesn't work - the induced standing wave is weird. Grounding the pole changes the situation but without significant benefit. This applies even when the antenna is insulated from the pole. Because the pole and the antenna are parallel, the electric field links across easily. 73, Keith M0KIL.
Thanks for your comments keith. Adding supporting masts in the examples does not make good viewing. There is a reason the stand-off is as far as it is in the video. I guess you did not see the predicted and measured SWR and more importantly curve shapes which track one another very closely?
I don't understand how the feed point is driven. How are the attachment points selected? Traditional J-poles feed across the J but this appears to be two closely spaced attachment points on the main pole. It also appears to be a larger portion of the distance up the stubs. Finally the stub poles seem to be much wider spacing than traditional J-pole. Can you explain these design features? Or have you already done so elsewhere? W5PZT
Thanks for another informative antenna video. Two questions, how does the hairpin handle high winds? I have seen antennas with the hairpin bent in a circle 340 deg around the antenna reducing the area and forces. Would this impact the performance?
Thanks Stan, how the hairpin would stand up would depend on the size and type of material used, 1/4" solid rod has a relatively small surface area but very strong. a circular style hairpin is a good idea as long as the circumference is kept relatively large.
ideally you then use a hairpin at the base rather than the power-sapping, heat radiating coils. This will increase radiating efficiency too. Maybe I will do one?
@ Well if you do please let me know. Atm it’s a local made 5/8 with a coil and 4 radials. Very nicely made but need something that can handle power and very low take off angle. 5-10 deg. Thanks for your reply. Cheers. 👍🥃🇦🇺
Big hair antennas did a co phased 5/8 for cb back around 2000 or so . He sent me prototype I ran it . Very tough tune very tall so wi da were a pain and frankly one of Justin's small ago designs would perform better with alot less winds concerns
why not? it is always going to be 'something' over a 1/2wl as the J-pole has is a halfwave vertical. 5/8wl is the longest single element a single without additional colinear elements so I guess that's why.
Great Video, should call it the Ukraine Trident Antenna
At 11:40 a close up of the Trident feed point, I guess there must be an electrical break in the centre element separating the coax connections.
The bulky looking coax at the feed point is, that for matching or choking, if so how is it achieved? Thanks Greg
I am also unclear on how the coax is attached to the antenna-please elaborate
maybe skip to the section in the video where this section is zoomed into and explained in detail
@@HardcoreFourSix The tube is broken and sleeves over a fibreglass rod. The coax centre is bolted to the tube top section and the braid to the lower.
Making the antenna modeling files available files would be really helpful! In addition, 6 meter and 10 meter versions of the w-pole forker would be amazing! Thank you and 73, K1QS.
I will provide some antenna files although a more comprehensive list of data and antenna files will be available to community members. a 6m Forker is already done. I will cover this and share. I will produce one for 10m too.
Yet another excellent video partly delving into my areas of inquiry.
I was hoping for more information on construction materials, wind and ice loading levels, max voltage along each element and between elements, perturbation caused by material choices, why not put another W-pole above with separate feedline, how to adjust phase without increased impedance (e.g. to increase downward gain from a mountain-peak antenna), how to achieve multiple resonance frequencies (e.g. repeater Rx and Tx frequencies). Of course, some of the above can be explored through use of the published models.
One thing I hope is in my inexpensive/DIY future is a 2m + 1.25m + 70cm single feed car roof antenna I can hook to a tri-band mobile transceiver, TBD. As well as a higher gain separate vertical VHF/UHF antenna that will allow my HT's to reliably reach Puget Sound repeaters through the temperate rainforest vegetation that absorbs SiriusXM before it reaches my my car.
Thanks for the message Larry - the questions you ask would detract from core intent which is to simply antenna design and understanding for the masses. it maybe later down the line we do some drill down in some areas if there are specific requirements or interest.
@@hamradioguys I guess I was expecting to see an adjustable feed position.
I built a 2-armed cactus j pole, with one arm stacked over the other onopposite sides of tbe mast. I used 1/2" copper plumbing pipe.
I feed the top arm as usual, and use the bottom as counterpoise and matching element. I included a 1/2 to 3/4" tee, with the 3/4 out the bottom with another root of pipe. I hard mount it to a mast, so it IS GROUNDED! It works great!
The purpose of the !ower element is to block the RF from a DC connection to allow for this mount to a mast with DC and RF isolation and provide for lightning protection.
I would love to see your take on this variation.
Pix and specs available, should you like to see them.
73, WA4KBT
I learn so much from each video. Thank You.
Thanks for watching! makes it worthwhile..
Really enjoying the channel, and the 50 meg yagi was very timely as I'm just getting into VHF DX. I'm also thinking about a 10m J-pole as well... How do you tell what choking impedance you actually need based on the antenna design?
Ideally you can model and simulate into such tome as there is no difference between no connection to ground or a direct connection with a choke. If you watch the Balun videos, I have a very useful tip for being able to establish common mode currents without the need for expensive equipment or simulation.
I've made few 4m and 6M j-pole works very well for me ,definitely will have ago at this Jpole thanks for this interesting video .
Thank you!
Good informative video.
I made many 2M J-pole antennas (25+) using 1/4-in aluminum rods with these dimensions:
58-in from gnd
18.5-in radiating element
2-in spacing
Fed 2-in above gnd
Mounted in block of aluminum.
Edit add DE KK5R
thanks for the input and comments!
Thanks for the excellent video, I learnt a lot from it. So many rigs are dual-band, I'm sure I won't be the only one to ask if a dual-band 70cm/2m version would be possible in the future.
I have a dual band 2m and 70cms vertical in the plan that is coming soon. I am still testing it but it is far lower profile than the J-pole. keep an eye on the channel
@@hamradioguys Thanks for the reply and your videos. I'll keep an eye out for your new dual-band design
Great job Justin I do enjoy your videos many thanks 73
Hey Thanks Andy, much appreciated.
Great Videos and extremely informative. I would be very interested in a dual band fixed antenna for the SatNogs and Cubesat side of the hobby. If that’s something you could model and make a video on. Thanks.
Thanks for the comments. What are the frequency ranges required for each?
Can I suggest that you put the support pole in the model as well. In EZNEC simulations I've done it's made a profound difference. The induced current in the pole can be as high as 1/3 of the feedpoint current and this seriously effects the radiation pattern.
Even if you use a fibreglass pole, the outer of the coax will pick up in the same way. Making the pole a non-resonant length doesn't work - the induced standing wave is weird. Grounding the pole changes the situation but without significant benefit.
This applies even when the antenna is insulated from the pole. Because the pole and the antenna are parallel, the electric field links across easily.
73, Keith M0KIL.
Thanks for your comments keith. Adding supporting masts in the examples does not make good viewing. There is a reason the stand-off is as far as it is in the video. I guess you did not see the predicted and measured SWR and more importantly curve shapes which track one another very closely?
I don't understand how the feed point is driven. How are the attachment points selected? Traditional J-poles feed across the J but this appears to be two closely spaced attachment points on the main pole. It also appears to be a larger portion of the distance up the stubs. Finally the stub poles seem to be much wider spacing than traditional J-pole. Can you explain these design features? Or have you already done so elsewhere? W5PZT
Thanks for your comments. There is a ferrite sleeve choke (current balun) at the feed point.
Thanks for another informative antenna video. Two questions, how does the hairpin handle high winds? I have seen antennas with the hairpin bent in a circle 340 deg around the antenna reducing the area and forces. Would this impact the performance?
Thanks Stan, how the hairpin would stand up would depend on the size and type of material used, 1/4" solid rod has a relatively small surface area but very strong. a circular style hairpin is a good idea as long as the circumference is kept relatively large.
How would work on 10m 73
would be great at the moment as conditions are so good.
Would love to have a 5/8 over 5/8 for 11 Meters. Something that could handle 10k or so.
ideally you then use a hairpin at the base rather than the power-sapping, heat radiating coils. This will increase radiating efficiency too. Maybe I will do one?
@ Well if you do please let me know. Atm it’s a local made 5/8 with a coil and 4 radials. Very nicely made but need something that can handle power and very low take off angle. 5-10 deg. Thanks for your reply. Cheers. 👍🥃🇦🇺
Big hair antennas did a co phased 5/8 for cb back around 2000 or so . He sent me prototype I ran it . Very tough tune very tall so wi da were a pain and frankly one of Justin's small ago designs would perform better with alot less winds concerns
ruclips.net/video/T3V1hoVJka8/видео.html Why do you have 5/8 over 1/2 Why not 1/2 over 1/2 or 5/8 over 5/8 ?
This (j-pole) antenna is amazing.
why not? it is always going to be 'something' over a 1/2wl as the J-pole has is a halfwave vertical. 5/8wl is the longest single element a single without additional colinear elements so I guess that's why.
I just won’t live long enough to accumulate the amount of knowledge that you possess J!😕