Wyowanderer777 yup, some of the best memories of my life are my dad showing me how to use his TRS-80 computer back in the 80s, me and dad going caving and him showing me how to photograph large caverns by leaving the shutter open and walking around firing a flash unit, and any number of other great hobbies we did together! Keep it up, he will love you for it!
It's totally super that you'll have videos of you and your lad doing cool projects together!! He'll treasure these more than you could ever imagine!! Nice going, brother!! Your radio bro, Norman.
I've spent the last 30 years as a HVAC technician. Watching you solder was rather painful. A word of advice. Heat the fitting not the pipe. I wish we could have watched you bend that copper. Now that's nice looking work
I'm glad I wasn't just thinking this. I am glad to see these types of antenna projects being tried by us to at least see more that iComs and beams. Other types are buildable and just as useful for most parts.
A tip. You can use a pair of 3/4" straps folded around the 1/2" pipe and held by a brass nut and screw to form an adjustable feedpoint. Tack solder the coax to one side of each strap tab end for the connection. Goop the coax braid to prevent rain water wicking. VA7WN
Vintage Josh. Been driving all day, 22-Sep-2022, listening to RU-vid videos categorized under "ham radio." In one (I'm guessing circa 2019-- I was driving so couldn't look) Josh mentions his copper super J-pole video, so I came looking for it after work. Currently just preparing to make a roll-up, but working with copper seems fun, too. Anyway, Josh also mentioned two things in that other video I cannot grasp. First was some story he assumed we had heard before about Freddie Mercury and an Abbree antenna. Nope. Never heard it, and cannot imagine. Next, he mentions an amateur radio-related film called "Night," or "Knight." My search for such a film returns nothing. Now, off to find the first part of this video.
Great video man I'll be making one of these. May I give you a tip as a plumber regarding soldering. If you heat the pipe mainly not the fitting you'll have a better joint and also wait until you get a greenish hue when heating the pipe and then apply solder and then it will flow right in there. Cheers buddy. Tim (UK)
Built a 70cm version of this antenna. Made a discovery about the mast if conductive. It is all fine but if by accident you make it some resonant length that coincides with the design frequency it can pull the tuning. The mast itself will radiate. You can check this with a Nano VNA on a wide sweep. Slide your hand along the mast and observe phantom SWR notches move about on the display. Tuning with the antenna on the ground is different than aloft on a conductive mast. My solution was to repeat the insulator section again (without the hairpin) just under the "T" fitting. Then too, a ferrite choke installed close to the feed point is a good idea. This could explain why some people have good results while not others. Just depends on their arbitrary mast length. VA7WN
Many good comments on proper way to solder plumbing pipe and joints so I won't add to that. Thanks for the design link update. more is explained than you provided. Glad it works for you. You are correct. It would have been nice to see the tuning procedure. Don't take my criticisms to heart. I am sure that you have improved since making this video. 73 OM
I put little things on the top of my copper tubing that can slide over the tubing. They are sold to cut down on the water pipes making noise. They are bigger around than the tubing so it can slide up and down for tuning!
I have my 2 meter J-pole up for four years with no problems exapt for poor matins ( op errors) just seal up the two coax leads and inspect it quarterly or yearly. but I am a "new" young ham 4 years in my first term.
When you put a bare copper antenna outside does the tuning/efficient change when it gets tarnished and turns green after a couple of years? What happens with RF travelling on the outer surfaces of the antenna (skin effect) now you have added resistances in the surface there were not there when it was fresh & new.
I’ve had j pole up copper for several yrs it got nice green patena on it still works great haven’t done nothing to it, but you can paint them won’t effect anything
I found plans for the "Cactus" antenna but, according to the plans, that specific design was meant for dual band (144/440mhz). Are your measurements specific for the 2m/144 only???. From what I understand, the upper portion/coil and top will only allow the 440mhz to radiate due to the high impedance. Thanks for sharing!.
I would have cut the 1/4" tubing and soldered it back together with a small coupling rather than try and solder next to a PVC nipple.That has a high probability of melting, even if you use heat dissipating gel. If you could have fitted a 1/2 x 1/2 x 1/4" T in there and gotten the right SWR it would have been great.
It’s just a means of creating a delay so the top half of the antenna is in phase with the bottom half. If the coil wasn’t there the top half of the antenna would be 180° out of phase with the bottom half and there would be virtually no radiation from that antenna.
Hosh... You're in Cali so I have to assume that is not lead solder. 95/5? Does it matter what the composition of the solder is? I am a plumber who just got his tech license so I want to build this... BTW... Try wrapping a wet rag around the plastic nipple before you solder the copper. Or better yet, use a pvc union.
can't one make a j-pole with 2 meters on one side and 70 cm on the other??? and wouldn't it TX and RX better? I'm new to antenna making but am trying to make some so I can get on some distant repeaters.
Anyone have plans for this with ALL the measurements, including the "halo"? Video kind of skipped that part. Nice looking antenna. May qualify as yard art.
Hey man good video! Is there a formula or something to to how long is too long for feedlines? Like where I want to mount my antenna is like 100 feet from where my radio is.
If you are 100 ft away your loss is going to be "bad" on 2 m and horrible on 440 unless you invest is $$$ feedline. It'll still work with decent rg8 but you will have appreciable loss
whats the purpose of adding the halo? how does it compare to a standard J-pole? how does it compare to a "slim-jim" -- would it be possible/practical/beneficial to add the halo to a "slim-jim", and/or would it be beneficial to add more halo's?
To make the antenna larger (1.5 wave + matching stub), you could add, on top, another phasing section (halo) and another half wave section above it (same dimensions at the current top section). You can go on adding sections like this, though mechanical strength is an issue at these wavelengths (though easier at higher frequencies!). You get diminishing returns as you add more sections.
An easier way to do the plastic insulator would be to use shark connectors you can buy the solder on ones or the double ended slide on version then just slide a piece of plastic pipe in after no heat to melt anything
+Bartlett Mayo I have not experimented with anything other than what I showed in the video. I'd stick to the plans unless you wanted to try different things,
+hoshnasi Was that particular design for a specific purpose? Or was it just easier to create? Is there a diameter that you used to create the 'fold back or the diameter around the main antenna?
hi, i don't understand the J Antenna Model you short the signal power to the Ground !please explain , if i have 65 watt power output and i short it to the ground by the J antenna. thanx. all my antenna its depole. signal positif top and the ground down
Mark, I think I understand your confusion... It looks like a short because you have the center coax conductor and the coax shield connecting to a continuous copper conductor. Just remember that what looks like a short circuit to DC is not a short circuit to RF, there is enough electrical distance between the 2 connection points to allow the alternating RF energy to do its magic. I hope that helps. I think Ham universe has a good explanation on how SlimJims and J poles work. 73
Great bending of the loop, but the attachment techniques need some work. Heat the part with the greatest mass, and don't be afraid to use flux. I am a mechanical engineer/building contractor with specialties in electrical and plumbing (and a U.S. "Amateur Extra" licensee!), and the soldering (not "brazing") could use some guidance. What you did was serviceable, but why not make it "permanent and beautiful" as well?
Broadcasting?? Kerchunking?? What kind of amateur are you? :P Thanks for the video. I might end up trying to build one of these in the near future. I'd like to get a full-time VHF base going for monitoring/talking with the local amateurs.
The halo is to create a co-linear design on 2m. The fact is that 70cm = 3 times the frequency of 2m so many antennas on 2m will also work to some degree on 70cm. The radiation pattern may be a bit weird though.
Don't forget to polish it every week. It wouldn't be a bad idea to paint it or something to keep corrosion at bay, and seal the end of the coax or enclose it in a box. Bill, G4GHB.
@@ahuggins6 I have a 6m dipole which I was given and was corroded underneath the SO239 socket on it and so making a poor connection to the centre of the dipole. Painting it after it is assembled would help to keep out moisture, and rain if it's outdoors to help prevent corrosion forming. Corrosion because of moisture creeps up old coax cable from the cut end if you have ever seen old coax. Bill, G4GHB.
@@ahuggins6 The connector is the important bit, but you could paint the whole antenna if you wish. I remember an old radio book which said to clean the unvarnished copper long wire antenna with wire wool to keep it clean. Most amateurs use pvc covered wire these days so I guess nobody thinks of that now. I have sealed coax with bathroom sealant but I believe that contains acetic acid which could start corrosion so that's not the best idea. I've had antennas up using it for a few years though. I understand there is something called Coax-Seal but I've never seen it. On my 40m dipole I enclosed the centre connection in a plastic box to keep rain off with small holes in the bottom to allow air to circulate. I arranged the coax to point downwards to further stop moisture being pulled downwards by gravity, didn't seal the coax. It's debatable whether to seal things or not to seal things and people have different ideas on this. There's still air present in everything and condensation will form in cold weather.
put heat on the side you want the solder to run towards. Most of the time you had the heat on the wrong side. Doing it this way will pull the solder into the joint and then you will have a solid joint. Good video otherwise .
Harley Rev The hottest point is at the tip of the cone, so hold the flame so that the tip just touches the fitting. It's not necessary to heat the copper tube directly, because the fitting quickly conducts the heat to the tube inside the joint. When the temperature of the copper reaches the solder melting point, the solder wire you're holding against the copper will suddenly liquefy and flow into the joint. Hold the solderopposite the flame, the coolest point, to make sure all parts of the joint are hot enough. Solder won't fill spots that are cooler than its melting point. www.google.com/searchhowtosolder
What Harley is saying, is to hold the flame, or in his words "heat" on the fitting, i.e the coupling, elbow, cap etc.. NOT the tube, yes Bobby you are correct in that sense, but Harley was misunderstood in the sense of reference to what point, be it the opposite or same or perpendicular etc.. side to the solder.
.as soon as my money is straight, I'm building a super j-pole for 10-11 meters. With the lower portion below the matching hoop made with 1" copper and top with 1/2"
hoshnasi well Dave tadlock shows a standard j-pole being made for cb and it was 27 feet there abouts. So add 1/2 wave more. But his used twin lead for the lower part.
Sorry, but that ain't braising ! That's (sloppy) soldering (if it doesn't suck up the Tin, pushing it into the joints won't help it either..... Braise is a silver or brass alloy (hence the term "braise") as an welding material and needs red hot temperatures. Soldering is melting a tin-lead based alloy (some contain 2% silver if you go fancy ;-) but still it's melting at max 280 degrees C. if you go wild. Braising takes a good 600-800 C and up. And you'd use oxygen with the propane gas to achieve the needed temperatures.
joostle is correct. Soldering is fine for this purpose, but is very different from braising and welding. Making a technical video? Be accurate with your terminology.
Man I hate to be so hard on you but if you had took a 15-minute lesson in welding pipe I think it would have been a better video then I have never seen anyone solder braze weld or whatever is bad as what you have shown me I don't know where you got your Technique man but I hope you're better now LOL! Not trying to be a bummer dude just trying to give you a little constructive criticism LOL!
