Peter. My name is Robert and I am an amateur radio operator from Poland. SP5RF It's in Europe. For years I have been watching your movies, which are cheerful, natural and teach us our beautiful hobby. Every time I want to put up a huge mast with an 8-element Yagi antenna at 14 MHz. and I amplify 1000Watt I think about what you propose. 5 watt transmitter, simple equipment, well-thought-out and well-matched antennas and telegraphy. I think what you are doing is quintessential amateur radio. Of course there is nothing wrong with masts and kilowatt transmitters, but connecting to an Australian beach with Slovenia by simple means is an art .... I greet you and wish you perseverance, health and serenity. God bless you. Robert.
When I moved into my townhouse I discovered that a Bobtail curtain had already been thoughtfully provided by the kind architects. Even though everybody else mistakenly refers to it by another name........."a gutter and three downspouts", only I seem to have devined its true purpose so I hooked one of the vertical elements up to a 9-1 unun using the tuner in my Kx3 to achieve a workable match. Varying the length of a counterpoise lets me operate on any HF band even though I am on the second floor. Should I ever decide to go QRO I might even have the added benefit of being able to use the audio from my neighbors television as a convenient monitor, thereby saving wear and tear on my radio's speaker.
Thanks for the insightful video, Peter. I built a 15m inverted bobtail curtain this past week. I attached wire to three 15 foot fishing poles mounted on my six foot PVC fence between two houses. The bottom section of the antenna is 5 feet off the ground. The antenna is current fed, meaning I feed it at the bottom corner where the vertical wire meets the bottom phasing wire, so no There no counterpoise and no radials or ground plane. The "ground" beneath the bobtail is paver stones. Also, no need for a coupler since this is a current-fed antenna. Simply connect the vertical wire to the coax center, and connect the bottom phasing line to the coax shield. Although you can take time to trim this antenna for low SWR, I used standard dimensions then tuned it from my KX3 to about 1:1 SWR. From my QTH on the Atlantic coast of Florida (7 miles inland) and running 5w on an early evening on 15m, my first two contacts were with Hungary and San Francisco. SFI was 87. So, this is really a DX antenna! And inexpensive to build. The next day I worked more 15m DX running QRP from my Florida QTH: France, Italy, and Spain. - 72 Jim - N7RCS
Great video Peter! I’m a big fan of the 1/2 square, and I have one here at home for 40 metres. I’ve got one on 20 that I use for VKFF parks and it’s a winner. Now I’ll have to make a Bobtail to try! I feed mine at the bottom of one of the vertical legs with a 49:1 transformer. That works a treat. Andy, VK5LA
Back in the 97ish there was a magazine that posted "half square antenna" plans. It was a full wave loop, but morphed into a 1/4 wave and another 1/4 wave, bridged by a half wave. You feed it like a loop, with the x .66 1/4 wave of 75 ohm tv coax tapping in where a corner was formed, ground to a 1/4 wave, and center to half wave with 1/4 wave dropping vertical. It will be maybe octave resonant, but really monoband with coax, and you could add halfwaves with 1/4 wave drops to infinity and limit of effort, like a collinear, massively broadside pattern.
Great video Peter, I have tried the bobtail curtain antenna before a few years ago along a quiet stretch of coastline directed to the short path. Unfortunately the location is now not as easily accessible, only on foot which makes it more difficult for setting up. I would like to continue my experiments with this fascinating antenna sometime. I'm surprised they don't seem popular. I have seen some slight differences in designs and didn't know about the 0.6 top length with increased gain. Thanks for sharing and may experement some further with this design in the future. 73 M0DAD
Thanks. Bobtails are seen as a more a low band DX thing. It is assumed that DXers are able to have a beam at least 10 - 15 m high for 14 MHz and up. For them a bobtail might not be of much utility especially as it's bidirectional. But if you can't get that height then I think it has merit.
👍 Very interesting Peter, thanks. A short while back I worked a USA station on CW who said he was using a bobtail. I had to look it up after the QSO. So, perhaps, not a popular antenna on higher frequencies which is surprising as your video certainly indicates that it can provide amazing performance for a simple wire antenna. Some of those EU/NA stations were thumping in and the WSPR plots I think were all DX. Never even occurred to me to try it portable. Given the extra wire is fairly neglige and a couple of extra squid poles is not much extra to carry, will put this one the list of things to try.
Halve those Bobtail dimensions, and it becomes a 10 meter antenna just shy of three meters high and just over 12 meters wide. That would fit in many attics with the elements hung from the rafters. Radiating more at the top would also be a plus in cluttered attics. The only hitch is rotating the house on its foundation. That might prove a bit difficult.
I've modeled a "bobtail" bent 90 degrees like an "L" from a sky view and you get almost omnidirectional radiation with a slight gain north south east west. But overall a lower take off angle. The pattern looks almost like a stacked vertical would at some frequencies and like two intersecting jelly beans at others
ha, you got the whole ham radio prominence of Switzerland in one shot with an FT-817. Wow! (used to be in the same club with hb9afi, when I was living in Switzerland). Keep those videos coming. 73 de jurgen 4z5oi (aka hb9dum), and also owner of an ft-817.
Check out Exclusive beach Gulls way, Frankston. The Bathing box on stilts was made for you, and its great for fishing too. I Learn heaps watching your Vids. cheers
Hey Peter I mocked this up in MMANA. it does very well bidirectional. Then I added the same wire configuration 1/4 wavelength behind it. the gain went up, it almost doubled, and then it was unidirectional. Then I started raising it off the ground and the gain went higher. I ended at 9dBi gain with it a 1/4 wavelength off the ground. this could be a very good antenna with some tree's in the right place to mount it to. I'm sure you could get even more gain working with it more.
@@Siskiyous6 I did a little more modeling after that I made the reflector I made a bit smaller in width while I had it 1/4 wave off the ground, like hagging it from some 70ft trees the gain went to 11. this would be fun to build.
@@curtstacy779 Interesting. However high horizontal antennas also do well. MMANA-GAL says that even a 2 el yagi at 1 wavelength high (ie 66 ft) gets over 11dBi at around 15 degrees.
@@vk3ye Yes but I can't pull a yagi up a tree. lol but the angle I had 11dBi at was 8* I thought that was pretty good for an antenna you could just pull up some tree's. I have many 100' trees this would work good in.
@@curtstacy779 You can if it's a wire yagi. Then it would have the same problem as the bobtail with reflector - ie unidirectional (though you can do things to reverse it).
Commercial shortwave broadcasters used 'Curtain Arrays' to get their signals out, I guess this is sort of based on that concept? I'm impressed with the performance of that antenna, especially you receiving that loud Indiana station on 40 meters in broad daylight! 16:48
Yes. Though a good choice for broadcasters would be Lazy Hs (or stacked horizontal dipoles) with reflectors. Problem with them for amateur portable is 1. you need a good height to get the lower element off the ground and 2. the feedline needs to be brought at 90 degrees away. But if you can sort those out you have an efficient antenna over a 2:1 frequency range.
I think I might try building it with a couple of parachute ropes off the ends, and string it up between 2 trees by a lake. Then put a single pole in the middle for the feeder and hang small weights on both end wires. A couple of big nuts should do.
Hi Peter Awesome and educational videos Just wondering how it compares to that 2 wire Yagi you knocked up a few months ago (especially if you’d made all 3 bands, as per the construction article) ?? Phil VK2JDL
Peter, questions on the construction. I'm assuming that the center conductor of the coax will be attached to the end of the middle 1/4 wave wire and the center conductor is attached to the foil counterpoise? How are the 2 1/2 wave elements and the three 1/4 wave elements connected to each other? Will a LDG Z-817 work to tune this?
clm - you can't use coax with this antenna unless you feed it near the top (which is inconvenient and destroys its multiband capability). You must have your antenna coupler right at the bottom of the middle element. All elements are joined at the top. I can't comment on the LDG but if it matches high impedance end-feds then it should be fine. Personally I prefer manual ATUs.
@1:12 and u need radials 😢and tuner I prefer on top corner with current balun no radials or tuner Bobtail only 1 to 2 db better than half square but again need radials And tuner
Hi Peter worth looking at trying with two trees snd a mast in the middle. Please share details of the “transformer” you’re using, I’m guessing it’s an impedance match of sone description but what ratios? You also mention that it’s not suitable for Coax, how are you feeding it (a picture is worth a thousand words) Great set up btw.
I've seen this video a few times and even made supports to hang a wire in this configuration. But, I am now thinking of trying two (and then three) 5m telescopic verticals (I have about 4) with alligator clipped wires as the horizontal elements and the partially extended verts anchored on converted 3/8-24 mirror mount ground pegs (providing ground isolation). I may have to pull the shoulders out straight with guys to tighten things but am planning to use a tiny 26awg wire. I can easily experiment with various heights/lengths as well as having an easy set up. I imagine the beefier-than-wire vertical elements will improve bandwidth also. What do you think?
Terminate one end of a half-square, and you'll essentially get a EWE. Terminate one end of a bobtail curtain, and you'll get ??? I especially mean low bands, but would be curious what would happen to 10 MHz & up too :)
Anyone that has never heard of the Bobtail Curtain has probably not been a ham for very long. And "Best" is HIGHLY subjective. Best at what? Best All-Band Anttenna (which is what many portable QRP Ops want) ? Certainly not. Why not just call it what it is: an excellent monoband DX antenna?
Setup and take down took 15 min. And it's multi-band. A single vertical with lots of radials to lay would take longer. Three poles is a struggle to carry by hand but if you have a bike they can be strapped to it.
Premiere? Downvote. It is like: „Yay, great. Another video of one of my favourite channels.. a damn it. I have to wait for x hours.“ pure disappointment.
