What can happen with a Horizontal Inverted Vee? (
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- เผยแพร่เมื่อ 15 ก.พ. 2022
- Ed, KN4RWQ, is thinking about taking his horizontal antenna and setting it up on its side to create an inverted vee. Would this work?
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About 10 years ago I made a half-wave 10m horizontal V-beam of 16 ga wire stapled to the ceiling of my radio room on the first floor of my house. The angle was (accidentally) about 120 degrees and fed untuned with RG-58 coax. My rig at that time was a retuned 25w Uniden CB. From my West Coast location I worked dozens of stations in Europe, South America and Oceana. I was flabbergasted at how efficient it was.
Used to be a NAVCOM station in Japan that used a Rhombic antenna for VLF comms to submarines 😊
Those who remember, older TV antennas had the fishbone look. That was the the same principle being applied.
My first HF antenna was a horizontal V. Thanks for the video. N0QFT
You apparently assumed the question was referring to some kind of long wire inverted V antenna. It’s much more likely the antenna in question was a half-wavelength inverted V, which the answer would be quite different. There are posts about bent dipoles online that better answer the question. As I recall, at the base frequency it tends to reduce broadside directivity relative to an unbent dipole, broadening the already fairly broad azimuth pattern and filling the end-on null. When operating on harmonic frequencies the azimuth pattern becomes more complex, but at no angle does it increase directivity relative to a dipole. It’s roughly equivalent to sum if the patterns of two dipole antennas rotated in azimuth relative to each other to form an X, with half the power going to each dipole. That’s not an exact analogy, since it neglects coupling between the two dipoles, but I think it’s close, and much closer than the analogy to a rhombic configuration.
Hi Dave. As usual the question raised by "Jamaica dog" is different and your understanding of the question and hence the answer you tried is different.
Any inverted V dipole whose angle included is 120 degree (to the horizontal) would tend to offer a pattern almost similar to that of a horizontal dipole.
That is the broadside radiation pattern.
When the angle becomes 90 degree it's almost like omnidirectional in the azimuth plane.
He asked what happens to the radiation pattern if the 120 degree V dipole is turned sideways.
He didn't mention if the apex (that's the feed point) is near his house (as you assumed and drew on the board)
But that should be the case because it involves a short coaxial cable feeder from his shack.
He never mentioned that he was going to use multiple half lambda long wire for the dipole. It's quite obvious that he speaks of a simple half lambda centre fed dipole for 40 meter band.
And in this scenario his dipole may have little bit of directivity gain in the direction opposite to where the apex is facing. But then if the building is very near the apex and sufficiently tall and broad some of the signal would be reflected and may get reinforced; or may get destructively interfering with the ongoing signal.
I hope this helps.
De VU2RZA.
Talking about drifting away from the original question.
Interesting side note; the angles of the inverted V roughly correspond to a water molecule (H2O) bond angle (104.5*-109*). Makes me wonder about water conductivity.
inverted v is also used in alchemy , free masonry and in the symbol for l*cifer.
In the military back in the 70/80/90 the Tactical Unit used the inverted V also moved the legs forward on the HF RTTY System.
How about wire beam antennas. I have been wanting to put one up so that I can get Europe or Asia. They were being used before the yagi.
I have that exact antenna up at my place.
Horizontal it is about 110 deg and the inverted "V" is 30 deg below the horizon or 60 deg from the pole.
With that data input into EZNEC it show up as a vertical with lobes off the end of each antenna.
I have made contacts everywhere from west coast the full pacific rim, AUS and NZ and Cape Town So Africa all on FT-8
I have quite a similar Setup with an Inverted V dipole from the house roof to the end of the garden. The angle down is about 20° and the angle of the legs about 15° It seems to behave quite nicely locally, so Europe but unfortunately I have about S8-S9+ noise on all HF bands so I am mostly operating SOTA
As Casler said, keeping that 120 angle is important. It relates to how directional will be, some or a lot. Unless you can model your antenna very closely, any/all the answers are only possible approximations.
Easiest way of finding out would be to just put the thing up and see what happens.
Thanks for answering my question Dave. This antenna is up, with swr of 1.7 on 40 meters. ( I always use the internal antenna tuner to get it 1:1 but im into CW, QRP) The lower wire ended up a little less than horizonal (to coax shield) and upper wire to feed is 45 degrees to 35 ft in the air to the same tree. Recieve is great. I have listened to the Utah SDR online with a less than a second lag but it comes in on my radio first. The dipole is pointed SW. I presume that even though I can hear stations west, Most transmitted signal is going SW and NE, so QSO's are going to be best along the eastern seaboard? Makes me want to put up another one pointing west! Thanks again for providing answers that are hard to find. 73 KN4RWQ
A rhombic is a truly amazing antenna
. As an intercept operator I can vouch for that.. BUT, it is HIGHLY directive.. it works well as a point to point communication antenna.. or at the most an antenna that covers a very few degrees of horizon well.. signals fall of fairly quickly.. I love the antenna, but might not use it as an all purpose antenna, unless i were to use it to keep a regular schedule with one particular distant station..
I know, I know. I pointing out the obvious.
Thank you for the video and explanations. I also read the comment from jamaciadog5603, the one who posted the question.
Maybe it doesn't matter a lot, but I'm wondering 2 things: First is the signal as first shown (with the wires one above the other) vertical or horizontal and 2nd if the antenna is oriented with ech end located the same height above ground (maybe the same height as the feed point) does the signal change orientetion and does the antenna still perform as first shown? Thank you very much.
I made my first dipole yesterday for 11 meter. So approximately 102” on each side. I could not get my Swr down for the life of me when it was horizontal. When I Vd it, my Swr dropped immediately. Is there a proper height for my V?
Dave: A little "off-the-reservation" here, but do you have a camera operator performing your camerawork? I noticed something different in this episode. LOVE your channel!
Can I use a V Beam on 70 cm (for example)? Or even 6 meter?
Much more feasible in terms of wire length if so!
I call mine a LAZY V.... it works quite well..voice all over the world!!
What if: i have a 40 foot dipole. But only 35 feet to work in. Can the ends be turned in a different direction?
Yup. You can also use the squarlo design or shape it in a U like an aircraft rams horn antenna and put some end loading if needed. They all produce a pattern about 3Db below a dipole but omnidirectional rather than bidirectional. Height effect remains the same.