vp2e antenna, drawn for 11m

[xm49north7]

Here is an interesting antenna, I drew it up with measurements for 11m. Hope to get one in the air soon as I can. it emits at a low angle towards the horizon, about 26 ° (effectively 20 – 40 °), it has vertical signal polarisation, and the antenna gain is about 3 dBd! The antenna does not require a Balun and, most importantly, high masts. The radiation pattern is almost circular, the maximum radiation/gain point exists in the direction of the longer wire –

 

[xm49north7]

I will of course get it as high as possible for 11m, this is a ham antenna, believe the original was for 14mhz?? If you google vp2e you will find information.


https://vk2ji.com/equipment/antennas/hb9sl-vp2e-wire-directional-antenna/

 

[xm49north7]

I believe this is what would be called a 5/8th wave L antenna

 

[xm49north7]

 

[Road Squawker]

... edit.... The radiation pattern is almost circular, ...

The original article was written in Russian, and the translation made some errors.

This antenna cannot have circular radiation.

Another translation states "the antenna thus configured has a substantial vertical component with a radiation pattern in a vertical plane."

 

[xm49north7]

The original article was written in Russian, and the translation made some errors.

This antenna cannot have circular radiation.

Another translation states "the antenna thus configured has a substantial vertical component with a radiation pattern in a vertical plane."

Yes what I have read says vertical polarization, I did read thru all the russian stuff I found. My only concern is using this on cb, for line of sight local comms; might not be great, it is meant to be low to the ground this antenna, in the range of 1/4 wave length, not sure what would happen at greater heights. I may try and model this, later in the the week, see what I get. I would think it would need height for local cb use. I am sure it would be fine for dx on the ground as drawn. If it models ok I will likely build one for fun, have built almost everything else, laughs. Yes I have seen this with different measurements, and some drawings way out of scale that , don't match the measurements. My understanding is, it is basically, one wave length long, fed, 1/4 wave length from the end. So will shoot in that area for testing.

 

[xm49north7]

I just fired up the antenna software, there is a 40 meter included, the polarization comes up as horizontal, according to the software (mmana-gal) Plot pretty much as the one I posted. For some reason the articles say polarization is vertical. I will have to presume it is horizontally polarized. Here is what one of articles claims ""But, regardless of how it is described, this antenna distinguishes itself by having an appreciable vertical component, without requiring a ground plane (counterpoise wires). To install the antenna only one mast is needed.""""" the name vp2el, is said to stand for"" vertically polarized 2 element"".

 

[Captain Kilowatt]

Looks like the old off-centre fed dipole which is derived from the Windom. Nothing new. I can't see how it could possibly a 5/8 wave antenna. The over-all length is a full wavelength and even just the long portion is .85 wavelengths long.

 

[kopcicle]

https://www.w8ji.com/windom_off_center_fed.htm
https://sites.google.com/view/kn9b/guanella-current-balun

just for reference^^^^

Anecdotal: mine has a YUUUUGE resonance/dip/sweet-spot/minimal-vswr , from about 27.2 MHz to 28.5MHz. Then again , 134 feet long.


Mine has been installed horizontal, vertical ( yup, tall trees here) , sloper, and inverted Vee. The inverted Vee seems to have a significant observed NVIS component (no surprise) and reports from distant receiving antennas of either polarization were inconclusive (again, no surprise).

As for the translation:

"the antenna thus configured has a substantial vertical component with a radiation pattern in a vertical plane."

I read "substantial vertical component" as cloud burner/NVIS and "circular" as omnidirectional with and or, if , a bit more in the direction of the longer wire.

Keep in mind , the extent of my Russian, Turkic, or Georgian amounts to being able to start a bar fight or knowing when to duck.

YMMV

 

[Road Squawker]

Agree, its a full wl OCF, fed @ about the 1/6 wl point.
The 140 degree angle allows it to develop some gain in the off end direction.

The diagram shows a feedpoint of 50 Ohms, so (if) coax fed, it must be a monoband antenna.

Mounted that low, I don't see how it can not be a cloudwarmer.

 

[xm49north7]

Ok, so does not sound like a very good cb antenna for local, but would work for dx. I was wondering how it would perform up high off the ground, say 50 feet to the top fold. High trees here as well. Yes I like the mostly omni pattern, that was what the article was mentioning as circular. It would appear as square on the plot, so good coverage. Mostly omni. Might try this on the dx. Having great luck with my 2 loop array, but still like to have something on the build to play with. Maybe an array of 2===vp2e for dx.....

 

[kopcicle]

The feed point impedance will go up to approximately 100 ohms at 30 meters/100ft and decrease slightly thereafter. This will not affect resonance to any significant degree. Expect 1.5 - 1.6:1 with significant common mode current on a coaxial feed without balun. Avoiding half wave feed lengths seems to help as well.

Keep in mind that excessive common mode current can torture analyzers and VSWR meters into giving inaccurate readings.

@xm49north7 and @Road Squawker , I know you two know better but I should state again...
A resonant wire dipole (of any variation) need not be, and usually does not have a 1:1 match normalized @ 50 ohms. Trimming the dipole for resonance works. Trimming the dipole for VSWR does not work.

 

[xm49north7]

https://www.w8ji.com/windom_off_center_fed.htm
https://sites.google.com/view/kn9b/guanella-current-balun

just for reference^^^^

Anecdotal: mine has a YUUUUGE resonance/dip/sweet-spot/minimal-vswr , from about 27.2 MHz to 28.5MHz. Then again , 134 feet long.


Mine has been installed horizontal, vertical ( yup, tall trees here) , sloper, and inverted Vee. The inverted Vee seems to have a significant observed NVIS component (no surprise) and reports from distant receiving antennas of either polarization were inconclusive (again, no surprise).

As for the translation:

I read "substantial vertical component" as cloud burner/NVIS and "circular" as omnidirectional with and or, if , a bit more in the direction of the longer wire.

Keep in mind , the extent of my Russian, Turkic, or Georgian amounts to being able to start a bar fight or knowing when to duck.

YMMV

Ah yes, very good observation, I misinterpreted the vertical component as polarization, he means vertically straight up, cloud burner, thank you for pointing that out. 134 feet sounds quite interesting,a tuner would be required I take it.

 

[kopcicle]

a tuner would be required I take it.

There are places in 80, 40, 20. 10m where a transistor radio or amp would easily survive. That distance between 27.2 MHz to 28.5MHz is no higher than 2.2:1 .



Then this bit of overkill. I also feed at approximately 80/20%.
Tuner is a Drake MN2700B

 

[BJ radionut]

https://bonoradio.wordpress.com/tag/vertical-phased-array/

http://www.yf1ar.com/2013/05/2-element-vertical-array-for-160m-and.html