Just Kif DIY Antenna NVIS AKA Cloud Burner Antenna Jutilizzaw Mag Mount

首图.png

  

Parti milli tkun sewwieq tar-radju tal-perżut huwa li tagħti komunikazzjonijiet fi żminijiet ta 'sitwazzjonijiet ta' emerġenza. Bl-Ohio NVIS Antenna Day li ġejja, għażilt li nħares lejn l-antenni NVIS. L-antenni NVIS, imsejjħa addizzjonalment bħala antenni Skywave Vertikali ta' Avveniment Qrib għandhom angolu għoli ta' radjazzjoni. Xi ħaġa fl-ordni ta '60 grad, biex direttament għal 90 grad. B'differenza sinjali UHF u VHF, li normalment ikollhom medda ta '50 mil b'antenna yagi 'l fuq, u wkoll antenna NVIS hija magħmula għall-interazzjoni fil-varjetà ta' 75-- 500 mil. Kultant antenna NVIS tissejjaħ "cloud heater" peress li tgħaddi ħafna mir-radjazzjoni tagħha 'l fuq minn antenna regolari.

  

The idea with an NVIS antenna is to emit as much power as possible at a high angle and also have it be reflected off the ionosphere. From a functional viewpoint, NVIS communications happen at 10 MHz as well as below. One more part of the NVIS antenna is the reality that it is quite low to the ground. This aids emit the signal at a high angle, as well as making it easy to release. There are numerous opinions regarding the most effective height of an NVIS antenna, however, everyone seems to settle on approx. 1/8 wavelength above ground and often much less.

  

I wanted an NVIS antenna that was portable, easy to set up, as well as low-cost (of course). As it ends up, I had practically everything handy. For my NVIS antenna, I began with my 2-meter mag place for my car. After that, it was simply a matter of affixing a quarter-wave cord to the mag mount, then simply stringing the cord flat from the mag place to a tree or a pole of some type.

  

I wished to be able to connect to the mag place promptly. I generated a spring-loaded battery clip. But not just any battery clip. It had actually had the ability to stand up to a strong straight-pull without coming off of the mag mount antenna. What I thought of is shown in the photo listed below:

  

1.jpg

   

Sometimes these are called Crocodile battery Clips, or Test Clips. I selected my own up at the local NAPA car parts store. There are a couple of different sizes. You will require to make certain that the jaws widen adequately to secure onto the base of the mag install you will be utilizing.

  

So currently it's simply a simple matter of connecting a cable onto this clamp. I picked to take the screw out of the backside of the clamp as well as slip the cable with the hole and solder the cable onto the clamp. These aids provide more toughness as this joint will certainly be under some stress.

  

Below is a photo of my mobile NVIS antenna on top of my Jeep making use of the mag place:

   

2.jpg

   

Concerning the length of the wire to utilize, in my instance, I am making use of 40 meters for the Ohio NVIS Antenna Day. One would certainly believe that the classic formula for a quarter wavelength vertical would certainly work. However, that seems to not hold true. Given that this NVIS antenna is so short as well as close to the automobile, my first attempt using the formula 234/ freq. to get the size of wire offered me a vibration of 8.6 MHz. By the way, having an MFJ antenna analyzer aids significantly with this procedure. So equipped with this information, I did some back figuring and thought of my own constant for calculating the correct length of this type of NVIS antenna. That is not to say this is cast in stone, yet this is what helped me, at the very least this time around.

   

<h2>The new formula I have actually developed is as follows:

   

Length (ft.) = 261/ F (mhz).

   

Below is an additional image of my NVIS antenna totally deployed. Notice that at the far end I am making use of 2 4 ft. military fiberglass tent poles that I grabbed in your area.

   

3.jpg

   

My preliminary results show that it appears to function well for an NVIS antenna. I will likewise be including a 75-meter leg to the setup in the future also. That is a simple matter of distributing the cord, including the clamp to connect to the mag install, as well as releasing.

    

This short article was originally uploaded on www.mikestechblog.com Any kind of recreation on any other site is banned as well as an offense of copyright regulations.

tags

Aqsam dan l-artikolu

Ikseb l-aqwa kontenut ta’ kummerċjalizzazzjoni tal-ġimgħa

Werrej

    Artikli relatati

    INKJESTA

    IKKUNTATJANA

    contact-email
    kuntatt-logo

    GRUPP INTERNAZZJONALI FMUSER LIMITED.

    Aħna dejjem nipprovdu lill-klijenti tagħna prodotti affidabbli u servizzi meqjusa.

    Jekk tixtieq iżżomm kuntatt magħna direttament, jekk jogħġbok mur fuq Ikkuntatjana

    • Home

      home

    • Tel

      Tel

    • Email

      email

    • Contact

      kuntatt