Keep in mind, this antenna offering ideal relationship between length & gain for 3-4 dbd more gain

43 element long yagi for the low end of the 2m band, 98.5' (32.349 m) long portable antenna wuth a high gain 19 dbd

Tips for building Antennas, firstly, build a prototype that is adjustable in as many dimensions as possible

The antenna installed on the roof good results are achieved on 6 and 4 meters, furthermore, the swr on both bands are good, swr = 1 - 1.2

After the very good experience with the 2m / 70cm coaxial antennas, today such an antenna should be weatherproof for outdoor use

It was designed and optimized using 144.250mhz as the center frequency which is in the middle of the SSB portion of the 2 meter band and according to the program has a gain of 11.68dBi with a front to back (F/B) ratio of 37.44dB on a boom length of 8.68 feet

This 2 Meter 300 Ohm Slim Jim antenna is constructed from regular 300 ohm twinlead

The antenna is more or less omni-directional, and horizontally polarized, presents a low-through-high angle of takeoff, and is intended for use in the 144.200

This antenna is nothing more than the coaxial version of the j antenna j pole, see here, it consists of a half-wavelength radiating element, the electrical equivalent of the half-wave dipole, but fed by a tip

A 2.4Ghz low-power 5dBi vertical collinear antenna for 802.11 applications

The antenna uses a impedance matching for the swr calibration, we need a pl chassis in which we connect the flow rate and the coaxial to the radio

L'elemento attivo è un dipolo aperto, l'accoppiamento con la discesa è realizzato con il sistema hair-pin derivato dal delta-match

Il boom è lungo 1,75 m sezione 1,8 x 1,8 cm, il riflettore 50,3 cm, il radiatore 48,9 cm, d1 44,9cm, d2 44,3 cm, d3 40,8 cm, d4 39,5cm

Operating frequency = 130 to 170 MHz, center frequency = 137.5 MHz, perimeter of loops = 227 cm , material used = copper or aluminum = 227x3x0.2 cm, horizontal polarization gain 3 dbd

A square folded dipole radiates in all directions, with -4dB gain on the sides compared to the front and back side

Alimentazione mediante il sistema denominato gamma-match con il condensatore realizzato inserendo il centrale del rg58 completo di isolatore all’interno del tubo di alluminio costituente il gamma-match

6 elementi con l'adattatore di impedenza serve per trasformare l'impedenza bilanciata del radiatore di circa 200 Ohm in una sbilanciata da 50 Ohm

Halos are customarily operated with the plane of the loop oriented horizontally, parallel to the ground, whereas small-loop antennas often are oriented vertically

The Big Wheel is an omnidirectional antenna with horizontal polarization

A discone antenna is a version of a biconical antenna in which one of the cones is replaced by a disc, it is usually mounted vertically, with the disc at the top and the cone beneath

Si tratta di un dipolo a 1/2 richiuso a forma di cerchio,con gli estremi distanziati fra loro,e alimentato tramite Gamma Match

Sostanzialmente una evoluzione della cubicalquad, i due telai quadrati costituiti dal radiatore e il riflettore, vengono piegati a 90 gradi

Sono due loop adiacenti con l'alimentazione al centro, la sua polarizzazione sia orizzontale che verticale

The antenna is more or less omni directional and horizontally polarized,it presents a high takeoff angle and is intended for use in the 144.200mhz area

Gain 15.9 dbci approximately 1 to 1.5 db better than the standard helix antennas i have modeled, pattern: first side lobes at 36 degrees down 14 db average of all remaining sidelobes <25 db, bandwidth: <0.2 db variability from 432 to 438 mhz 50 ohm match at <1.2 vswr from 432 to 438 MHz

This antenna is very adapted at VHF and UHF domain inside 30 MHZ to 900 MHz

The final design balances performance and size,the element for both bands are interlaced and mounted in parallel,all dimensions are in iches director lenght are d1 37.5, d" 36.375, d3 36

In practice are two antennas that are formed by a larger loop and a smaller loop, these loops are shaped to receive a signal on 137MHz frequency

The Flower Pot antenna can be readily modified to dual band

A delta loop also known as a delta loop is called full wave loops wire length = wavelength in the form of a triangle, it can consist of only one or more energized elements emitters. in addition, one or more parasitic elements directors and reflectors can directivity and the associated

Flowerpot is an end-fed half wave antenna for 2m made from nothing more than RG58 coax and 25mm PVC pipe

Omnidirectional vhf grounded to remove static, 7.5dBi gain, bandwidth more then 2 MHz t 1.5 SWR

Rientra nella categoria delle loop è stata inventata e sviluppata attorno agli anni 1970 da un gruppo di tre radioamatori giapponesi JE1DEU-JH1FCZ-JH1YST

When tuning the antenna play on the length of the coaxial 3 mm until obtaining an ideal ROS

Le antenne elicoidali la loro polarizzazione circolare a captare i satelliti polari sia di tipo meteorologico che amatoriale

Simplicity in terms of its performance, equivalence with a Yagi antenna, optimally sized, three elements with wide spaced, or four elements with close spaced

Quad 4 elementi il guadagno da circa 5,87 dbd ad un valore prossimo ai 10 dbd,con un rapporto f/b attorno ai 20 db ed un'impedenza caratteristica di 50 ohm

The quadrifilar helicoidal antenna quite a mouthful is easy to construct even though it does look complicated, and the results are excellent

An omnidirectional collinear, is capable of surviving harsh environments, it's a good choice for repeater installations and can be top, or side mounted to the tower

Detail of gamma match diet,The core of the RG58 is soldered to two 15 pF capacitors in parallel, which are themselves soldered to the gamma match

The dipole is mounted vertically 250mm in front of a metal support, the gain is 2,65dBd at 5,5dB F/B

Antenna helix for 2400 MHz, swr 1,2 2400 - 2440 MHz

The beam is a coax-fed version of the zl-special, the reflector is fed 225 degrees out of phase

The 1/4-wavelength antenna presents its half-dipole current distribution curve, while the 5/8-wavelength antenna provides a half-EDZ distribution curve

I used this antenna aluminum 0f 10mm diameter, or yoy use a brass rod of about 7 mm diameter. the top one is a strong copper bras wire of 5 to 7 mm diameter

On air testing has shown that it is indeed directional,i have a 1.1swr for 144.2 and a 1.8swr for 432.1. 50.125

Questo tipo di antenna funziona veramente bene

Yagi for the 23 cm band drawing by DL9AQ

Mobile, Portable, Base station, Marine, EMCOMM, MARS/CAP, ARES, SATERN, RACES, First Responders, Emergency Preparedness, Skywarn, Military

43 element long yagi for the low end of the 2m band, 98.5' (32.349 m) long portable antenna wuth a high gain 19 dbd