Antena Colinear VHF

6 dB VHF Antenna Colinear.

It is not too difficult to make a VHF antenna with omni-directional properties and has the advantage of 6 dB *. A "Slim-Jim" antenna is quite popular but only about 1.7 dB of gain realized *. I have a problem with my radio station package and decided that the antenna gain is the solution. So now I have a 6 dB gain VHF colinear. I also managed to get another 6 dB or more than my old receiver VHF IC260A tired-out with a little tuning agile. (* - Referred by a simple 1/4-wave whip antenna)

This image shows the basic construction. There is nothing new about the technology, the installation of a half-wave on top of another is very common. Both Marconi and Franklin developed a similar technique, but Marconi is more interested in the capacitive coupling between antenna elements whereas Franklin proposed 1/4-wave stubs in a variety of simple and complex forms (Antenna Engineering Handbook by Jasic). I attended Franklin antenna approach, but using a 4mm hard drawn aluminum rod, supported by cutting bits of nylon cutting board "liberated" from the kitchen (when the wife is not there - of course). Each element and stub are all calculated 1/2-wave length (1030mm) but the pilot had to be about 2 "(5cm) longer stub is folded to form two parallel bars. 5cm apart joined together at one end of the Second. The remaining elements of radiation as a single straight element. the three elements are formed is supported by two pieces and shaped blocks nilon.6 dB VHF collinear VHF Antenna Mount Antenna Mounting 6 dB collinear. I have yet to show the dimensions of the block cut but put in the first picture shows you exactly how they are formed. It all depends on what size wooden mounting boom you have. This of course can be metal, but I got a bit of wood sitting doing nothing on the balcony. The only thing that matters is that the pilot should be 1/4-wave length, excluding end shorted (folded).

Enter the central spacer first then simply push-fit everything together (using a little violence). The holes are vertical / horizontal in the block-end should have the electrical connection between the stub and the driven element. I use a bit of iron (to be attached to the magnet) wire from the lead component, threaded through the holes so that there is good contact between the two. Copper well separated from the aluminum in an atomic scale that, given time, you will find corrosion between the anode and cathode metals such as copper. If you do not know it, most of the resistors and capacitors using an iron wire, just take a magnet and test them. Nylon cut block more than enough to support the elements, even in the wind kencang.6 dB VHF collinear VHF Antenna Mount Antenna Mounting 6 dB collinear. Connections are made 15cm (6 ") from the closed end of this stub stub eat with 50-200 ohm coaxial balun that is not balanced to unbalanced. By using RG58 or URM76 length necessary to form a loop balun 0.33 x wavelength of wave A 1 / 2 to 145 MHz radiation element 1030mm and length of coaxial balun should be about 690mm, folded to form a circle of 345mm. You can, of course, simply roll it up.

I have just seen some articles that were published using this type of antenna is made of copper pipe, but I think that my method is much easier to make and cost almost nothing in both money and effort (if the wife does not catch you). VSWR? I never even customized mine, but do not need it!