The collinear design is attributed to Steven Merrill KB1DIG. The wire that it would replace was already pretty good so its taken two years to decide to build it.
Thanks to Clint of Oxford Shortwave Log for this coaxial collinear antenna system for 2m and 70cm.
Coaxial collinear antenna design. You can calculate the element length IN INCHES using the formula 5904 divided by the desired resonant frequency of the antenna times the velocity factor of the coaxial cable. Build A 9 dB 70cm Collinear Antenna From Coax By N1HFX Build A 9dB 70cm Collinear Antenna Page 1 of 3. A couple of years ago I designed this antenna which had the good property of substantial low elevation gain and the model generated consistent and predictable 4NEC2 results.
Based on the fat dipole idea the configuration of the classical coaxial collinear antenna is modified and an 8-section coaxial collinear antenna is designed. Full PDF Package Download Full PDF Package. Performance of a 20 Meter Vertical Collinear Antenna.
Enter the required frequency in MHz the velocity factor of the coax. Alternating 180-degree phase shifts at the series connections. Collinear antenna building by Karl Shoemaker.
10 element 13 dBd gain. See older version here 3 element 7 dBd Gain. This paper presents a wideband high-gain coaxial collinear antenna with a stable radiation pattern.
Collinear for VHF and UHF Coax comes alive II the next generation By Mike Collis WA6SVT Original article appeared in the August 1990 issue of 73 Amateur Radio Magazine. A four-element collinear antenna consists of two separate antennas each with two elements and each element 12 wavelength long and mounted vertically so all. This is not an antenna for the beginner antenna builder.
WB3AYW WIRE COLLINEAR FOR 2 METERS. These linear versions of collinear antenna arrays have nearly omnidirectional radiation pattern due to more or less longitudinal axis symmetry. FYI — This was many years ago for a science fair I entered.
Design of a High Gain and Low Sidelobe Coaxial Collinear Antenna Array. Researches in either coaxial 2 or microstrip line antenna technology 34 see Figs. The guiding principle is that we have multiple 14 wave elements fed in series the radiation from each adds in phase to produce a large vertically polarised omni-directional.
Figure 20 Fourth configuration – coaxial collinear antenna connected to the ADS-B receiver via lambda4 protection stub amplifier and 75 Ohm50 Ohm transformer. Note a coax balan is recommended this is needed to keep current from the antenna off the feed line and back to the TX unit. Building a Coaxial Collinear Antenna Discussion Vertical antennas with gain are usually pretty tough to build utilizing tools found around the average home.
Originally I used RG-213 with a velocity factor of 066 or 66 I now use RG-11 or CAC-11 a solid conductor aluminum shield cable for high power antennas and RG-6 for. Collinear arrays usually have a maximum of four elements as a result of problems with trying to keep six or more elements in phase. Collinear principle in antenna design has been summarized based on historical development.
The guiding principle is that we have multiple 14 wave elements fed in series the radiation from each adds in phase to produce a large vertically polarised omni-directional antenna. This is post 2638 in a continuing series of simple ham radio antennas. The paper presents generalized colinear antennas implemented in a multitude of forms and some designs have properties.
This ground-plane collinear design is superior. The bandwidth of the array element reaches to 58 and the gain is 6054dB. Above images show a prototype collinear dipole built for 1090 MHz using this antenna calculator.
For receive only no balan or current choke is needed. Coaxial Collinear Antenna for 70 CM Band – This coaxial collinear antenna was built to test for my own consumption whether or not this antenna method actually works. Improved and theoretical and experimental models for the coaxial collinear antenna IEEE Tans.
A collinear antenna means that it is actually more than one antenna stacked on each other but 1 all working in line with each other and 2 all in phase with each other. Hard to construct matching coils are normally needed as well as hardware and tubing which can be difficult to find. If you fall into this category please read the notes at the end of this article.
Slide three FT50-43 or almost any similar sized toroids over the bottom end of the. A coaxial collinear antenna for 2m and 70cm. Also this design is for two 58-wave antennas hence the name two-element that are in phase with each other.
The -10dB impedance bandwidth of the proposed antenna reaches 365 MHz at a center frequency of 450 MHz. The 2 – 440 Collinear vertical in this project is simple to build and expand semi rigid self supporting water tight electrically sound and a professional appearance when completed. These Collinear antennas are 4 Megs wide and must be supported at the top by a yard arm or tree limb.
5 element 94 dBd Gain. The Coaxial Collinear is rarely mentioned in radio circles odd. A collinear or co-linear antenna is an array of dipoles mounted in such a manner that every element of each antenna is in an extension with respect to its long axis of its counterparts in the other antennas in the array.
A coaxial collinear antenna for 70 CM this coaxial collinear antenna was built to test for my own consumption whether or not this antenna method actually works. Because a collinear antenna is hot with RF along the shield of the coax it is necessary to prevent the RF from coming back through the coax. The classical coaxial collinear CoCo antenna made of sections of coaxial cable is a special case of this new much broader antenna class.
A high-gain and low-sidelobe coaxial collinear COCO array antenna is developed in the UHF band. A Novelistic Approach for Rapid Beam Forming in Smart Antennas for Wireless Applications using Smart-Fractal concepts and New Algorithm. Depending on the materials in your junk box you could build this VHFUHF antenna for almost no cost.
This rugged antenna an omnidirectional collinear is capable of surviving harsh environments. Figure 21 Polarograms of the original antenna and the coaxial collinear antenna – the fourth configuration. Coaxial cable keeps the elements of an antenna in phase.
1 – It seems that the optimal configuration is fourth. Its a good choice for repeater installations and can be. The more common coax collinear requires a PVC radome to give it rigidity and weather proofing and assembly can be difficult.
Calculate the required dimensions for a coaxial collinear antenna construction for any given frequency. However collinear microstrip patch. This article describes a collinear antenna made from very inexpensive RG58U coaxial cable and encased in PVC pipe.
CO LINEAR ANTENNA DESIGN While it is not possible to home-brew a commercial quality antenna it is very feasible to build a collinear antenna for average use.