A TECHNICAL BRIEFING FOR AMATEUR RADIO OPERATORS “VERTICAL COLLINEAR ANTENNAS: BETTER THAN A DIPOLE?” PRESENTED TO: ARASWF NAPLES, FL 34119 JANUARY 2017 PRESENTED BY: DR. AL TORRES KP4AQI EMAIL: atorres4850@yahoo.com

January 2017: “Vertical Collinear Antennas: Better than a Dipole?” For Year 2017 January 2017: “Vertical Collinear Antennas: Better than a Dipole?” February 2017: “How to See Radio Frequency (RF) Waves: the Carbon Magic” March 2017: “ Classical Modulations: The New Zero Bandwidth Concept ”

PRESENTATION OUTLINE WHAT IS A VERTICAL COLLINEAR ANTENNA? VERTICAL COLLINEAR ANTENNA ATTRIBUTES VERTICAL COLLINEAR ANTENNA CONFIGURATION COMPARISON OF DIPOLE ANTENNAS WITH VERTICAL COLLINEAR ANTENNAS VERTICAL COLLINEAR ANTENNA COMPUTER PROGRAM BUILDING A VERTICAL COLLINEAR ANTENNA SUMMARY

WHAT IS A VERTICAL COLLINEAR ANTENNA (VCA)? The VCA is a rugged antenna, an omnidirectional collinear, it is capable of surviving harsh environments. It's a good choice for repeater installations and can be top, or side mounted to the tower You can obtain approximately 3 - 10 dB of gain over a dipole, depending on the number of elements you use. The higher the gain the narrower the elevation pattern The main elements are constructed from ½ wavelength sections of coaxial cable. You can also do the elements of ¼ wavelength coaxial sections You can “house” the coax sections inside a PVC pipe and allowing the top ¼ wave bare section above the PVC pipe

VERTICAL COLLINEAR ANTENNA ATTRIBUTES Higher gain function than a typical dipole If half wavelength sections are used it will be independent from a ground plane Vertically polarized Good Impedance Matching to 50 ohm coaxial line (low VSWR) Efficient Radiator if made from Copper material Simple to fabricate; can be encased in PVC pipe

VERTICAL COLLINEAR ANTENNA CONFIGURATION

COMPARISON OF DIPOLE ANTENNAS AND VERTICAL COLLINEAR ANTENNAS

VERTICAL COLLINEAR ANTENNA COMPUTER PROGRAM Vertical Collinear Antenna Calculations AT.xls

BUILDING A VERTICAL COLLINEAR ANTENNA FOR VHF Computer Program lets you select the operating center frequency (e.g. 146.07/146.67 MHz) and coax sizes Construction made from popular coax units. Can use RG-213 with a propagation velocity factor of 0.66 Can have multiple elements; elements can be quarter wave type or half wave types If you use half wave type elements, antenna is ground independent

JOINING THE VERTICAL COLLINEAR ANTENNA ELEMENTS

COAX PREPARATION FOR THE VERTICAL COLLINEAR ANTENNA

VERTICAL COLLINEAR ANTENNA 5 ELEMENT PATTERN

THREE ELEMENT VERTICAL COLLINEAR ANTENNA PATTERN

SUMMARY WE HAVE DEFINED VERTICAL COLLINEAR ANTENNAS COLLINEAR VERTICAL ANTENNAS ARE MORE EFFICIENT THAN DIPOLE ANTENNAS (HIGHER GAIN) COLLINEAR VERTICAL ANTENNAS ARE EASY TO FABRICATE; DESIGN CALCULATIONS ARE PROVIDED BY THE KP4AQI EXCEL COMPUTER PROGRAM CAN BE FABRICATED FROM ANY SIZE COAX PROVIDED THE PROPAGATION VELOCITY OF THE COAX IS KNOWN. SIZE OF THE COAX DICTATES THE POWER HANDLING OF THE ANTENNA

MORE INFORMATION or COPY OF PRESENTATION SEND AN EMAIL TO THE FOLLOWING URL: atorres4850@yahoo.com CONTACT ME AT: AL TORRES KP4AQI P. O. BOX 24283 DAYTON, OH 45424-0283