Transmission Lines VE3KL An Overview of Transmission Line History Some Theory Cable Measurements Oliver Heaviside Invented Coax Cable Patent No. 1407, dated 6th April 1880 Published Telegraphers’ Equation 1885 E Layer (co-predictor) 1902 Kennelly–Heaviside layer 4/26/2017 David Conn VE3KL

History leading to the Telegraphers Eqn. Presentation Outline History leading to the Telegraphers Eqn. Basic theory…… defines how we measure and maintain cables Measurements of Zo and VF….hands-on Trouble Shooting Cable Problems A mission statement from Lee De Forest 4/26/2017 David Conn VE3KL

History 1850: First submarine cable across the English Channel: England to France. It was simply a copper wire coated with gutta-percha, without any other protection. 1855: Lord Kelvin; diffusion model of the current in a submarine cable….R/C only…like heat transfer….leading to the answer Red Experiment Blue Theory A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

History The investor,chief engineer and foreman ? 4/26/2017 A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits http://connect.in.com/submarine-cable/photos-1-1-1-bcdd6bb7af7ca47da0b5d51910247b3c.html#image_button 4/26/2017 David Conn VE3KL

History 1858: Trans Atlantic Submarine Telegraph Cable…. Western Ireland to Heart's Content in eastern Newfoundland.. Not successful..plagued with problems 0.1 WPM Morse Code A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

History 0.1 WPM 1858 New York Celebration After the first messages were transmitted over the Atlantic Cable in August 1858 between Valentia, Ireland, and Trinity Bay, Newfoundland, September 1st was declared as the official day of celebration in New York City. 0.1 WPM A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

History 1873: Maxwell publishes "Treatise on Electricity and Magnetism“: Four Mathematical Equations form the basis of all modern transmission lines and wave propagation. 1880: Heaviside Invents the Coaxial Cable 1885: Heaviside published the first papers that described his analysis of propagation in cables and the modern form of the Telegrapher’s Equation. A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

History…theory Before/After experiments 1893: Heaviside Publishes book on Vector Calculus…(vectorial, vectorist’s)….easy to use in E/M applications 1950: First submarine cables using coax and repeaters. A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

History 1956-1978: Transatlantic No. 1 (TAT-1) was the first transatlantic telephone system. Scotland to Newfoundland. Thirty six telephone channels. Coaxial Cable, Vacuum tubes and Repeaters A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits http://www.iscpc.org/information/Gallery%20Images/Aft_Sheaves_GMSL.JPG 4/26/2017 David Conn VE3KL

History 1960’s: Photograph of a Repeater Repeater Equalizers Custom Designed on the Ship Measure ship to shore frequency response Use a slide rule to design an equalizer Build the equalizer on site Put into repeater box. Drop over the side! A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits http://connect.in.com/submarine-cable/photos-1-1-1-6c352e7a522a115a21e4f91a4af6fb56.html 4/26/2017 David Conn VE3KL

History Modern Cables use Fibre Optics 4/26/2017 David Conn VE3KL A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits http://en.wikipedia.org/wiki/Submarine_communications_cable 4/26/2017 David Conn VE3KL

Oliver Heaviside: Telegrapher’s Equations History Oliver Heaviside: Telegrapher’s Equations Leads directly to: Waves, Velocity of Light Characteristic Impedance, Zo Vf, SWR, ρ, Losses, Phase Transmission Line Loading Smith Chart A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

Coaxial Cable Basics Characteristic Impedance : a complex number Outer Diameter Resistance R [Ohms per metre] Inductance L [Henrys per metre] Conductance G [Mhos per metre] Capacitance C [Farads per metre] Inner Diameter Characteristic Impedance : a complex number A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

Coaxial Cable Frequency Response Outer Diameter Resistance R [Ohms per metre] Inductance L [Henrys per metre] Conductance G [Mhos per metre] Capacitance C [Farads per metre] Inner Diameter A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

Coaxial Cable Basics Attenuation Constant α Outer Diameter Inner Diameter Resistance R [Ohms per metre] Inductance L [Henrys per metre] Conductance G [Mhos per metre] Capacitance C [Farads per metre] Attenuation Constant α 4/26/2017 David Conn VE3KL

Coaxial Cable Basics Velocity Factor Vf…velocity wrt. speed of light Outer Diameter Inner Diameter Resistance R [Ohms per metre] Inductance L [Henrys per metre] Conductance G [Mhos per metre] Capacitance C [Farads per metre] c = velocity of light in a vacuum Velocity Factor Vf…velocity wrt. speed of light Used to cut phasing lines accurately: first time. A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

Time for a Break Let’s do some Measurements: Zo,VF LC Meter 700 KHz MFJ L/C/R/ρ Ham Bands Vector Z Meter 0.1 to 170 MHz A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

Measurements: Zo, VF Use an LC meter to measure L and C of a 2 metre section of RG8-X Measure L of the shorted cable Measure C of the open cable Use Excel, hand calculator or slide rule to calculate Zo, VF A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

Measurement Results Length = 2 metres Measure Co of the open cable Measure Ls of the shorted cable A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Ls = L = Ls/length = Co = C = Co/Length = Zo = Vf = 4/26/2017 David Conn VE3KL

Measurements Requiring Vector Meters Complex Characteristic Impedance Zo = R + jX……. A complex number Measure the impedance of a shorted cable, Zsc Measure the impedance of an open cable, Zoc Cable should be approximately 1/8 wavelengths long A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits See reference 1 for details 4/26/2017 David Conn VE3KL

Example VE3KL Zo Measurements RG8-X… 2 Metres Long @ 41 MHz Zoc = 1.76 + j 39 Ohms Zsc = 1.16 – j70 Ohms Zo = 52.3 –j0.75 Ohms A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits Aim 4170 Used 4/26/2017 David Conn VE3KL

Measurements Requiring Precision SWR/ρ Meters Insertion Loss Measurement Measure the ρ1 of a Loaded cable: ZL1 = 25 Ohms Measure the ρ2 of a Loaded cable: ZL2=100 Ohms Cable should be long……10 metres at 30 MHz A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits See reference 2 for details 4/26/2017 David Conn VE3KL

Example Al1H Loss Measurements RG-58A 7.62 metres long Frequency = 10 MHz ρ1 = 0.316 ρ2 = 0.299 Loss = 0.35 dB A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits MFJ 259B Meter Used 4/26/2017 David Conn VE3KL

Trouble Shooting Cable Problems Perform a visual inspection for nicks and bulges. 2. Measure the DC resistance of a shorted cable. High resistance indicates a corrosion problem RG8-X has a total DC resistance of 25 Ohms per 1000 metres A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

Trouble Shooting Cable Problems 3. Place a 25 Ohm load on the cable and measure SWR If the cable loss = 0 dB, then SWR = 2.0 If cable loss = 1.0 dB, then SWR = 1.72 A 50 Ohm load does very little for loss measurements Place a 50 Ohm load on the cable Measure the SWR over a broad frequency range to determine if the connectors are working properly. A large band pass ripple indicates poorly assembled connectors A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

TL Details AC6LA 4/26/2017 David Conn VE3KL A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL

VY 73 Dave VE3KL Lee De Forest “If you haven't a hobby--get one. Ride it. Your interest and zest in life will triple. You will find a common ground with others--a joy in getting together, in exchange of ideas --which only hobbyists can know. Wireless is of all hobbies the most interesting. It offers the widest limits, the keenest fascination, either for intense competition with others, near and far, or for quiet study and pure enjoyment in the still night hours as you welcome friendly visitors from the whole wide world.” Lee De Forest 4/26/2017 David Conn VE3KL

References TCA Jan/Feb 2011 VE3KL column TCA Mar/Apr 2011 VE3KL column Measuring Cable Loss AL1H QEX May/June 2005 Transmission Line Zo vs. Frequency N6GCE (http://prc68.com/I/Zo.shtml) TL details http://www.ac6la.com/tldetails.html Coaxial Cable History: http://en.wikipedia.org/wiki/Coaxial_cable Coaxial Cable Time http://www.google.ca/search?q=history+of+coaxial+cable&hl=en&client=firefox-a&sa=G&rls=org.mozilla:en-US:official&channel=s&prmd=ivns&tbs=tl:1&tbo=u&ei=vXYrTYOYHcHtnQeU1LHkAQ&oi=timeline_result&ct=title&resnum=11&ved=0CG0Q5wIwCg A method that you can use easily to evaluate your own noise environment A method that you can use to evaluate the quality of the ionosphere at any give time. Some methods to control received noise The Shannon Hartley limits 4/26/2017 David Conn VE3KL