coax: the critical linkmil-hdbk-216 published in 1962 standardized rg and ug terminology in the...
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Coax: The Critical LinkAs Presented: 2018 ARRL New England Convention
Boxborough, MA
By: Jeremy, KB1REQ
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
Background on Coaxial Cable
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Why we use Transmission Line“When the length of the conductor is comparable to the wavelength of the signal, the conductor must be considered as a transmission line”
Transmission Lines allow us to have the same signal at various points in the RF network
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Transmission Line Forms
http://slideplayer.com/slide/10648036/
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Coaxial Transmission Line
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Why we use Coaxial Transmission Lines
https://www.st-andrews.ac.uk/~jcgl/Scots_Guide/audio/part6/page3.html
VS.
https://blog.lamsimenterprises.com/2011/02/22/coaxial-transmission-line-geometry/
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
The model of a Transmission Line
https://www.intechopen.com/books/current-trends-and-challenges-in-rfid/radio-frequency-background
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Impedance of Coaxial Transmission Line
● Given two coaxial lines made from the same materials and with the same diameter outer conductor
● The cable with the smaller diameter center conductor will have a higher impedance
● The cable with the larger diameter center conductor will have a lower impedance
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Why 50 Ohms?Ideal Impedances:
● Power Handling: 30Ω● Voltage Handling: 60Ω● Low Energy Attenuation: 75Ω
Compromise Impedance:
● 50Ω
https://www.belden.com/blog/broadcast/50-ohms-the-forgotten-impedanceCoax: The Critical Link ©2018 Jeremy Breef-Pilz
RG “Radio Guide”
● MIL-HDBK-216 published in 1962
● Standardized RG and UG terminology in the industry
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
MIL-DTL-17● Released in 1970s,
currently Rev. J, 2014● More stringent standards
for Coax cables● Includes both legacy RG
cable and new designs
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Properties of Coaxial Cables
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Coax MaterialsCenter Conductor
● Copper, Aluminum, Steel, Silver
Dielectric
● Air, Polyethylene (PE), Polytetrafluoroethlyne (PTFE), Tetrafluoroethylene (TE)
Outer Conductor
● Copper, Aluminum, Silver
Jacket
● Polyvinyl Chloride (PVC), Cross-linked Polyolefin (XLPO), Polyethylene (PE), Thermoplasic Elastomer (TPE), Fluorinated Ethylene Propylene (FEP)
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Construction TechniquesCenter Conductor
● Solid, Stranded, Plated
Dielectric
● Solid, Foamed, Taped
Outer Conductor
● Braided, Foil, plated
Jacket
● Flooded, Armored
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Electrical Parameters● Nominal Impedance ( )● Maximum Frequency (GHz)● RF Loss (dB/distance @ ƒ)● Maximum RF Power (Watts @ ƒ)● Capacitance/Inductance (pico-F/distance) (micro-H/distance) ● Velocity Factor/Propagation Delay (%)● Maximum Voltage (V)
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Mechanical Parameters● Dimensions● Minimum Bend Radius (distance) (single, repeated)● Weight (weight/distance)● Temperature range
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Traditional Coax Cables
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-58Can have a solid…
Standard: RG-58U
Center Conductor: 20AWG solid
Nominal Diameter: 0.193”
Minimum bend radius: 2”
RF Loss: 8.4dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 19.1 Watts out
Price: $0.30/ft.
(Belden 9201)
Or stranded center conductor
Standard: M17/28-RG058 (RG-58C/U)
Center Conductor: 20AWG stranded (19x33AWG)
Nominal Diameter: 0.195”
Minimum bend radius: 2”
RF Loss: 11.5dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 13.3 Watts out
Price: $0.32/ft.
(Belden 9203)
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-8Standard: RG-8/U
Center Conductor: 13AWG stranded (7/21AWG)
Nominal Diameter: 0.405”
Minimum bend radius: 4.05”
RF Loss: 6dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 25 Watts out
Price: $0.91/ft.
(Alpha 9008)
Standard: RG-8/U
Center Conductor: 11AWG stranded (7/19AWG)
Nominal Diameter: 0.403”
Minimum bend radius: 4”
RF Loss: 3.9dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 31.9 Watts out
Price: $1.35/ft.
(Belden 8214)
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-213Standard: RG-213/U (M17/74, M17/163-00001)
Center Conductor: 13AWG stranded (7/21AWG)
Nominal Diameter: 0.405”
Minimum bend radius: 5”
RF Loss: 4.1dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 31.2 Watts out
Price: $1.00/ft.
(Belden 8267)
Difference between RG-8 and RG-213?
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-8XStandard: N/A
Center Conductor: 16AWG stranded (19/29AWG)
Nominal Diameter: 0.242”
Minimum bend radius: 2.5”
RF Loss: 6.6dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 23.4 Watts out
Price: $0.55/ft.
(Belden 8267)
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-174Standard: RG-174/U
Center Conductor: 26AWG stranded (7/34AWG)
Nominal Diameter: 0.110”
Minimum bend radius: 1”
RF Loss: 19dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 5.6 Watts out
Price: $0.17/ft.
(Belden 8216)
A dual-band “Mini-Magmount” antenna with 9 ft of RG-174 cable,
Will see 2.7 Watts from a 4 Watt HT on 70cm
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Lower Loss Designs
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
The first attempt… Belden 9913
Major Risk: Water intrusion
Standard: N/A
Center Conductor: 10 AWG solid
Nominal Diameter: 0.405”
Minimum bend radius: 4”
RF Loss: 2.6 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 37.1 Watts out
Price: $0.90/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
LMR-400Environmental variants:
● DB - Direct Burial (watertight)● FR - Fire Retardant (riser)● PVC - PVC Jacket
Standard: N/A
Center Conductor: 10AWG Solid
Nominal Diameter: 0.405”
Minimum bend radius: 4”
RF Loss: 2.6dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 37.1 Watts out
Price: $0.94/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
LMR-400-UFULTRAFLEX
Standard: N/A
Center Conductor: 10AWG Stranded
Nominal Diameter: 0.405”
Minimum bend radius: 4”
RF Loss: 3.2 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 34.6 Watts out
Price: $1.34/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Popular sizes:
● LMR-600● LMR-400 (RG-8 Size)● LMR-300● LMR-240 (RG-8X Size)● LMR-200● LMR-195 (RG-58 Size)● LMR-100 (RG-174 Size)
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
LMR-240Standard: N/A
Center Conductor: 16AWG Solid
Nominal Diameter: 0.240”
Minimum bend radius: 2.5”
RF Loss: 5.1 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 27.8 Watts out
Price: $0.64/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
LMR-240-UFStandard: N/A
Center Conductor: 16AWG Stranded
Nominal Diameter: 0.240”
Minimum bend radius: 2.5”
RF Loss: 6.1 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 24.8 Watts out
Price: $0.83/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Lower Loss Where?
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
LMR-195Standard: N/A
Center Conductor: 19AWG Solid
Nominal Diameter: 0.195”
Minimum bend radius: 2”
RF Loss: 7.4 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 21.3 Watts out
Price: $0.51/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
LMR-100AStandard: N/A
Center Conductor: 25AWG Solid
Nominal Diameter: 0.110”
Minimum bend radius: 1”
RF Loss: 15 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 10 Watts out
Price: $0.55/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
From Other Manufacturers:Belden - RF400
Andrew/Commscope - CNT400
Commscope - WBC400
Coleman - Signawave 400
Carol - DBRF400
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
A word of Caution...None of the Cables listed in this section are suitable for use in repeaters or other duplex applications
The galvanic dissimilarity of the AL foil and the CU braid accelerates oxidation which creates a non-linear junction within the outer conductor of the cable.
This non-linear junction becomes and RF mixing point.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Silver Plated Coax
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Do I need Silver Plated Cable?● Duplex Applications
○ In-band receiver active at the same time as one or more transmitter(s)
● High RF Power Levels● High Temperatures● Microwave Frequencies
Cables with silver =/= Low Loss cables
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-142Standard: M17/60-RG142
Center Conductor: 19AWG Solid
Nominal Diameter: 0.195”
Minimum bend radius: 2”
RF Loss: 7.9 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 20.1 Watts out
Price: $3.27/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-223Standard: M17/84-RG223
Center Conductor: 19AWG Solid
Nominal Diameter: 0.212”
Minimum bend radius: 2.25”
RF Loss: 8.8 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 18.1 Watts out
Price: $2.67/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-400Standard: M17/128-RG400
Center Conductor: 19AWG Stranded (19x32AWG)
Nominal Diameter: 0.195”
Minimum bend radius: 1”
RF Loss: 8.7 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 18.4 Watts out
Price: $3.24/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-214Standard: M17/75-RG214
Center Conductor: 13AWG Stranded (7x21AWG)
Nominal Diameter: 0.425”
Minimum bend radius: 6”
RF Loss: 4.1 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 31.2 Watts out
Price: $2.84/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-393Standard: M17/127-RG400
Center Conductor: 13AWG Stranded (7x21AWG)
Nominal Diameter: 0.390”
Minimum bend radius: 2”
RF Loss: 4.8 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 28.8 Watts out
Price: $9.38/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
RG-316Standard: M17/113-RG316
Center Conductor: 26AWG Solid
Nominal Diameter: 0.098”
Minimum bend radius: 0.5”
RF Loss: 17.5 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 6.6 Watts out
Price: $2.00/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Hardline
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Heliax Numbering● 1 - ¼”● 2 - ⅜”● 4 - ½”● 4.5 - ⅝”● 5 - ⅞”● 6 - 1 ¼”● 7 - 1 ⅝”
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
LDF Cable“Low Density Foam”
Replaced by AVA Cable
LDF4-50A
Center Conductor: 0.190” Solid
Nominal Diameter:0.625”
Minimum bend radius: 5”
RF Loss: 1.36 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 46.32 Watts out
Price: $1.98/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
FSJ CableFSJ1-50A
Center Conductor: 0.075” Solid
Nominal Diameter:0.290”
Minimum bend radius: 1”
RF Loss: 3.7 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 32.7 Watts out
Price: $1.27/ft.
FSJ4-50B
Center Conductor: 0.140” Solid
Nominal Diameter:0.530”
Minimum bend radius: 1.25”
RF Loss: 2.2 dB/100’ @400MHz
★ 50 Watts in + 50’ of coax = 38.9 Watts out
Price: $2.85/ft.
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Consideration Points
● Acceptable RF Loss● Diameter● Repeated Flexure or Vibration● Total cost
○ Cost of cable and connectors○ Cost of replacing in the event of a failure
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
Names To Know:
Coax: The Critical Link ©2018 Jeremy Breef-Pilz
References RG to M17 Cross Reference
Max. Attenuation, Power and Frequency for M17 Cables
Times Microwave Cable Properties Calculator
Watts to dBm Calculator
Coax: The Critical Link ©2018 Jeremy Breef-Pilz