ARRL Testing of Broadband Over Power Line Systems
Download
1 / 55

ARRL Testing of Broadband Over Power Line Systems Ed Hare, W1RFI ARRL Laboratory Manager 225 Main St Newington,CT 06111 - PowerPoint PPT Presentation


  • 204 Views
  • Uploaded on

ARRL Testing of Broadband Over Power Line Systems Ed Hare, W1RFI ARRL Laboratory Manager 225 Main St Newington,CT 06111 [email protected] 860-594-0318. Background. ARRL is the US national association for Amateur Radio Represents Amateur Service in regulatory and industrial venues

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'ARRL Testing of Broadband Over Power Line Systems Ed Hare, W1RFI ARRL Laboratory Manager 225 Main St Newington,CT 06111' - borka


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Slide1 l.jpg

ARRL Testing of Broadband Over Power Line SystemsEd Hare, W1RFIARRL Laboratory Manager225 Main StNewington,CT [email protected]


Background l.jpg
Background

  • ARRL is the US national association for Amateur Radio

  • Represents Amateur Service in regulatory and industrial venues

  • ARRL’s interest in BPL is related only to its EMC aspects

  • Other than EMC issues, BPL should be allowed to succeed or fail on its own merits

  • Amateurs are often early adopters of new technology


Scope of arrl testing l.jpg
Scope of ARRL testing

  • ARRL staff have done testing in 12 cites where BPL is located

  • Other radio Amateurs have done testing in several other areas

  • ARRL’s testing capability has been evolving over time, so the nature of testing has also varied from system to system

  • ARRL testing done for EMC assessment, not for compliance purposes


Types of arrl testing l.jpg
Types of ARRL testing

  • Computational, mainly using NEC-4

  • Interference assessment

  • Site survey

  • Measurement of noise floor

  • Measurement of ambient signal levels

  • Relative measurements of noise-floor degradation

  • Field-strength measurements


Measurement of noise floor l.jpg
Measurement of noise floor

  • Ambient levels of man-made noise can range down to –20 dBuV/m at HF-station antennas

  • It is not possible to measure this level with spectrum analyzer and typical EMC antenna

  • Such measurements, even with active loops, are really measuring the noise floor of the test equipment

  • Communications receivers and real-world antennas are much more sensitive than EMC test equipment

  • To measure ambient levels, as a minimum, an EMC receiver and 8-foot monopole antenna, tuned to resonance with inductive loading, would be needed.


Receivers and spectrum analyzers see the world differently l.jpg
Receivers and spectrum analyzers see the world differently

  • Sensitivity

  • Antenna gain

  • Overload

  • Those who use test equipment to analyze the EMC aspects of BPL will see the results differently than radiocommunications users




Calculations l.jpg
Calculations

  • Primarily done with antenna modeling

  • No power-line model can represent actual real-world conditions

  • However, models can be used to determine principles behind how power lines radiate as antennas

  • ARRL used EZNEC Pro with NEC-4 method-of-moments electromagnetics calculation engine


Areas investigated l.jpg
Areas investigated

  • Gain of power line as antennas

  • Pattern of radiation pattern

  • Near-field E and H fields

  • Standing wave of emissions along power line

  • Relationship between E and H field

  • Distance extrapolation


Antenna gain and pattern l.jpg
Antenna gain and pattern

  • Gain of power-line antenna ranged over a range of approximately –20 dBi to +10 dBi

  • Varied with frequency, programmed losses, feed-point method, number of phases and spacing of the lines

  • Actual gain is not all that important, because the limiting factor is the permitted emissions level

  • Pattern shows that below 30 MHz, in the far field, most of the energy from a low horizontal antenna of any type is radiated upward


Fields near large radiators 14 mhz 30 meter 3 meter ratio 16 db l.jpg
Fields Near Large Radiators – 14 MHz30 meter/3 meter ratio 16 dB



Field testing typical test fixture23 l.jpg

AntennaAH Systems loopor ¼-wave mobile whip

0-70 dB Step Attenuator

ESH-2 EMC Receiver

Field testing – typical test fixture

A

AntennaAH Systems loopor ¼-wave mobile whip

B

0-70 dB Step Attenuator

Icom PCR-1000 Receiver

Laptop P.C.Windows 98Soundcard



Measurements of field strength in areas where bpl is deployed vendor and city location not included l.jpg
Measurements of field strength in areas where BPL is deployed(vendor and city location not included)









Fcc limits were apparently exceeded by at least 22 db in this system l.jpg
FCC Limits were apparently exceeded by at least 22 dB in this system:

The test fixture and measurement software made the following measurements, estimated as quasi peak field strength in a 9 kHz measurement bandwidth. These data are not extrapolated to distance.

3.52 MHz:

69.2 dBuV/m

68.7 dBuV/m

69.1 dBuV/m

69.0 dBuV/m

70.9 dBuV/m

Average: 69.4 dBuV/m


Other detailed reports l.jpg
Other detailed reports this system:

  • Raleigh, NC

  • Cedar Rapids, IA

  • Cottonwood, AZ

  • Cape Girardeau, MO

  • Manassas, VA

  • Emmaus, PA

  • ARRL CD


Bring the mountain to mohammed l.jpg
Bring the mountain to Mohammed this system:

A number of BPL manufacturers have taken out experimental licenses. One of the conditions of their license is that they file 6-month reports with the FCC, showing the measurements they make to determine compliance with the emissions limits. The following are from some of their reports, or represent an ARRL analysis of same.


To be done l.jpg
To be done this system:

  • More measurements of roll off vs distance

  • Levels vs height

  • Extrapolation (a distance vs height issue)


Video l.jpg
Video this system:


Q a a k a stump the speaker l.jpg
Q&A this system: a.k.a. Stump the Speaker


Slide55 l.jpg
MORE INFORMATION this system: Ed Hare, W1RFIARRL Laboratory Manager225 Main StNewington,CT [email protected]60-594-0318


ad