Exhibit P.pdf
PDF 4 MB Posted
- Attached to
- Elementary Gymnasium Wood Flooring
- Solicitation number
- S-P27057-00003878
- Issued by
- Multnomah County, Oregon
About this file
This is a technical exhibit document from the Oregon Department of Transportation (ODOT) Statewide Mobility and Operations Traffic Program (SMOTP) providing reference guidance on Anritsu sweep display examples and acceptable parameters for feedline testing and antenna system evaluation. The document serves as a technical reference guide for field technicians conducting quality assurance testing on communication system infrastructure, specifically addressing distance-to-fault measurements, return loss analysis, cable loss assessments, and antenna performance evaluations. The exhibit outlines acceptable versus unacceptable sweep profiles across multiple testing categories, including feedline open/short conditions, load conditions, cable loss measurements, and system-level antenna return loss testing. All sweeps must meet a minimum return loss threshold of at least 14 dB (1.5:1 VSWR) within the antenna passband to be considered acceptable, with the document noting that return loss values above this threshold indicate unacceptable antenna performance.
The technical guidance presented in this exhibit emphasizes the importance of careful interpretation of sweep data, acknowledging that acceptable performance is influenced by antenna type and environmental factors such as nearby radio frequency interference. The document specifies that negative loss readings—indicating gain—represent setup errors in the Anritsu equipment and render all sweeps for that site suspect. The exhibit includes sample antenna sweep profiles for the most commonly installed antenna types used in ODOT operations, providing field technicians with reference standards for comparison during quality assurance testing. This document functions as a training and reference resource to ensure consistent, accurate evaluation of mobile communication system infrastructure across Oregon's transportation network.
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Other files
| File | Type | Posted |
|---|---|---|
| Wood gym floor spec.docx | DOCX document | |
| RFQ for ES Gymnasium Wood Flooring project.docx | DOCX document |
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Text version
ODOT SMOTP Appendix
Anritsu Sweep display examples
Feedline Distance to Fault Open- Acceptable Sweep- Sweep shows gradual rise up to the end of the Feedline (open or short). The display shows the end of the cable at 67.88’.
Feedline Distance to Fault Open - Acceptable Sweep- Sweep shows gradual rise up to the end of the Feedline (open or short). The display shows the end of the cable at 72.97’. Notice that “smoothing” is used by the Anritsu on this display.
Feedline Distance to Fault Open- Suspect Sweep- Sweep shows gradual rise up to the end of the Feedline (open or short) EXCEPT for the high peak a~9’. This could be a kink, bad connector, etc in the line. Further investigation including inspecting the cable around that distance from the test device is necessary.
Feedline Distance to Fault Load- This sweep is for future use. It will be very similar to the DTF (short/open) reading, but will be affected the return loss of the load.
Feedline Return Loss Load- Acceptable Sweep- RL is BELOW 30 dB, and the trace is relatively smooth with no wild deviations.
Feedline Return Loss Load- Acceptable Sweep- RL is BELOW 30 dB, there are deviations. Feedline length can impact the return loss vs. frequency.
Feedline Return Loss Load- UNACCEPTABLE Sweep- RL is not below 30 dB, there are serious deviations in the RL.
Loos to
Feedline Cable Loss to Open (or short)- Acceptable sweep- This is a sweep that needs to be looked at carefully. This is a 7/8” Heliax that is ~100’ long, with a ½” jumper at the end. Factory data says .449 dB of loss for 100’ at 150 MHz, adding 4 connectors and ~10’ of jumper, this is OK.
Feedline Cable Loss to Open (or short)- UNACCEPTABLE sweep- If the sweep show negative loss (as in gain), thre is an error in the Anritsu setup. This should NEVER be acceptable, and all other sweeps for that site become suspect!
Feedline Return Loss to Antenna (System)- Acceptable sweep- This is a somewhat subjective sweep at times. It is highly influenced by the antenna type, and some environmental factors. This is a good sweep of a Bluebird antenna- All sweeps must meet at least 14 dB (1.5:1 VSWR) within the passband of the antenna to be acceptable. Of the two sweeps below, sweep one is the antenna only in a quiet RF environment. Sweep two is installed on Lime Hill in a high RF environment. Both pass, but you can see the effect of nearby RF, feedline, etc.
Feedline Return Loss to Antenna (System)- Unacceptable sweep- This is a ANT-150 antenna that is bad.
Return Loss is above 14 dB.
Feedline Distance to Fault System- This sweep is for future use. It will be very similar to the DTF (short/open) reading, but will be affected the return loss of the antenna as well. In this example, M1 is the end of the feedline, the rest up to M2 is the Anritsu trying to “interpret” the elements of the Bluebird antenna connected to the feedline.
SAMPLE ANTENNA SWEEP PROFILES- Here are sweep profiles for the most used antennas we are installing for reference….
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