Equis
Premium
join:2005-03-18
Australia
| How to measure EIRP
Hello
I would like to know exactly how much power output some of my links are.
Some I need to squeeze every db I can get.
Can I trust what the manufacture says the card will do?
Is there a gadget to measure whats at the tip of the antenna?
Thanks  |
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AMD Phreak
Please do the needfull
Premium
join:2003-12-14
| You'd use an RF watt meter at the antenna port on the radio and take a measurement there, and then add the antenna gain from the manufacturer minus off connecting losses. You could take it one step further and make your measurement at the coax cable before it connects to the antenna. |
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John Galt
Am I Coming or Going?
Premium
join:2004-09-30
Oceanside, OR | reply to Equis
In-line...
»www.praxsym.com/t-meter.html
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A is A |
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EMC_guy
join:2007-10-13
Sharbot Lake, ON
 ·Rogers Hi-Speed
| reply to Equis
said by Equis  :I would like to know exactly how much power output some of my links are. You could do this at any open-air test site (OATS) for a nominal fee.
Otherwise for in-situ EIRP measurements, you use a calibrated log-periodic antenna hooked up to a power meter and located in the far field along the main lobe. For 2.4Ghz, measure minimum 10 meters away. Even then you may need a claibrated attenuator to lower power level to the acceptable range of the meter. |
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LLigetfa
join:2006-05-15
Fort Frances, ON
| For comparisons, you could do side-by-side tests with a known value and compare the RSSI at both ends. If you are looking for test results that come with a get-out-of-jail-free card, it would take expensive gear.
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Strange as it seems, no amount of learning can cure stupidity, and formal education positively fortifies it. -- Stephen Vizinczey |
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viperm
Carpe Diem
Premium
join:2002-07-09
Winchester, CA
| reply to John Galt
We use this unit all the time. Best bang for the buck!!!
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EMC_guy
join:2007-10-13
Sharbot Lake, ON
·Rogers Hi-Speed
| Anyone wishing to measure 802.11a/g TX power please read this post and follow the Praxsym and Anritsu links:
»Re: Gain of mini pci card in dBm
Praxsym is not suitable for accurate OFDM power measurement. You can buy an used professional quality RF power meter (Anritsu, Agilent, Keithly, etc) for much less. These are sold off by test labs all the time as they acquire better units. |
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rfnut
Premium
join:2002-04-27
Fisher, IL | reply to John Galt
I thought they were out of business. Last time I walked uptown, I could of swore the sign was gone off the building. Maybe the last storm got it. |
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