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Old January 5th 09, 06:30 AM posted to rec.radio.amateur.antenna
Jeff Liebermann[_2_] Jeff Liebermann[_2_] is offline
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First recorded activity by RadioBanter: Jun 2007
Posts: 1,336
Default The $1000 Power Measurement Challenge

On Sun, 04 Jan 2009 10:55:21 -0800, Richard Clark
wrote:

well-heeled Ham "could" achieve the determination of RF power to
within 0.1dB of its actual value.


RF power at 14.1MHz or including all the spurs and harmonics that come
with it? They're probably not much of an issue with the typical ham
100watt xmitter, but certainly are a problem with QRP hardware that
sometimes has no output LPF of any kind.

Also, do you want the 50 ohm terminated RF power, or measured through
the line to a random antenna load?

3. That power is 10mW.


0.1dB is about 2.3% accuracy. Plenty of lab grade hardware around,
but none with 10mw full scale sensor:
http://www.bird-electronic.com/products/subcategory.aspx?sid=79

However, with a $1000 prize, I guess something cheaper will be
required. How about a:
http://www.ohr.com/wattmeter.htm
Not anywhere near as accurate as you want, but for a single 14.1Mhz
frequency, I would have no problem using a properly calibrated signal
generator to create a calibration chart. Also, some environmental
isolation and a temperature compensation chart will be useful.

Ummm..... why do you need such accuracy? Is there some kind of QRP
ultra low power contest that I don't know about? Amateur metrology?

Send the $1000 to the address below.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558