Or if you don't want to concern yourself with different slugs for different frequencies and power levels (other than UHF)...sell your Bird wattmeter and all the slugs and get a LP-100A which has NIST traceable calibration and typically reads +/- 3% of the power reading from 1 W to 3000W ....and you get peak or average reading as well as many other nice features... Call me biased -- because I have two of them...but if you want to learn more... http://www.telepostinc.com/lp100.html 73 de Greg-N4CC
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Tom W8JI Sent: Saturday, June 30, 2012 5:25 PM To: [email protected] Subject: Re: Topband: QRP and Bird 43 Watt meter help > Many years ago at 4U1ITU I found the Bird 43 grossly underestimated > the power output on 160, rather embarrassing at the temple of > regulation. If that was the case, they had a bad slug. The rating of the Bird 43 and standard slug is + or - 5% of full scale anywhere on the scale within the range of the slug, but it does not go far out of tolerance just 10% below the low end of the specification range. A 250-watt 2-30 MHz slug will read close to spec on 160 meters. If it is way off on 160, you can bet it is way off on 80 and 40 meters, too. - or + 5% means acceptable error is 12.5 watts low or high anywhere on the scale, although normally when freshly calibrated they are much closer than that. I would not expect a 250 watt slug to be more than 10-15 watts off on 160 meters, although the most common calibration failure is low reading. The low reading error almost always comes from the calibration pot making a high resistance connection to the wiper, meaning the slugs that go bad will age terribly low in reading. About 30% of my Bird slugs fail in ten years, despite very rarely being handled or used. People need to remember the accuracy specs, and use slugs that keep the meter well up the scale if accuracy is important. 73 Tom _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
