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## [Amps] RE : Ohmite thick-film resistor L measurement

 To: "'Dave Haupt'" , [Amps] RE : Ohmite thick-film resistor L measurement "hermans" Thu, 22 Dec 2005 00:20:44 -0000
 ``` KISS .......but here S stands for SMART. Jos on4kj Merry XMS and Happy 2006 to ALL -----Message d'origine----- De : amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] De la part de Dave Haupt Envoyé : mercredi 21 décembre 2005 22:28 À : amps@contesting.com Objet : Re: [Amps] Ohmite thick-film resistor L measurement Series L could hardly be easier in this case. You can even use your rig, assuming it's broadbanded. Use the 100 ohm resistor as a load. At low frequencies, it will measure SWR=2:1. Raise the frequency until you see the SWR rise to some convenient value at which you trust your measurement device - 2.5:1 or 3:1 for instance. Assume the rise is caused by series inductance. Now, plot the SWR=2.5:1 or SWR=3:1 circle as appropriate on the Smith Chart. Follow the Rnorm=2.0 line up from the X=0 line until you hit the SWR circle you've drawn. Read off the Xnormalized, and a few little multiplies and divides and you'll have the series inductance. Alternatively, an RF sig gen, a one ohm carbon comp 1/4 watter and a two-channel scope can do it the old-fashioned way by measuring V and I and dividing them. 73, Dave W8NF >>R.Measures wrote: >> ??? I need to find someone who can measure the L of an Ohmite type TAP >> 600W, 100Ω thick-film resistor. This resistor will be used for R-supp >> in a QRO VHF parasitic suppressor R&D project. >Unless the reactance is greater than about 650 ohms, you should be able >to use an MFJ or similar antenna analyzer -- it will tell you R and Z >(or L). Am I missing something? >-- >73, >Vic, K2VCO >Fresno CA >http://www.qsl.net/k2vco __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps ```
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