I recently measured, using lab grade equipment, 16 powdered iron toroid inductors of approximately 2uH and 16 of approximately 9 uH, at a fixed frequency. Details can be seen at http://www.cliftonlaboratories.com/may_2011.htm under 15 May 2011 entry.
The purpose of the exercise was to assess the inductor-to-inductor variation, recognizing that 16 inductors, wound by the same person, and from one batch of cores, is likely to show less variation than if 16 different builders wound one inductor each, and if the cores were from random manufacturing batches. The inductance spread was 10% for the 2uH parts and 8% for the 9uH parts. Jack K8ZOA On 6/1/2011 1:25 PM, Eric Swartz - WA6HHQ, Elecraft wrote: > Stick with the correct number of turns. The inductance listed is a > nominal calculated value and will vary from core to core, and with the > frequency used to measure the inductance. > > We also see a wide variance in inductance measurements between different > instruments based on their differing test frequencies. > > It -is- important that you confirm you are using the correct core, color > etc. > > 73, Eric > > > On 6/1/2011 10:20 AM, rhapak wrote: >> Hi all! >> In the K2 manual it says to wind the toroids with the amount of turns >> specified and not to alter the windings to get the inductance specified in >> the parts list. >> I notice that many of my toroids do not measure near the stated inductance >> in the parts list but are wound with the specified amount of turns and would >> just like to know why?? >> >> Thanks in advance, >> Rod >> VA3 ZVT >> >> -- >> View this message in context: >> http://elecraft.365791.n2.nabble.com/K2-Toroids-not-measuring-correct-inductance-tp6427961p6427961.html >> Sent from the Elecraft mailing list archive at Nabble.com. >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
