Darrell, Caution, The toroids should be wound as instructed - you may measure them, but please do not try to make the inductance equal that indicated in the manual/schematic because those inductance values are either what was measured on someone else's inductance meter, or they are approximate values. If you want to calculate exactly the inductance required, you must calculate the entire low pass filter design, and then be certain to measure the inductors at the frequency of use - and with a properly calibrated inductance meter - I would bet the MFJ259 could be off by as much as 20% until proven otherwise by measurement of standard inductors at various frequencies.
No Q-Dope or fixatives of any kind should be used for Elecraft kits unless specifically stated - I have never experienced any problems with toroids and have never used anything to hold them in place. One of the K2s I built is being used successfully as a mobile - in an 18 wheeler - check the QRZ.com listing for W4GNS if you have any doubts. 73, Don W3FPR > -----Original Message----- > > As I build my second K2, I want to try to measure the inductance of the > toroids with my MFJ-259. The MFJ manual has instructions on how > to do this. > Essentially one builds a series LC circuit and measures the resonant > frequency and then calculates the inductance. > > Has anyone tried this and have any tips or tricks to pass on? > > Am I correct in assuming I can adjust the value of inductance on a toroid > slightly by compressing or expanding the spacing between turns? > If so what > can I use to hold the turns in place. Friction is probably good > enough, but I > wonder about a few drops of something like Q-Dope. Comments? > > 73, > Darrell > -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.10.16/83 - Release Date: 8/26/2005 _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
