On 9/2/2018 3:15 PM, Jim Bromley, K7JEB wrote: > http://coil32.net/online-calculators/ferrite-rod-calculator.html > > I used #8 wire as an approximation to 2 - #10's and > came up with 174 uH.
And that's way too high. Using #4 wire as an approximation to 2 - #10's and walking the calculation up to a 6.5" coil on the 7.5" core gives me N = 32 turns and L = 82 uH. BTW, that Al = 49 is in millihenries/1000 turns because it's a ferrite, so the desired inductance has to be specified in millihenries. For L = 0.082 mH, the number of turns N is: N = 1000 x SQRT( L / Al ) = 1000 x SQRT( 0.082 / 49 ) = 41 turns which is almost in the ballpark. 82uH = 927 ohms at 1.8 MHz. Just cram as many windings on the rod as you can get and be done with it ;-) k7jeb _______________________________________________ Boatanchors mailing list [email protected] https://puck.nether.net/mailman/listinfo/boatanchors
