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Because of how narrow the bandwidth is on an air wound choke it needs to be spot on. Going from 5 turns of RG213 on a 4.25 inch core to 7 turns will move where it works from 26-28MHz down to 17-18MHz. Two turns and you have an almost 10MHz drop in the frequency it works on so half a turn can see you move the peak choking to above or below the 11m band quite easily.

Using ferrite rings and coax to make the choke, the peak choking bandwidth is 15-20MHz wide so getting it wrong by half a turn or so is not as critical as with an air wound.

OK let's go futher and do as I did 5T 4.25" and add 5 10 15 or 20 beads of 31mix from palmar or 18 to 24 inches of beads into the 5T's. Now what? Do I get BOTH narrow window 25Mhz to 30Mhz via 5T''s and adding beads oq what happen's? Just curious?

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[QUOTE="Heavy Metal, post: 526313, member: 42492"] Because of how narrow the bandwidth is on an air wound choke it needs to be spot on. Going from 5 turns of RG213 on a 4.25 inch core to 7 turns will move where it works from 26-28MHz down to 17-18MHz. Two turns and you have an almost 10MHz drop in the frequency it works on so half a turn can see you move the peak choking to above or below the 11m band quite easily. Using ferrite rings and coax to make the choke, the peak choking bandwidth is 15-20MHz wide so getting it wrong by half a turn or so is not as critical as with an air wound.[/QUOTE] OK let's go futher and do as I did 5T 4.25" and add 5 10 15 or 20 beads of 31mix from palmar or 18 to 24 inches of beads into the 5T's. Now what? Do I get BOTH narrow window 25Mhz to 30Mhz via 5T''s and adding beads oq what happen's? Just curious? [/QUOTE]

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