TECH: Big Litz 1162/46 and 1200/46 tested on HP Q meter

Steve Ratzlaff

Here are the results of testing 1162/46 Litz (pink color, from eBay seller Ming) and 1200/46 Litz (blue color, from eBay seller in Canada, same as blue 1200/46 Litz from Chinese eBay seller) on my HP 4342A Q meter. Each was wound as a solenoid on a low loss styrene plumbing coupler. As many turns as would fit on each coupler was wound--the 1200/46 being slightly fatter, one or two turns fewer were wound for that coil. 163.5 uH for the 1162/46; 152.5 uH for the 1200/46. The Q meter's variable cap goes to 475 pF, so about 590 kHz was the lowest frequency tested that would resonate the coil.

In summary, the 1162/46 Litz has higher Q up to about 1300 kHz--quite a bit higher, especially at the low end. Above that both coils are closer in Q.

Note this is purely an "unloaded Q" test, for the coil all by itself. For use in a Ferrite Sleeve Loop there of course are other factors--the Q of the ferrite material and surrounding material, the Q of the tuning capacitor, and probably other factors. I can't positively say a higher Q coil leads to a better-performing (more sensitive and/or sharper tuning) FSL, but theory says that is so. Gary DeBock's A/B comparison tests on real signals with real FSLs indicates this is so, as well.


Steve Ratzlaff AA7U

1162/46 Litz coil, unloaded Q test

590 kHz 1652 Q

700 kHz 1676 Q

800 kHz 1650 Q

900 kHz 1598 Q

1000 kHz 1524 Q

1100 kHz 1435 Q

1200 kHz 1322 Q

1300 kHz 1152 Q

1400 kHz 797 Q

1500 kHz 827 Q

1600 kHz 873 Q

1700 kHz 813 Q


1200/46 Litz, unloaded Q test

590 kHz 1190 Q

700 kHz 1266 Q

800 kHz 1293 Q

900 kHz 1296 Q

1000 kHz 1274 Q

1100 kHz 1228 Q

1200 kHz 1122 Q

1300 kHz 1052 Q

1400 kHz 924 Q

1500 kHz 847 Q

1600 kHz 808 Q

1700 kHz 756 Q

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