Thanks, this is interesting. I'm copy it here
Manuel; DL2MAN wrote:
I did a high resolution calibration with 5500 Points per Sweep between 1-50MHz. Every 9,9khz I have a calibration Point and a measurement point (averaged: every point measured 5x, the 2 points with biggest deviation get kicked and the remaining 3 get averaged).
Now 1 full sweep (for calibration and for measurement) takes about 10 Minutes....
As you can see below: The higher the Q gets, the more uncertainty is involved. But as before: All 3 curves were aquired with the same setup and settings, and the trend (for comparison) should be very clear.
High Resoultion Plot of Micrometals T37-2 (red):
Attachment:
InkedHighRes-1-50-T37-2_LI.jpg [ 96.97 KiB | Viewed 5159 times ]
High Resolution Plot of Micrometals T37-6:
Attachment:
InkedHighRes-1-50-T37-6_LI.jpg [ 130.83 KiB | Viewed 5159 times ]
And just for comparison and to underline my initial statement to avoid cheap chinese Toroids: High Resolution plot of Chinese 37-6 (Yellow) Toroid:
Attachment:
HighRes-1-50-chinese37-6.png [ 20.29 KiB | Viewed 5159 times ]
Quote:
Conclusion:
For 160m - 60m T37-2 is superior to T37-6
For 40m, they are equally usable
For 30m and higher T37-6 is superior to T37-2
And never ever use chinese Toroids exept for dummy loads
73 Manuel; DL2MAN
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