David F4HTQ wrote:
"finally I do not wait for the weekend :)"
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The test method you described seemed simple enough to give it a quick go. Attached is a photo of the test set-up I used. One turn of wire attached to a Banana-BNC adapter and connected to CH0, hopefully similar to your description.
I pulled out the first ferrite core I could find and measured it. The initial curve from 100k-30M looked like junk below 1M and not enough definition at 30 MHz. I changed the range to 1M -100M. The core is definitely not type 43 and pretty broadband in nature. I measured two other cores just like it and their curves overlapped. Found identifying markings on the cores - Laird type 28B2400-000. Found the curves for Laird 28B on-line and have attached them.
The Laird 28B series is definitely broadband but not sure I could have identified my cores from the Laird curves without priori information. The NanoVNA curves for all three cores did match and I suppose I could build up a signature database and use it to sort unknown ferrites.
Thanks for giving me another idea for using the NanoVNA.
- Herb
