Post by W6JHB / Jim on Jun 1, 2020 19:16:55 GMT -5
I'm building a half-sized 20 meter Yagi from plans I found on the Internet. It has a driven element and a reflector, each with two center-mounted coils. The coils are to be wound with 32 turns of insulated #22 AWG on 1/2" OD PVC. The article indicates that the resulting coil will be about 8.5 uH. I tried two different manufacturers #22 wire and with my AIM4170C I get about 11 uH every time. It's in the ballpark, but I'm wondering why mine is higher than what was predicted / expected.
To measure, I soldered two 10" lengths of #14 insulated wire to the inside of a PL-259 and connected alligator clips on the free ends. I attached the clips to each end of the coil and ran a scan with the Setup set to Inductance, set for 14.0 - 14.2 MHz. The coil was hanging in free space, off the edge of my desk.
Am I doing something wrong? Is there a better way to measure this inductor?
Tnx, Jim / W6JHB
To measure, I soldered two 10" lengths of #14 insulated wire to the inside of a PL-259 and connected alligator clips on the free ends. I attached the clips to each end of the coil and ran a scan with the Setup set to Inductance, set for 14.0 - 14.2 MHz. The coil was hanging in free space, off the edge of my desk.
Am I doing something wrong? Is there a better way to measure this inductor?
Tnx, Jim / W6JHB