JohnAnonymous
New Member
I'm very new to electronics, but have always been into making things. Recently decided to try a DIY metal detector I found on the net. Fo far, everything from making the PCB to wiring everything together has gone fine.
The plan had two coils - a detector coil and a reference coil. The goal as I understand it is to have these at the same or very nearly the same frequency. I picked up a Radio Shack multimeter (my Fluke wouldn't go beyond 50 kHz) to measure the frequency of each.
I woung the large detector coil - it reads 96.5 kHz. I wound the smaller reference coil using a wood dowel - 156.3 kHz. I removed some wire from the smaller coil and remeasured - 121.0 kHz. Removed a little more wire - 0 kHz.
I hooked the larger coil up to the same circuit, and it reads fine. I have triple checked my connections, re connected the large coil at least 3 more times (always works) and have finally succumbed to scratching my head while staring at the coil.
I can rewind the coil (after a trip to Radio Shack for more 26 g wire), but I can't figure out why a simpe wire wrapped around a dowel would suddenly not have a frequency at all.
Can anyone shed a little light as to why this might happen?
The plan had two coils - a detector coil and a reference coil. The goal as I understand it is to have these at the same or very nearly the same frequency. I picked up a Radio Shack multimeter (my Fluke wouldn't go beyond 50 kHz) to measure the frequency of each.
I woung the large detector coil - it reads 96.5 kHz. I wound the smaller reference coil using a wood dowel - 156.3 kHz. I removed some wire from the smaller coil and remeasured - 121.0 kHz. Removed a little more wire - 0 kHz.
I hooked the larger coil up to the same circuit, and it reads fine. I have triple checked my connections, re connected the large coil at least 3 more times (always works) and have finally succumbed to scratching my head while staring at the coil.
I can rewind the coil (after a trip to Radio Shack for more 26 g wire), but I can't figure out why a simpe wire wrapped around a dowel would suddenly not have a frequency at all.
Can anyone shed a little light as to why this might happen?