Total posts : 45366
its too dark out to take photos this time.
i used a mystery diode i believe to be germanium. it has glass body and one green stripe on the cathode side. i put the 104 capacitor on the anode side of the diode and put them both between the two leads of the coil.
i taped the field strength meter’s antenna in a spot 1ft off the ground and about 8ft from the amt3000 antenna.
i used my fluke 117 multimeter set to the mV DC setting. am i right to have it on the DC setting?
with the transmitter turned off it read 0.5mV. with the transmitter turned on and the coil way out of tune it also reads 0.5mV. the tapping the coil at the point i know to give the highest peak voltage (usually 10.5V, but it varies throughout the day) caused the meter to fluctuate between 3.6 and 4.1mV. most of the time it was at 3.6mV. the points around this tap (which i believe drop the peak voltage down to around 8 or 9V) showed 2mV on the meter.
conclusion: this method is much easier to read than the oscilloscope method (and it is way more convenient than lugging around a huge oscilloscope). however it is annoying to not be able to verify the peak voltage at the same time (i only have one multimeter).
i am curious why the values picked up would be so different (3.6mV vs 700mV). its too dark outside to do any more testing tonight but tomorrow i am going to try elevating the field strength meter’s antenna to be about parallel with the antenna. currently it is slightly below the antenna.
ps- i have a question about the peak voltage reading from the probe points on the amt3000. what exactly is that measurement called and what is it actually measuring? all i know is that higher is better and that it has something to do with resonance and how much power is being coupled to the antenna.
edit: fixed some grammar.