Timeline for Detect presence of 12MHz squarewave without oscilloscope
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 1 at 15:12 | vote | accept | dragoncoder047 | ||
| Apr 1 at 15:12 | comment | added | dragoncoder047 | I got an FM radio and tuned it to a "silent" station, and then unplugged the wire. Instant static. Plugged it back in the static went away. Looks like the signal is OK :) | |
| Apr 1 at 15:09 | comment | added | John Doty | Or get a cheap shortwave radio and tune to 12 MHz. | |
| Apr 1 at 13:40 | comment | added | glen_geek | Yes, an unmodulated carrier produces no audio. Many FM receivers include a squelch circuit that acts like a "mute" between stations, so it can be difficult to tell if you have no audio due to a bare carrier, or the receiver is muted due to squelch. Quickly attaching/detaching the antenna should cause an audio disturbance in the receiver. Or moving the two apart far enough will cause noise, or de-activated squelch. | |
| Apr 1 at 13:35 | comment | added | Justme | @dragoncoder047 As there is no modulation, there is only a carrier which the radio should detect and say there is a signal. The audio is just silence. | |
| Apr 1 at 13:29 | comment | added | dragoncoder047 | The frequency is not changing, so there is no "FM" modulation. What should I be listening for on the fm radio? (BTW, your guess of 12MHz was exact.) | |
| Apr 1 at 13:01 | history | answered | glen_geek | CC BY-SA 4.0 |