Oznog
Active Member
I would like to be able to detect when a nearby transmitter in the 108MHz-137MHz range (aircraft radio) is transmitting. The signal should be quite strong, in fact circuit sensitivity must be low because we don't want to detect the signal from another transmitter or RF noise. I don't need to demodulate the audio out of the signal- no, this is just a cheap on/off switch that lights up when the nearby transmitter is on. This needs to be a simple RF detector without a commercial antenna or anything. It's a plastic case so an on-board antenna should be possible and highly desirable. I might need to make an installation that does have an external antenna option but if so it's going to need to be a pretty cheap implementation.
Hmm... one problem that occurs to me is that I need to detect a nearby transmission anywhere in this range, but a very low-Q receiver, even with low sensitivity, might have trouble with broadband noise over this whole range having the same total energy as a strong single-channel transmission, yet a simple receiver would not be able to analyze it based on channel energies. Well, actually, I should clarify- a dsPIC30F is involved in the circuit anyways. It does have an impressive ADC and mathematical analysis capabilities, but I'm not sure what its abilities are to analyze the RF band like this.
What are my options here?
Hmm... one problem that occurs to me is that I need to detect a nearby transmission anywhere in this range, but a very low-Q receiver, even with low sensitivity, might have trouble with broadband noise over this whole range having the same total energy as a strong single-channel transmission, yet a simple receiver would not be able to analyze it based on channel energies. Well, actually, I should clarify- a dsPIC30F is involved in the circuit anyways. It does have an impressive ADC and mathematical analysis capabilities, but I'm not sure what its abilities are to analyze the RF band like this.
What are my options here?
Last edited: