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Any integrated circuit that works as the old tone decoder but for RF ?
Posted: Sun Mar 10, 2019 12:38 pm
by Externet
Hi.
Do you know of an IC like the NE567 audio tone decoder (detector) but for RF ?
Looking to detect the presence of 11MHz or 130MHz, turning a LED on.
Re: Any integrated circuit that works as the old tone decoder but for RF ?
Posted: Mon Mar 11, 2019 3:07 pm
by haklesup
I don't think so, most RF signals have digitally encoded data that do the work (or at least AM or FM modulation in an old system). Getting an FCC license to use a bunch of broadcast frequencies in an interference scheme seems unlikely.
If you just want to detect either of these frequencies, then a radio receiver tuned to each and output directed to the LED somehow instead of a speaker or data channel seems like what you want.
11Mhz is shortwave, maybe you can find an old radio. 130Mhz is just beyond FM, maybe you can tweak an FM receiver to extend the range. I see some links in that direction. They are in different bands, I doubt you can find one solution that can receive both but maybe.
What uses these frequencies? What kind of modulation is the source signal
Re: Any integrated circuit that works as the old tone decoder but for RF ?
Posted: Mon Mar 11, 2019 4:36 pm
by Externet
Thanks, haklesup.
Yes, bought broadcast FM receiver kits that use a TA2003 receiver chip, modified for 118 - 138MHz Rx and are working very well, (with distorted audio from FM demodulation that I do not care).
Ordered AD8307 chips to experiment if those detect 10.7MHz at the chip IF node hopefully telling me there is carrier presence but have not arrived yet. And ignore if there is a better way/choice.
Uses... 10.7 MHz IF and airband AM.
Re: Any integrated circuit that works as the old tone decoder but for RF ?
Posted: Mon Mar 11, 2019 4:58 pm
by Janitor Tzap
Hmmm.......
Your trying too make your own home brewed "Bug Detector" huh.
Or are you trying to make a "WIFI HOT SPOT Detector".
Well, there are plenty of differing schematic's out there.
Signed: Janitor Tzap
Re: Any integrated circuit that works as the old tone decoder but for RF ?
Posted: Tue Mar 12, 2019 12:38 pm
by haklesup
Modern Bugs and WiFi hover near 2.4Mhz so its something else or older tech.
maybe you can find a used Spectrum analyzer in an affordable range. here is an interesting Cell phone spectrum analyzer hack and product
https://www.youtube.com/watch?v=zu-K1Sslw1Q
https://www.youtube.com/watch?v=5LC7YYA6s4A
Re: Any integrated circuit that works as the old tone decoder but for RF ?
Posted: Tue Mar 12, 2019 5:56 pm
by CeaSaR
Shortwave and the old Air band.
You could set up some divide by chips and feed them into the ADC pins of a microcontroller, sampling the pins at X intervals, to see when the signal comes through. Then the code can compare the frequency to a range, and if it falls within, it can output a high to turn on the required LED.
Or
Set up the divide by chips to get the frequencies down, build a set of oscillators for the required lower frequencies, then feed them into AND gates. When they are both present, the Output turns on and the LED can be lit.
Any of this sound plausible?
CeaSaR
Re: Any integrated circuit that works as the old tone decoder but for RF ?
Posted: Wed Mar 13, 2019 4:09 am
by dyarker
haklesup, make that 2.4GHz for Wi-Fi.
Cheers,
Also, 118MHZ to 137MHz is for air traffic control.
Re: Any integrated circuit that works as the old tone decoder but for RF ?
Posted: Wed Mar 13, 2019 5:46 am
by jwax