
Listening to 700 MHz Simulcast public safety radio cheaply - wolframio
http://kb9mwr.blogspot.com/2017/07/listening-to-local-700-mhz-simulcast.html
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FTA
This sort of setup can also be used to monitor aircraft squelches. I got a few
Raspberry Pis during a B1G1 sale, so I have one of these setups at work and at
home. I like watching the planes as they take off from the local airport and
queue up for arrival, and also seeing the nightly freight flights.

More info here:
[http://flightaware.com/adsb/piaware/](http://flightaware.com/adsb/piaware/)

You can feed into sites like Flightaware and FlightRadar24 and get accounts
with them that normally cost a lot for free.

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fapjacks
Yes! I've been feeding into FlightRadar24 for some time to sate my strange
curiosity with aviation. It's also Swedish company that is pretty accessible
if you have questions or suggestions (and incidentally is hiring). I don't
work there, just a big fan.

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gravypod
If people are interested in listening to signals I'd recommend checking out
the ELF to VLF bands. You can, in most cases, build a receiver that operates
directly on your system's sound card. These lower frequencies largely present
an antenna building challenge but there's lots of interesting things down at
those frequencies. Submarines, hams, and space weather.

The HF to EHF bands are fun but the lower frequencies, which are mostly
ignored, are just as much of a gold mine for fun projects.

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3uh5weutwehow
If you do not have one, get yourself an RTL-SDR today. This is a cheap ($10)
way into radio and you will be impressed with what you can do.

From radio scanning to public safety radio to airplane tracking all with free
software!

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squarefoot
Agreed. While I love the analog scales on old radios and the glowing light
behind the dials, SDR is so fun, portable and cheap to play with. After
wetting the toes with repurposed cheap TV dongles, I'd suggest to get a dongle
from rtl-sdr.com (satisfied customer, no affiliation whasoever). I have two of
their dongles and while they're priced almost in the same league of the TV
ones ($20 dongle alone, or $25 with 2 antennas) the performance wrt
sensitivity and noise floor is remarkably better. Next purchase then will be a
upconverter to get the interesting stuff aired in the HF bands. There are ways
to convert dongles into direct sampling receivers for these bands; I can't
report on their workings as I never tried them but without any filtering on
the input I believe the performance won't be that good, at least compared to a
full blown converter with filtering at the front end stage.

