Being very busy at the moment I’ve had to restrict my scanner hobby to those modes that dump out a page full of data that I can take a peak at now and then, instead of the high maintenance method of constantly tuning around for something to listen to.

This has given hours of experimenting with a bunch of datamodes (received via SDR dongles) that where only ever previously received on my bigger physical radios. Its all been made more of an interesting challenge as I’m not completely setup with every antenna I’d like at my new location(yet).

poscag on rtl sdr

SDR Sharp Tuning Screen

Taking into account that things are not exactly the way I’d like them (for now), I’ve been sticking with the more stable, always on and very strong signal sources. One of the best of these has to be the transmissions from the pager networks, who by the very way they have to reach such a wide area, have a huge power output with most systems offering country wide coverage.

Equipment

Using a standard RTL dongle running on SDR Sharp and plugged straight into my PC, I take the audio directly from the computers system by using the ‘Stereo Mix’ option in the recording audio properties.

I run my SDR dongle on a 2 meter USB extension lead as it cuts back on a lot of the random RF hash thrown out by the computer.

And the Fun Begins….

Sound card decoders are great pieces of software that give almost anybody access to many of the datamodes being transmitted but can be a total nightmare to setup. Getting the input volume just right into the decoder can try the patience of even the calmness of people.

The higher the data rate, the more difficult it is to set the volume to reduce errors to a minimum. There is a bit more control with using SDR than your average physical radio as you can play about with the bandwidth a little more and changing this one factor can make a big difference to what you end up with on the screen.

The PDW software I’m using for decoding pagers is beautiful when you get the audio just right, its the process of finding that sweet spot that can drive you a little mad 🙂

After much painful experience I’ve discovered that eliminating all the decode errors is next to impossible but you can certainly get it working to a point where any faults don’t get in the way of understanding the messages.

The audio settings can also can slightly depending on what frequency your using, so be prepared to make little adjustments for each different pager channel.

Tip : Unless you have a computer set aside for pager decoding then your going to change the sound settings for other programs at some point. Write down what your working audio settings are and it’ll save you a whole lot of messing around next time you use the pager decoder.

Pager Decoder Output

Some of what you see at the output of the decoder are just system messages and are of no real interest (you’ll learn to ignore these over time) but there’s still a huge amount of ‘real’ messages to read.

PDW will allow you to scroll back through a mass of messages making it possible to leave the software running and come back later to take a look.

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