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EPISODE 2: Channel Scanning with FieldFox

RF Explained Episode 2 – Buckle up and join us on this exciting journey of FieldFox's channel scanning mode in action. Learn about channel power measurements, why they matter, and how to use a spectrum analyzer to overlay power data on GPS.


Hi! This is Kelly with the FieldFox handheld analyzer.

Today we are going to explore FieldFox's Channel scanning mode in 3 parts

  1. What is Channel Scanning
  2. Setting up the channel scanner
  3. Channel Scanning in action

So, what is channel scanning?

Essentially, the channel scanner measures the power of multiple channels simultaneously, which helps you identify issues with path loss, interference, and weak signal strength.

To understand channel power, it's helpful to think of it as the total power within an integrated bandwidth. I know, this may bring back haunted memories of Calculus. But don’t worry. Why calculate integrals when a spectrum analyzer can do the math for you? No more worrying about manually finding the area under the curve.

This is important for anyone who uses devices like smartphones, laptops, and Wi-Fi. No one wants to deal with dropped calls or slow internet. If your system isn't outputting enough power, your signal can be drowned out by noise, causing problems like decreased coverage, reduced reliability, and overlapping interference. On the other hand, if the power is too high, you may experience issues like non-linear performance, component damage, or even an outage.

The channel scanner mode on FieldFox makes it easy to understand your network's performance. With features like time interval logging and geotagging, you can easily overlay power data on a GPS map, so you can see exactly where your signal is strongest and weakest.

So, let's set up the measurement!

Make sure you have your GPS antenna. And, if you have a strong signal, this little guy works too.

The channel scanner can measure various wireless signals for up to twenty channels. For this example, I will keep it simple and track the coverage of 2 FM radio stations.

Channel power requires the input of four variables.

  1. Center frequency of the channel
  2. Integration BW
  3. Upper power limit
  4. Lower power limit

Once all the variables are in and the GPS coordinates are loaded, FieldFox is ready to log data. Zoom in on your location, and you can view the power data displayed on the map.

The Channel Scanner is ready to go. Let's collect some data!

Safety First. You ready?

As I start driving, you can see the power levels start to change. These are recorded on a scale from deep blue to dark red. The GPS pins get warmer as the power level increases. You can see the power levels of channel 1 are consistently higher than channel 2. But these are all within our acceptable limits of -80 to -40 dBm.

Here is a side-by-side example of two channels on a drive throughout the entire city. You can see how this tool could help visualize coverage tests and identify areas with interference issues.

Catch you next time!

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