Category Archives: HAM Radio

Articles that pertain to HAM Radio such as HF operation, contests, new equipment, etc.

Monitoring Outdoor Temperature with RTL-SDR

If you’re like me you’re interested in knowing the outdoor temperature.  If you’re also like me, the prospect of spending $$$ for a computer weather station doesn’t sound too appealing.  Once again, the wonderful $30 RTL-SDR dongle to the rescue!  In today’s blog post I will show you how you can use the RTL-SDR to intercept the wireless signals sent from your neighbors outdoor weather stations, and how to use these to know the weather around your home.

First, you will need an RTL-SDR dongle, connected to an antenna.  I am presently using my TV antenna to feed my RTL-SDR dongle, which is connected to my VMWare server and assigned to a virtual machine.

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SDR Based Flight Tracking

I recently had the need to track the arrival of a flight into the airport near my house.  Of course, I could use any of the online services available for this, but being a HAM radio operator, I wanted to track this data myself.  I discovered that with a $30 RTL-SDR dongle, this can easily be done.

First, I built a co-linear antenna for this.  This is a simple antenna made by connecting stub pieces of coax together.  I opted for a 4 element co-linear which is not the best configuration.  I will at some time build an 8 element and place it within a PVC pipe.  This is just a proof of concept.

Using the plans here I made a 4 element antenna.


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Ultra Cheap 440 MHz HAM Radio Yagi

I’ve recently been playing with a pair of low-power 440MHz UHF data transmitters (side note these are very cool and ultra cheap 100mW UHF radios) and needed to build a pair of 440 MHz directional yagi antenna to extend the range.


I stumbled upon this write up on Radio Reference about a guy who built a yagi antenna from old clothes hangers and a broom stick.

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Eastern Iowa Yeasu FT7900 Programming

Hello everyone, please find attached to this post my latest 2015 Programming File for the Yeasu FT7900 / FT8900 Radio.  This is in Chirp format.  This includes all repeaters I am aware of in eastern Iowa and western Illinois.

Covers Washington to Waterloo, Van Horne to Joliet.

Separate memory banks are used to keep each service and location separate for scanning.

Bank 1 = FRS / GMRS (RX Only)
Bank 2 = Air & Train (RX Only)
Bank 3 = Ham Simplex and Cedar Rapids/IC repeaters (incl Muscatine and SE Iowa)
Bank 4 = Ham Simplex and Quad Cities Repeaters
Bank 5 = Ham Simplex and Waterloo / NE Iowa
Bank 6 = Business and Hotels (RX Only)

Download 2015-08 FT7900 Programming KC0AKY

RTL-SDR Based LTE Signal Analyzer

Have you ever wanted to detect what network is installed at what tower?  screenshot_01Interested to see how a network upgrade or overlay is progressing?  Or, maybe you are interested in getting a better idea of the relative signal strength of multiple LTE networks, with a passive receiver?  If so, this is the blog post for you.

This post will explain how to build a custom application for the Kali Linux system which will allow you to use a RTL-SDR DVB TV tuner chipset to perform spectrum analyzer functions on LTE signals.  Using the E4000 chipset, I have decoded LTE signals in 700MHz, 800MHz, 1900MHz (PCS) and 2300MHz (AWS) frequencies. Continue reading