Qtmm AFSK1200 Decoder - Getting started

Hey

This is my first step by step guide to getting started using Qtmm AFSK1200 Decoder. I am not a expert on this software but it is one of the most straight forward way to get started with it. One of the main reasons to use Qtmm AFSK1200 Decoder is its good started in to understanding what a APRS packet looks like. Also it can be useful for testing a new APRS set up on low power.

Lets get started

Items you will need:

• A computer / laptop
• Sound card (can be a built in) with a line in / microphone socket (often a pink socket)
• A 2M radio set to 144.800MHZ. Also it must have a speaker socket. 
• A audio lead. For example for a FT-7800 its a 3.5mm jack to 3.5mm jack. 
• A copy of Qtmm AFSK1200 Decoder. 

First Step
First off we will need to download a copy of Qtmm AFSK1200 Decoder. Once we have downloaded it we will need to unzip it to run the program. *This step i will not screen shot as i do not feel it adds anything to this article.

Step Two

As we can see we now have a folder called QTMM 1.0.37win32. If we go in to it we have the following files.

Step three

To run the software we going to click the afsk1200dec icon. A box like this will pop up so simply click "Run"

Step Four

A box like the one shown below will pop up. Now we need to connect the radio to the computer. For this you will need to use the line in / microphone in socket on your laptop or computer. Simple then connect the other end in to the Radio speaker out.

Step Five

You will need to select the audio device on your computer. If you never adjusted your audio just simply select "Default"

Step Six

Now press the "play" icon next to the drop down to start picking up the packets. As you can see the sound meter bar to the "Right" is showing Red. You will need to adjust your sound levels down so it sits as close to the green as you can. I found on my FT-7800 that i barely had the sound up on the radio.

Now you need to just wait for someone to transmit some packets. At time of writing i did not have a antenna that i could use for picking up signal on. If all goes well you should see stations flowing in the software. 

Tips

• If you not getting any packets try turning the audio up a bit
• Leave it running for a few hours
• Visit APRS.FI to see if there are any stations near you.

New antenna

Last night i got the X50 collinear antenna up on to the main mast. This is fitted on a Z shape bar so it sits away from the main mast slightly. With help with the help of my YL we got the antenna up and on the mast just before the light went. Testing so far has been promising and i am just awaiting some switches to run the antennas so i can share it with the other radios.

Maintance

Just to let people know my 2e0emo APRS RX will be down for a few days due to safety as i work on the main mast. Hopefully this will improve the coverage and the signal in the area

Waiting game

So i am currently left to help the other half sort her licence out. I wish the RSGB would have a licence checker to see if she has been added on to the Ofcom website so i know when i can put her though the site. Oh the funs of the wait as her handheld is here waiting to be picked up from mine by her.

Local APRS

When looking at APRS in the Loughton area there is not always much activity. The map below shows the activity with in a mile of my home QTH.


As we look at the map it shows other amateurs around me and some of these are mobile devices or a radio device. A few run UIview32 which allows the upload of data to the APRS network. There are a few fellow amateurs running APRS near by and they will decode the APRS packets. I am working on a APRS decoder to help improve coverage in the local area for which the forest can cause problems with the signal.

APRS

From when I got my licence I decided to learn more about amateur radio than just talking over it. For me I now I hold my 2E0EMO call sign I have started to work on other projects. One of the projects is working with APRS. I started to run the ARPS system via my mobile using APRSDroid. This works well as it runs in the background of my mobile. The software is for Android which on a Samsung Galaxy S3 runs very well without issues.