I wrote my first post here exactly 2 years ago. This morning the hit counter showed 5022 individual hits, somewhat surprisingly high figure. I hope this is due to usefulness of topics rather than misleading keywords.
Some time ago I bought a cheap DVB-T USB dongle from ebay. I was inspired by several stories found on the internet how to use it as a primitive SDR (software-defined radio). Somehow I didn’t get around to do anything with it, partly because most of the instruction in net were for windows based PC’s and those I found at that time for linux were command line programs.
Recently I found a package called gqrx. It combines gnuradio and osmocom files into a nice package that resembles sdr# (sdrsharp). I decided to give it a try.
And now for something completely different…
Last Summer I took my vanity call (OH2HA) into use and decided to try how long it would take to work 200 countries again starting from zero. First time it took 35 years with my other call (OH2BSC).
The goal was achieved on April 8th 2014, in 9 months. All qso’s were made on 100W, most of them with my trusty 15+ year old FT-1000MP. The main contributors were better antenna (6 element log periodic Tennadyne T6) and more extensive use of CW (1/3 of countries were on CW). Maybe I even have learned something about working DX. Solar cycle 24 certainly helped, but I’ve seen better sunspot numbers in the past. Still I think the most important contributor was, that during the last 5 years my hamshack has been computerized.
My friend Ari OH2BSF built his version using Raspberry Pi instead of a laptop. Othervise the setup is the same than described in the previous posts, soundmodem as TNC and xastir as APRS client.
Hugo XE1BEP has built a similar system, and he has also written an excellent document how to turn a Raspberry Pi into an iGate using xastir and soundmodem. His version includes the instructions how to connect a serial GPS into the system. Here is the link to his document:
https://docs.google.com/document/d/1OG57JrSqYu83ZzzMiOwrWMEvXSWK2LH62yPjb8OX6oM/edit?usp=sharing
It’s been a while since the last update. Let’s wrap this topic up by going through the final set-up for the minimum hardware (= soundmodem based) iGate.
Part 1 lists all the needed building blocks for the iGate. PC, linux/ubuntu operating system, soundmodem software, xastir software (aprs client), internet connection, 2m FM radio (only RX is needed for iGate) and an audio (stereo) cable with 3,5 stereo plugs are needed.
Part 2 shows how to configure the xastir for the connection to APRS-IS server. In this case there is no GPS, but your station location is entered as part of the station configuration. This makes sense for a fixed station, especially for an iGate.
Part 3 shows how to configure the soundmodem. When this is done it might be a good idea to test that the soundmodem works properly. This can be done with the soundmodemconfig’s Diagnostics functionality.
One way of building iGate is to connect a TNC between the receiver and PC. Since I wanted to set up a minimum hardware iGate and since I didn’t have a suitable TNC, I use a SW called soundmodem between the radio and PC’s soundcard.
Xastir is a versatile APRS client which I have configured to send my location to APRS-IS server network. Xastir is in Ubuntu repository so it’s easy to install either by using synaptic or by typing “sudo apt-get install xastir” on terminal.
I’ve had an Xastir APRS client running on my shack’s computer for years. There’s no GPS, so it shows fixed location. There’s no radio either, information flows both ways via APRS-IS server.
My IC-R5 receiver was sitting idle, so I started to wonder how to turn it and Xastir into a minimum hardware iGate. In Greater Helsinki area there’s no need to improve APRS coverage, but when has the real need been the driver in this hobby?
The minimum setup for an iGate requires:
The only tricky part is the soundmodem configuration. Instructions found on the net didn’t work with Ubuntu 12.04. In the next post I’ll show how I configured mine.
It looks like my Fritzel FD4 windom antenna has an undocumented band. SWR (blue line) is well below 2:1 throughout the 6 m band.
I also tried it on 4 meters but SWR doesn’t look promising.
Ubuntu releases 2 new versions every year, in April and October. About one and an half year ago I got fed up and decided to update only when a long term support version is released. In synaptic you can choose to get notifications only for LTS versions. Here’s the Ubuntu release timeline.