KC6HUR(-L)

Originally, the KC6HUR IRLP Node 4494 was designed to be a test-bed for developing IRLP scripts and be a micro-node serving the area around my home QTH. The micro-node would also makes a great tool for accessing the JPLARC repeaters via their IRLP Node 3340 (which I also maintain). My home was on the fringe of the repeater and the micro-node would make handheld coverage into the system possible.

Now, thanks to some advances in the Asterisk/app_rpt module, I was able to construct a full-fledged repeater system and interface the IRLP node to that repeater via a direct connection. The IRLP no longer connects to a simplex 440 radio, it is connected to a complete 440 repeater system, with the ability to connect to other Allstar Link nodes (repeaters, remote bases and more).

Please see the KC6HUR Repeater pages for more information about my new setup.

The Hardware

The Computer

The computer is an old Compaq Deskpro 350MHz Pentium II, 192MB RAM, 80GB HD (smaller drives are hard to find :-D). While the Compaq has onboard sound that works with IRLP, it only has MIC In and Line Out; therefore, I added an old Soundblaster 16 card whic fills one of two expansion slots and the IRLP is mounted to a cutout panel, filling the second expansion slot.

The computer has proven quite reliable; however, I have to use a different than the built-in CD-ROM drive to install IRLP, and Linux does not know how to power off the computer when doing a shutdown. It just runs and runs, it is quiet and never gets hot.

The Radio

The first radio used on Node 4494 was a Kenwood TH-F6a HT! While as strange as this might seem, it was an ideal candidate. When the TH-F6a is placed in TNC mode, the COS signal is presented on one of the pins of the external MIC/Speaker connectors. (Thanks to Donn Lee W6FYI for making this discovery). Once I had built the cables up, the interface was a "snap". As it turns out, this radio provides excellent audio. Too bad it does not have a Micor squelch.

APRIL 19, 2003 KC6HUR The TH-F6a may not be as suitable for node use as originally thought. This is due to the fact that the CTCSS setting has no effect on the COS output; therefore, it is possible for signals without the correct CTCSS to cause your node to send dead air to the Internet. The CTCSS does control the muting of the audio so that no extraneous noises will be heard, just a dead "carrier".

The HT was replaced a year later with an Alinco DR-435 MkII. This radio is well suited to the job. It has a DB-9 connector on the rear panel where all the necessary interface signals can found. Best of all, the COS it tempered by the CTCSS. The bad news, PL decoding built into the radio really sucks and can take upto 3 seconds to figure out that the CTCSS on the signal input has gone away. Bleah! I still used it for a few years.

Now, the node is interfaced directly to the KC6HUR Repeater "controller".