The Linksys WRT54GS WLAN-Router is a powerful cheap device useable for hamradio. It is about 75,- €, but you have to care which subversion you buy. Please check http://openwrt.org and http://www.seattlewireless.net/index.cgi/LinksysWRT54GS for further details about flash memory and capabilities to use OpenWRT.

Arsene, LX1TB has modified the Linksys WRT54G(S) models to tune the frequencies below 2400 MHz for better fit with the hamradio bandplans Look on his german website to get the details: http://www.rlx.lu/~lx1tb/wrt54gs/.

The WLAN-Router has a MIPS 200 MHz CPU, 32 MB RAM, 8 MB Flash, WLAN 802.11b, a 5-port switch and 2 serial ports which have to be upgraded by hand (without hardware handshake). See http://www.rwhitby.net/wrt54gs/serial.html for the serial modification. The ports support up to 460k8 serial transfer rate !!

The WRT54GS for hamradio usage has been presented at the 21th international packet radio meeting in Darmstadt, Germany. There's a German summary available: Packet Radio Tagung 2005 (nice pics if you can't read German ;).

Some useful hints for hamradio operators:

• The serial modification is just a MAX3232 (3.3Volt) and five 0.1 µF tantal capacitor (if you need serial speed >115k2 DD4RD suggests to use a MAX3380 which can be obtained at http://www.segor.de for example).
• On my WRT54GS /dev/tts/0's default IRQ is 3. /dev/tts/1 is set to IRQ 0. To set /dev/tts/1 to IRQ 3 use setserial. Add “src florian http://openwrt.alphacore.net” to ipkg.conf and install setserial with “ipkg update”, “ipkg install setserial”. Run Setserial: ”/bin/setserial /dev/tts/1 irq 3”. Now you can use /dev/tts/0 AND /dev/tts/1 for any serial device at the same time.
• To initialize a Kenwood TH-D7 for KISS-Usage I have a ugly workaround. First Start Digi_Ned with “digi_ned -p /dev/tts/0:9600:1”. After startup cancel operation with CTRL+C. The serial ports keeps initialized with 9k6. Now send the TNC-commands for switching to KISS: echo -e “\015softdcd on\015kiss on\015restart” >/dev/tts/0. The TH-D7 will indicate changing to KISS by blinking STA CON on the display.
• The wireless bridge will NOT work in ad-hoc or clientmode ! You have to use WDS and AP-Mode for bridging !!
• Get “wl” for using one antenna for TX (wl txant 1) and the other for RX (wl antdiv 0). 0 = antenna @dc-plug, 1 = antenna @reset-switch. Add “src ab0oo http://www.wildcatwireless.net/wrt54g” for getting an archive with “wl” (ab0oo is also a hamradio operator ;)
• You can adjust TX-Power with “wl txpwr 0-255” up to about 160mW. “wl txpwr 100” and above will cause some by-products. Be careful not to overheat the device. Here's a little table (round about):

Adding an SD card reader to the WRT54G: http://kiel.kool.dk/

73 de DG8NGN, DL5RB & DL9SAU