The remote station is located on the Colorado plains about 35 miles east of Denver. It is controlled over the Internet and is exclusively solar powered. Begun in 2016, it now has a variety of antennas and equipment. In this picture, from the left, is a 60 foot tower with a Hygain 203BA 20 meter yagi. The tower is also used as the driven element for a 160 meter vertical yagi. Next is the equipment shed which has the Internet dish on the roof and a dipole for 12 meters on the right end. Next is the vertical which is the director for the 160 meter yagi. To the right of it is a DX Engineering 43 foot vertical which has a MFJ 998RT tuner at it’s base. Next is a 30 foot tower with a Cushcraft A3S triband beam for 17, 15, and 10 meters. The yagi on top is a Cushcraft 505S 5-element 6 meter beam. Both towers tilt over for maintenance and additions. The dark-red posts are gyn poles to help lower the towers.
Inside, above my head is a Victron 3000 watt 24 volt to 230 volt inverter for the linear amplifier. Two Yeasu rotor controllers make the yagi’s turn. On the counter are the linear amplifier and a Flexradio transceiver. On the right hand side are all the solar controllers and Internet equipment. The LifePO4 batteries are on the floor.
The maximum transmission unit (MTU) is the largest size frame or packet — in bytes or octets (eight-bit bytes) — that can be transmitted across a data link. It is most used in reference to packet size on an Ethernet network using the Internet Protocol (IP). A deprecated term is “window size”. Default is 1500 which is too big for the remote station network. Symptoms are, the radio shows up in the Smartlink window but a connection attempt times out.
At least two workarounds are possible which will have no effect on any other applications or users on the router. The first one is to change the settings in the main router for the home. Find the settings for MTU in the network configuration and change the MTU to 1438.
The second workaround uses the command line to do network shell routines. This routine can change the MTU on the PC. Open cmd with administrator permissions and enter these commands.
>show int Look for the line that shows the connection to the Internet and write down it’s name. An example is “Ethernet”. Observe the value in the MTU column. Is it 1500?
Enter the following command.
>set subinterface “Ethernet” mtu=1438 store=persistent where “Ethernet” is the name obtained in the previous name.
An “ok” will be returned if these steps worked. To test, enter the following command:
>netsh int ip show int
The results returned will show the current MTU.
Note that the magic number may be lower or higher. Experiment, if the one above doesn’t work.