2013-03-09 Searching for source of interference and PLC network
In the search for the source of the interference
I do note the Devolo dlan powerline network has lousy performance when I compare the speed the devolo utilities say I will get compared to what iperf says:Update: it helps when I remember the setup of the system: I installed the wondershaper on that system which throttles bandwidth at .. 1 megabit. Re-running the test with the throttle disabled gives totally different results:koos@metcalfe:~$ dlanlist eth0 Type MAC address Mbps TX/RX Version/Product local 00:0B:3B:5F:95:AB ---.-- / ---.-- INT6000-MAC-3-3-3348-00-2764-20080808-FINAL-B devolo dLAN 200 AVplus [MT2165] remote 00:0B:3B:6F:AE:90 73.50 / 112.88 INT6000-MAC-3-3-3348-00-2764-20080808-FINAL-BAnd from iperf:[ 3] 0.0-10.2 sec 1.43 MBytes 1.18 Mbits/secInteresting difference of opinion there, 73/112 megabit versus 1.18 megabit.[ 3] 0.0-120.1 sec 308 MBytes 21.5 Mbits/secTesting with udp gives even higher speeds:[ 3] 0.0-120.0 sec 1.34 GBytes 95.6 Mbits/secAnd in the other direction:[ 3] 0.0-120.3 sec 649 MBytes 45.2 Mbits/sec 0.204 ms 1075187/1538185 (70%)Reception of 2 meter radio doesn't get worse/better during these tests. According to the devolo dlan 200 faq the devices work in the range of 0 to 30 MHz with notches for HF amateur frequencies. With the software defined radio I also see no change in the 2 meter band when running bandwidth tests. Which doesn't say a lot: I can't even find the output from PI3UTR at 145.625 MHz in the output plot, even with a receiver nearby receiving that same signal fine. The output plot does show APRS active on 144.800 MHz.