It all started in 2007 when we started think about making some things easier during the contests. One of the first ones that came to mind was automatic antenna switching. Having had Yaesu radios all the time at OH5Z made designing the antenna switching system a bit easier with the BCD data out from the back of the FT-1000MP. The main principal at the time was to be able to share automatically as many antennas as possible between four operating positions we had at the time. I searched the internet for commercial solutions but either they weren’t suitable or they were out of the budget. I decided to build the system by myself. I contacted Mike SM2WMV (SJ2W) with my ideas and he made a dozen PCB’s for us. After ordering a lot of relays, boxes, connectors and a lot of other stuff I started building the system.
The original antenna switching system consisted of 6pcs 2×1’s, 2pcs 6×2’s and one 6×1. I also built a pair of stack matches. We can share all the antennas from 40-160m between all the stations with lockout system. On 10-20m bands we can’t share the big stack of four tribanders anywhere else than to RUN1 position. We have this limitation as they are all fed with one feedline and we are not using triplexer with them. All the other 10-20m antennas were originally shared between the three multiplier stations. Before CQ WPX 2014 SSB we added four more boxes, 3pcs 2×1 and 6×1 which now allows us to have three directions on RUN1 position on 10-40m bands.
During all of these years we have worked almost 90000 QSO’s and we have lost maybe 2-3 relays in total. That proves that Mike’s PCB designs are working great. We have had some RFI problems with relays clacking when shouldn’t have but the reason has been quite often on poor RFI protection on the band decoder end or some cable acting as antenna near the boxes.
73, Juha OH6XX