Antenna switch progress

This weekend they promised rain at SJ2W so I decided to stay in Luleå instead. Spend some more time with my girlfriend but also get some work done on the electronics. Earlier this week HA1AG guided me a bit through dissembling the FT1000MP MKV which had stopped delivering any output power. After checking the voltages etc to the finals which looked OK I started going backwards to see where the RF signal disappear and it did just before the finals. So I started measuring the bias voltage of the amp stage and it showed that the inductor in series with the bias was burned. So after changing it the radio worked again and HA1AG guided me through some of the tuning process along with the tech reference of the MP. Thanks to Zoli that helped me an convinced me to try to fix it myself before sending it to him. So instead of paying a lot in shipping it ended up costing me about 5 euro including of the inductor shipping.

Today I built another powersplitter, this one is intended to be used on 10m now when we hopefully soon get the 10m yagi up in the 60m tower. This time I put a fan on the device since we noticed that the 20m unit got quite warm in the WPX CW contest. So now when there is no radio activity I will plug the air holes and have the 15w heater inside each box to keep away moisture and during the contests we remove that and start the fans. So I will need to modify all the boxes which are currently at SJ2W as well. I also built a 6×2 switch which will make it possible for us to route four radios to any of the antennas, up to 18 different antenna systems (3 on each band). I have however run out of 7/16″ connectors so until I get hold of some more the switching system can’t be completed. This is because each band need to have a powersplitter even if we just have one antenna on the band. This is because of the A/B output on the splitbox, making it possible to route the powersplitter to either 6×2 #1 or 6×2 #2.

I am not very pleased with how the 6×2 turned out. The mounting plate for the connectors/board is fine but the casing wasn’t very nice. I couldn’t fit it in the milling machine so I had to bend it by hand which is always a mess, at least when not taking it slow and careful. I don’t like to spend too much time on making these things look perfect, I try to make the visible things in the shack look perfect, this kind of things is fine just as long as they work.

Leave a Comment


NOTE - You can use these HTML tags and attributes:
<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>