One month ago, we went for a roadtrip to Vassfjellet in order to install LA2SIX, our brand new radio beacon. Unfortunately, the mountain was not ready for us quite yet, and we were defeated by a large pile of snow in the middle of the road. LA2SIX had to be left behind while we made for the summit on foot. There, we discovered that one of our existing radio beacons, LA2VHF/4, had lost its antenna sometime during the winter and that the antenna wreckage was unusable.

Luckily, we have very good friends at Comrod who have been able to assist us. LA1BEA, veteran ARK slugger, happens to be the technical chief at Comrod, and he was able to supply us with a replacement antenna. Armed with the antenna and new hope, we could finally set out for Vassfjellet one more time last Friday.

The beacon rack is getting crowded.
Photo: LA1WUA

Our ambitions had increased beyond comprehension during the one month’s worth of waiting time: Not only did we want to fix LA2VHF/4 and set up LA2SIX, we also wanted to finally set up LA2SHF again, which has been down since October, and to reinstall our internet link between Vassfjellet and Samfundet, which has been down for such a long time that it has almost not been mentioned at all during the existence of this blog. Would we succeed with everything? Almost! We managed to get three out of four.

LB0VG and LA2QUA installing the replacement antenna base.
Photo: LA1WUA

With the new antenna in place, we eagerly connected the 6 m and 4 m beacons. LA2VHF/4 worked without issue, but LA2SIX only managed to send a series of “dit-dit-dit-dit-dit”. This indicates that the firmware is acting up, and that deployment will have to wait a bit longer until we can fix the issue.

The next thing on the agenda was to restore operation to LA2SHF. This beacon had developed a nasty sideband, caused by injection of the LA2VHF/4 beacon into the 10 MHz reference. A local radio user was impacted negatively by this interference, so the beacon has been out of service since October.

In the meantime, we have been able to work around the issue and reduce the nasty sideband. We also decided to steer the null of our antenna in such a way that the local user is impacted as little as possible by the radiation from our beacon. We’ll give the full details of the sideband issue and the fix in a future blog post, but for now we are happy to announce that LA2SHF is up and running again.

LA3WUA controlling that the antenna null is positioned towards the local user.
Photo: LA1WUA

The final thing that we did this weekend was to restore functionality to the 5.8 GHz WiFi-link that provides data transfer capability to our beacon site. Now we will soon be able to have services like ADS-B up and running again.
The WiFi link, though having been down for the last couple of years, is a nice piece of engineering which we plan to describe in a future blog post.

LB0VG installing new coax for the WiFi link. Photo: LA1WUA

A big thanks to LA1BEA for helping us out with the new antenna. LA2SIX will hopefully be fully serviced this week, when it is up and running we will come back with an update. Getting three out of four fixed is much better than our usual Vassfjellet score, so we are very satisfied with this.

More photos from the trip may be found at
http://bilder.la1k.no/vjf-juni-2019/.