APRS, 868 MHz, inband, SK3W and more

Sorry for the poor update rate, It’s been a lot of people around a lot this summer and I don’t really get the time to sit down and do these things. I spent a few days to build a wooden deck which we also bought new furniture for, it turned out really great!

After I had been down to SK3W a couple of guys from SK3W (SM3XIK & SM3SGP) came up to help me out a bit. We had plans to put an APRS I-gate up in the 60m tower and also the 868 MHz repater (XBEE) that will be used to control the inband tower site and also such things as RX 4-SQ etc that is located far away. It went well and one funny thing was that we lost power from a lightning storm and was just about to put a raspberry pie in the oven. After a while when the power hadn’t come back SM3SGP reminded me that I have an single phase oven in the barn that had never been used and was donated by SM3WMU a few years ago, when I had plans to rebuild the kitchen. So we went out and cut an extension cord which we hooked up to the oven and voila a while after we had our pie :) The power came back again after a few hours.

The project went well but I do suspect that the 5 GHz Ubiquiti links causes some QRM on the APRS frequency because it feels like the I-gate does not hear as well as it should. The 868 MHz repeater works great with really good coverage several km away.

SM3SGP took down the small WARC beam which I lated put in vertical position and improved the tuning a bit so that SM2OKD who will use the beam in the future does not need to do that. I also had some resonance at some winds in the reflector that I hopefully fixed. I think SM3SGP thought it was very nice not needing to do any more climbing, getting to be the ground crew for once.

I also attached a modified 3×1 switch to the 15m tower to switch between the big 15m stack and the new WARC duoband yagi. Some work was also done on the cabinet which will be placed at the inband tower site.

SK3W trip

This year the planned SK3W trip involved trying to remove the top two yagis at SK3W in their 60m tower. These are the two yagis that are hardest to work on since the room to lower them is limited. What we ended up doing was to attach the tram wire from the top of the 60m tower onto the Ericsson tower at 16m height. With a winch on the tram wire we could easily tighten it and with the capstan as lifting power this worked great. SM3SGP did all the climbing and I ended up being ground crew giving orders which was also nice :)

We simulated the 40m stack while being there and ended up with a design that had 28 ohm feed impedance. The 20m antenna design had already been simulated earlier with a close to 16m long boom. When Gunnar and crew earlier had lowered the lowest 20m yagi they found some cracks in the boom which showed it was time to do a renovation of these antennas for sure.

I also met a bunch of nice hams, SM5EPO, SM3SGP, SM3XIK, SM5IMO, SM6MCW, SM5AJV, SM5OXV, SM0W, SM6U and SM0UKE.

Various summer work, part 1

I’ve been busy at the station and I have gotten quite a bit help which has meant that I have felt too busy to do updates on the website. Now I am having a bit more quiet time so I thought I would do some updates.

Quite a bit has been done, the WIFI link has been fixed and has gotten added lightning protection. The tent that flipped over in a spring storm has been flipped to the right side again by SM2XJP and preperations have been done to build a wooden sun deck. Some carpentry has also been done for work and I have been building some roof over the cable conduit etc.

Some more descriptions on the pictures…

Inband antennas are up

A lot has happened lately. I’ve gotten great help from SM2UVU, SM2LIY and SM2XJP which has resulted in us getting the inband antennas up. It was a bit tricky because we had to lift the whole tower 50mm to get the worm gear under the tower since I hadn’t measured that it actually would fit. I thought it should be obvious it would fit but apparently it was not, poor design.

We also managed to get the 2el 40m assembled and hoisted plus when SM2LIY arrived we also hoisted the homebrew OB16-3 antenna. I spent a whole week down at SJ2W and also made a trip down to Kurt, SE2T where I helped him replace the gamma and coax on his 20m yagi. It was a bit tricky since I could not reach the gamma so I had to shift the whole beam so I could reach it.

I have also managed to get the internet link working again and now also with lightning protection at the top of the tower plus the bottom. I have also added extra shielding which should improve their immunity against interference from the HF bands.

A cabinet was also built for the inband tower to hold all control electronics and batteries.

SM3LIC, SM3UZS and my dad visisted as well which was a blast!

Check the captions of the pictures for more information.