SJ2W Contest Station

Pouring some concrete

sm2wmv — Mon, 20 May 2013 20:43:15 +0000

I am spending the week down at the station preparing for WPX CW coming up and also doing some work on the house. I decided to get a concrete floor in the room where I have the openASC driver cards and also the pump for the water in the house. For some reason only half of the floor was concrete and the rest was sand, so I decided to change that. It was a bit tough work though mixing the concrete will the drill and doing it by myself, I had a walk with buckets down and pour it. It did harden quite fast so I had to hurry as well…when I do the big room we need to be more people and also I need to use a real concrete mixer.

Last week I also built a unit which will solve the inband issues I had with PTTing that I will try to install tomorrow so I have plenty of time fixing if something doesn’t work as intended. On Thursday I am going to get a visit from my father together with SM3LIC and SM3UZS which will be fun. LB3HC will arrive on Thursday evening and will be spending a few days at SJ2W and also working WPX CW with us.

I also finished up some minor things on the house, so now two sides are completely done and one side is 95% done, so pretty much just one side left to do, which I hope to have done in June so the rest of the year can be spent on radio stuff.

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Grounding work

sm2wmv — Wed, 15 May 2013 18:59:39 +0000

I spent a few days down at SJ2W. I had a couple of computers I had gotten from work that will fit well into the shack upgrading a couple of the computers a bit. It’s old P4 but the latest models and with 4GB RAM, so they will be useful as logging computers. SM2XJP said he could come up and get them so I got to ride with him down to the QTH and when I got there SM2LIY was already there.

The weather was bad most of the days but I managed to get the inband electronics installed and me and SM2LIY played around a bit trying it out in CQ-M. I decided to try a W7IUV preamp instead of the MMIC I had built but after a little while the W7IUV acted very strange and I suspect I fried it, so we put the MMIC back and it seem to work OK. However we plan to move the vertical to a location which is SE from the main antennas, which should be a direction that we rarely beam much, especially not with the bigger antennas. I noticed a problem though which I have made a little card with a micro-controller that will solve.

I got a lot of stuff attached to the ground system we laid down last year. Now I feel quite confident in the grounding of the shack, and since the coaxes between the barn and shack gets disconnected, only direct path from the antennas to the shack are the control cables. I will add GDTs to these along with the MOVs that are already in place.

Me and SM2XJP also went to SM2RMG and picked up two K-600 tower sections, manufatured by the CUE DEE company which was created by the famous SM2DMU. SM2RMG had gotten them from work and gave them to us for free. One will be used to help making the foundation of the military tower. SM2UVU is working on making a plate that attaches the base bearing to the K-600 tower section.

Keep tuned…

Hopefully I’ll spend most of next week down at the QTH getting more work done.

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Some various pictures

sm2wmv — Sat, 04 May 2013 15:41:27 +0000

I was going to drill holes in the guy wire ring plate that SM2DMU donated to us. But it was very hard to try to measure out where to drill the holes so I will take with me the small 20cm piece of tower I have down at SJ2W and use it to mark out where the holes should be. I was thinking about making a template in paper but it’s so big that it will be tricky, so easiest way is to use the small piece of tower instead.

I have recovered from the flu so I will be going down to SJ2W probably on Wednesday and stay there at least until Sunday, maybe longer. Hopefully I’ll get some work done. We need to go to pick up a couple of K-600 sections from SM2RMG that will be used for the base of the military tower project.

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Got sick

sm2wmv — Mon, 29 Apr 2013 19:49:19 +0000

I had planned to be at SJ2W this whole week but managed to catch a cold and have been lying in bed for a few days. So plans are to spend a bit of next week at SJ2W instead getting some spring work done outside.

For the Swedish people here, I am in hunt for another tower. I need it to be 24-40m high and hopefully strong enough so I can make it rotatable. The backup plan is to build a tower but I would rather get hold of an already made one. Plan is to use it for inband operation in the future (maybe next year?) so I can put a triband stack in it and a 2el for 40m. I’ve been playing around doing some simulations of putting 3xJP-2000 tribanders which would be awesome (3el 20, 3el 15, 4el 15).

A thicker model (thicker than 280mm side) of the WIBE towers used by the military would be an OK backup plan. One could weld cross brases to stiffen the tower up making it possible to make it rotatable.

Various work at the station

sm2wmv — Sun, 21 Apr 2013 19:10:56 +0000

This weekend me and the girlfriend went down to the station with a trailer we borrowed from a friend. I got some 7/8″ cable from SM2OAN earlier (5 pcs of rolls, about 50-70m long) that we took down and also some shelves and other stuff that was going to be thrown away at work. SM2RIX managed to get us a 220m roll of 1 1/4″ coaxial cable last year and I am missing about 220m more to have coax that we can use for the inband tower planned to be put up in the future, some 400-500m away from the other antennas. Hopefully I can manage to find a longer piece of coax for that so we don’t need to have so many possible failure points. However, in worst case that would be OK too. These coaxes will be used for the 40m tower project this summer and might also be enough for the 2nd 60m tower planned next year, for 80 and 15m.

I got the shelf put up in the basement which is good since I have a lot of stuff lying everywhere, so it’s pretty hard to keep things tidy, however every place to store things is a step in the right direction, but since I tend to just get more junk I guess I will never get rid of this problem

I also cut down an old bush that had been beaten by the snow a couple of winters, so now it can grow up and be pretty again. I also did some work preparing to fix the yard since we dug it up last year I will need to fill in with soil so we get grass there again and make it a bit more even. And it was very muddy, if we would have needed to stop on the road to the QTH I believe we would probably have gotten stuck, however its “only” about 1.5km so it’s not too bad. The yard is a mess too, very muddy so we had to park the car out by the road. The snow is melting very fast and there is barely any snow left in the woods, so the inband vertical should be useful for WPX CW so I will need to put the amp project on hold a while and fix the electronics for WPX CW so we can use it.

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Amplifier progress

sm2wmv — Thu, 18 Apr 2013 06:13:28 +0000

I did more work on the amplifier project. I did cut some aluminum sheets and also made some clamps for the inductor in the PI-filter, so that I don’t need to solder it all the time when tuning to the correct Q.

Now its ready for some paint!

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More power supply work

sm2wmv — Sun, 14 Apr 2013 16:36:57 +0000

Today I welded a bit more on the power supply amplifier box. I also grinded down all the welds and removed the paint so now its ready to get pretty with some black colour. I also drilled holes for the screws holding the side panels and got threads into those, it looks pretty good. I need to cut one of the panels since it was too long.

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Welded together the box for the power supply

sm2wmv — Sat, 13 Apr 2013 18:20:18 +0000

Today I spent some time welding together the pieces I cut yesterday to a casing on wheels. I got it pretty much perfectly straight which I am very happy about but it was some work to get there. Now I will need to remove the paint so I can repaint it so it looks pretty. When I have grinded down the welds I will put the sheets on it and drill the holes. I also need to add some support inside for the transformer etc.

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Some pictures from the SK0UX visit

sm2wmv — Sat, 13 Apr 2013 14:05:15 +0000

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Various stuff has happened lately

sm2wmv — Thu, 11 Apr 2013 20:41:44 +0000

SM0W, SA0AZT and SM0SHG came up to spend the weekend at the lab at work building antenna switches and I finished up the openASC-boxes for SK0UX. It was a lot of fun and we got lots of stuff done. They still have quite a bit of work to do but they got with them the openASC boxes as well, so now there are three stations in Sweden using the openASC system, SK0UX, SJ2W and SK3W.

It also seems like I am claimed #1 Europe on 20m SSB in WPX SSB which is a lot of fun!

I also did some tests to test if the theoretic Q-value of the PI-filters we use in amplifiers correspond to measurements done with the VNA. It did not match at all, I got the values 4 times higher when having Q-value of 12 on the VNA compared to the theories. However I need to do more thinking and testing on this to figure out why. Maybe somebody can explain? I used the -3dB bandwidth to calculate the Q-value.

I also spent time cutting metal for the power supply for the amplifier project. I’ve collected some material at work which would have been thrown out and used it for the amp. I also bought some wheels that will be mounted to the amp which limits the weight of it to 400kg, but I should have quite some margin

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