SJ2W Contest Station

I got to the radio QTH on Thursday after me and SM2XJP went to CUE DEE to pick up some aluminum that we ordered earlier. After that we went to buy another 600×2400mm shelf for the radio shack to add so we can put stuff over the monitors. I also bought a 12mm thick OSB board (kind of like plywood) which is meant to be used on the wall of the switch room, so I can add all boxes onto it.

I also cleaned out the barn and made some holders for aluminum tubing which has been lying on the barn floor, a place I don’t like since it’s in the way and can be damaged. I was planning on doing a different solution but unfortunately the room of the barn was exactly 6m, so I needed some more space to fit the tubing. I think the result is pretty good, even though it doesn’t look as perfect as I was hoping for, but it was kind of tricky putting it up by myself.

The 160m vertical went QRT on Monday during a storm. We saw during a storm in the autumn that the three direction guy wire system of the top tube wasn’t sufficient, since such long lines when you can’t tension them properly, is useless and this failure was kind of expected. I had plans to take the top tube down and add another guy line, however snow came and tower climbing season was gone. I was hoping that it would survive until the summer but it didn’t. So now plan is to add one or two more tower sections, making the top tube section very short and if we add two more sections guy line won’t even be needed. The plan to add one or more sections had already been made since we wish to add an array around the vert in the future, however since those tower sections are still in SM3 we couldn’t do it last year. So this will be a project to have done sometime during the summer.

As soon as I get the TS-850 sold (hopefully in the end of March) I will order all material needed for the summers antenna building projects, so stay tuned for lots of updates.

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Posted under Uncategorized

SM3WMU did operate 20m from SJ2W in the ARRL DX SSB Contest. This was his first visit to the station and he seemed to enjoy it a lot. Unfortunately Tomas had to leave early because of family commitments which limited his operating time to only 18 hours. SM3JLA also joined to do some work with me, mainly trying to fix an amplifier which unfortunately did not succeed. It’s an granger auto-tune amplifier which we don’t have any manual for and don’t seem to find one either So right now we are limited using a 4-1000A amp which we need to run down to the basement to tune, so all band efforts are out of the question. Hopefully we will have the amplifier situation solved soon.

ARRL DX Contest, SSB

Call: SJ2W
Operator(s): SM3WMU
Station: SJ2W

Class: SOSB/20 HP
QTH: Da Traesk
Operating Time (hrs): 18

Summary:
Band QSOs Mults
——————-
160:
80:
40:
20: 1052 62
15:
10:
——————-
Total: 1052 62 Total Score = 195,486

Club: Worldwide Young Contesters

Comments:

Guest operator SM3WMU did his first visit to the QTH which was bought 1.5 years
ago. He has been contributing with a lot of gear though so it was a very
welcome visit. However family commitments forced him to leave on Sunday morning
just as the bands started to open.

6el mono @55m
4-1000A amp
FT1000D

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Posted under Contests

I’ve done some more work on the electronics at the station. Now I am trying to finish up the driver modules which will control the antenna switch system. These cards will sit in a room in the basement of the house connected to 2 pcs of 60 leaded cables which leads into the barn in a separate room which will contain all antenna switches.

There are a total of 80 source outputs and 40 sink outputs which are controlled over the homemade openASC bus which works very much like the old coax Ethernet bus.

I will try to finish up this during the week so I can maybe install this within a few weeks at the station. I will also try to finish up the antenna switch boxes so that system is installed before the snow goes away, because then it’s time for antenna work.

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Posted under Electronics, openASC

I had the urge to test to build a QRO low pass filter yesterday, which will probably be needed when we get the 40m yagis mounted in the 60m tower, since they will be rather close to the 20m beams. There are the expensive BPF filters from 4O3A but I figured that for TX filtering a simple LP filter should be just as good and by combining that with the regular BPF between the radios and amp that should be sufficient.

I did some simulations in a software called Elsie where I after I got pleased with a design I simulated the currents through and voltage over the capacitors and noticed that regular doorknob caps should be sufficient for QRO use. The simulations were done in OrCad with PSpice.

The filter is a 7-pole Chebyshev filter which has got 0.2dB passband ripple. However I did place the -3dB filter breaking point to close to 40m so I will need to readjust the values of everything and move it up a bit in frequency, to improve the insertion loss on 40m. If I get down to 0.2dB I will be satisfied. However when adjusting the inductors I accidentally broke a doorknob of a value which I of course did not have more of. So I have ebayed after some extra caps for more testing.

Here are some pictures

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Posted under Electronics