SJ2W Contest Station

Filtering of the station finally decided

Posted by sm2wmv on November 16, 2012 1 comment

I have finally decided how to do all filtering at the station. Right now it works quite OK, we don’t suffer from too much problems but I believe it should be possible to totally get rid of all harmonic problems etc. When I connected the 80m notch filter I built I noticed no change, which made me convinced that the current problems are in the switching system. So I decided that the filters used to suppress harmonics will need to be placed directly after the amplifier before the antenna switching. So I decided to build a pair of 1×4 switches used to connect the harmonic suppressing filters for 160,80,40 and 20m. I regret not making it 1×5 though, to have one position which bypasses the filters (15/10m), so I will need to use the 160m position for that until I fix another pair of ports.

The other idea is to make a few RX only notch filters. I will make one set of filters for each band and connect all in series except the filter used for the current frequency will be bypassed. That way I can have huge attenuation on the main signals and when also suppressing the harmonics the station should be very well protected against QRM between the bands.

There are also some pictures of how it looks at my land now when the forest machines have been on it. A lot more room now for the new 60m tower.

Tomorrow I am going down to the station to prepare for the CQWW CW contest. SM2XJP went down to SM3 land to pickup another MKV that I bought so now the setup will be 2xFT1000MP MKV which I am really excited about. SM2LIY is at the QTH trying to get the beverages ready for the contest which I will do as SOAB for the first time since WPX SSB last year. This is the first SOAB CW I do on CW for a long time, so hopefully I am not a total lid.

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Filter design

Posted by sm2wmv on November 5, 2012 Comments Off

I was trying this weekend to build a Cauer LP filter that I designed for 80m with notch at 7.1 MHz. I did not get the performance of the filter as I wanted and they are quite hard to tune with those big pipes etc to bend. So instead I decided to go for a design very similar to the one ON4UN describe in his book with notches instead. Those are easy to adjust since you see very well what you are doing and also they do not have a big impact on the other notches. Another advantage is that you can get very low insertion loss and for this filter I was aiming for better than 0.1dB. I decided to skip the notch for 160m but I might add a notch small enough so that It does not impact the insertion loss and give maybe 20dB of depth. I also need to add the rest of the box and fine tune the notches so that they are behaving as they should.

The idea is that I will build these filters for the radio 1 and radio 2 position in the switching system. On 160/80m where we just have one antenna it will sit directly at the antenna and be used on all four radios. The notches both remove the harmonics generated by the amplifier but will also remove other transmitting radios main tone. I will build another filter for 40 and probably also rebuild the 20m LP-filter I built earlier as well to a notch filter.

I got VERY happy with the result, maybe I would have wished the 40m notch would be slightly deeper and could probably be possible by fine tuning the series inductor but I would need to make another one, so I think I will just stick with the current design.

Attenuation on 3.755 MHz is 0.05dB which is a lot better than the 0.1dB that I had as goal.
40m -> -56dB
20m -> -53dB
15m -> -66dB
10m -> -72dB

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Harvester making room for the 60m tower

Posted by sm2wmv on October 31, 2012 Comments Off

Except working the CQWW DX SSB contest I marked out the spot where the new 60m tower will be placed. The plan was to make quite wide room for the guy wires so that no trees would be able to fall over them. But when we started marking out the paths supposed to be cut we realized that not much would be left, so instead we just took all of it around the footprint of the 60m tower. That also makes us get a big room where we can lift towers from. If we would have done this by hand I think we would have been working for a LONG time, now this machine does it 2-3 days and I might even have some money leftover after the trees have been sold to the forest company. It hurts a bit though to do this, but i think it will look nice when the tower is in place and all branches has been removed.

I got to ride with him in the harvester too which was really cool, what a piece of machinery! Just amazing how efficient it is even though this is a quite small one it does a great job! I think I spent a couple of hours with him in that machine.

SM2NOG also came over with the 40m military tower with help from his brother. So now that tower is also in place. I saw some welding need to be done on a minor broken part of it but otherwise it looks great and ready to be put up. So now we just need to wait for the spring so we can continue this project.

And Zoli, I’m sorry but the trees had to go 🙁

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CQWW DX SSB 2012

Posted by sm2wmv on October 30, 2012 Comments Off

This year as usual we attended in the M/S class. Our hopes to beat last years result were not really high even though propagation’s were awesome the week before the contest. However the SFI dropped by the start of the contest but we did not suffer from any aurora which was a real upside. I had set a goal that if we made over 6000 qsos I would be happy and we did do that with quite a margin. The start of the contest was the most amazing I have ever experienced. We worked 491q first 2 hours, 705q in the first three hours were most were 3 pt QSOs on 20m. After 12 hours we had 2396 contacts and at the 24h mark we were at just under 4000 QSOs. The second day was not as good but we could end the contest with several 100+ hours of 3 pt QSOs towards NA on 20m which is always a relief not needing to work EU on the lowbands.

                    CQ Worldwide DX Contest, SSB

Call: SJ2W
Operator(s): SE2T SM2LIY SM2WMV SM3JLA
Station: SJ2W

Class: M/S HP
QTH: Da Traesk
Operating Time (hrs): 48

Summary:
 Band  QSOs  Zones  Countries
------------------------------
  160:  187    10       55
   80:  201    23       90
   40: 1129    34      125
   20: 2124    36      138
   15: 1644    34      133
   10: 1358    40      145
------------------------------
Total: 6643   177      686  Total Score = 11,726,444

Club: Worldwide Young Contesters

Comments:

Not as good propagation's as last year so we could not reach last years result.
We can not complain though since we pretty much had no aurora at all during the
whole weekend. The only sad part was that the SFI dropped just before the
contest which made us lose some of the night propagations on 15/10m but 20m was
absolutely amazing during the first night. We did more running on 10/15 this
year which also explains the drop in our 20m numbers compared to last year. It
was nice to end the contest with several good hours of US runs on 20m as a
result. Hats of to the other EU teams that keep competing in the this category
which must be the toughest one in this contest.

We had fun but we are lacking operators as usual, it seems like contesting in
SM2 is not very popular, which is a bit sad.

Everything worked great and we used N1MM instead of Win-Test,and it worked
great  during the whole contest and will be used in the CW part as well. We had
three stations running but still no inband option, hopefully its completed for
the CW-part. We lack good flexibility on 20m which I hope to improve for the CW
part with a 5el mono that is rotatable for 20m.

FT1000MKV + 4-1000A
FT2000 + ACOM 2000A (from Ojojoj Music AB)
IC-7400 + 4CX1500B

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