And even more filters…

People might think I am crazy building all these filters all the time. But I think it’s really fun and I learn a lot by doing it. Now I think as I wrote in the previous post figured out how to do the filtering at the station. These RX filters will sit in the RX-path of the transceivers and I might do so that they are switched in depending on which bands the other radios are on. For example if the run station is on 20m then the 20m filter will be switched in on the mult stations and if one mult station is on 15m then that filter is switched in on the other mult plus also the run station. That way I will have the least amount of insertion loss possible, since it’s no need to use filters on bands which does not have any radio transmitting on them. Not that the insertion loss is high, but every 10th of a dB counts, at least in my opinion.

I first tried to build the filter on a PCB that I milled but it was extremely hard to tune it and I could only blame it on coupling between the filter nodes and I did not get near the performance that I expected from simulations. The filters are 5-pole chebyshev notch filters. So to test my theory I built a box with chambers and added pole for pole into it and measured and already with three poles I beat the old result and a lot better insertion loss as well. When adding two more poles the result was close to the simulations and I am very pleased with the performance.

Now I need to figure out if I should be pleased with just three poles or if I should go for 5 poles, we will see. I think I will make a bunch of filters in a big box and make chambers for it, will be a lot of work but I think it will be a great result and totally worth it. But I will make another test first, and that is to use toroids on all five inductors and that way maybe the coupling will be so low that I don’t need to use chambers, it’s worth a try because it would make it A LOT easier to build them.

I also put a Webswitch which we got sponsored from Microbit 2.0 AB into a box, that will be used at the station to be able to switch gear on and off over ethernet. That way I can reboot stuff if needed and not needing to have power on to the openASC system the whole time etc.

CQWW CW 2012

Yay, a new record which I am very proud of. Felt I could not have done it much better operator-wise considering it was my first SOAB in CW for many, many years.

For more stats, check the 3830 post

                    CQ Worldwide DX Contest, CW

Call: SJ2W
Operator(s): SM2WMV
Station: SJ2W

Class: SOAB HP
QTH: Da Traesk
Operating Time (hrs): 47.5
Radios: SO2R

Summary:
 Band  QSOs  Zones  Countries
------------------------------
  160:  110    10       46
   80:  401    22       71
   40: 1411    31      105
   20: 1978    35       89
   15:  503    32       92
   10:  149    28       83
------------------------------
Total: 4552   158      486  Total Score = 6,353,704

Club: Worldwide Young Contesters

Comments:

This was so extremely fun, what a battle! This year I was planning on doing the
CQWW DX SSB SOAB but some problems with my neck and back made me change those
plans to do M/S instead. After going to the chiropractor a few times I felt I
was good enough to give it a try.

The goal before the contest was to do > 4000q, >140z and >500 dxcc. I failed
the last one but I might excuse that on 15/10m being very bad on Saturday up
here, we barely got any solid openings during the whole weekend. It opened up a
bit due to aurora on Sunday which made me able to snatch a lot of multipliers
that were not heard on Saturday.

I did not expect to have a very good and fun weekend because of the prognosis
of the CME that was heading towards earth, but funny enough it seems like it
gave just the right type of propagations that seemed to have helped me to pull
infront in the nordic battle (ES5TV, OH8X, OH0X and LN8W). It was VERY fun to
see on the realtime scoreboard, it really gives a whole new dimmension to the
sport.

Everything worked great at the station. The ACOM 2000A that we got sponsored
worked extremely well on the 2nd radio, moving mults was so simple and fun.
However most people don't seem to understand what QSY 10m? etc means.

I will need to start working out though because I was in so much pain after the
first 24h (shoulders mainly) that I did not think I would make the 48h. However
I did try to move around a bit more and it got a bit better. I was also very
sleep deprevated on Sunday morning so if I acted like a big LID during that
period, please excuse me. But the two 15 minute naps I took in the contest
worked like a charm. However I think I will need to try having a strategy how
to actually get some sleep BEFORE the contest starts...

SO2R is so much easier on CW than SSB. N1MM said 579 2nd radio QSOs but some of
those were periods when I did some CQ on the 2nd radio, so my guess would have
been around 300-400q. I mainly focused on finding mults and not much else. I
felt that when having decent rate I would gain more on scanning the bands
intensivly than working 1 pointers. However my brain did not like having the
right radio as RUN so I ended up turning the VFO sometimes, so I went back to
just using one radio for CQ and the other for S&P. The ALT+F5 command in N1MM
worked very neatly swapping the radio frequencies. And the late addition of
another MKV in the shack made SO2R even more enjoyable having identical
radios.

I hope more people join this scoreboard stuff at http://cqcontest.ru, very fun
when most of the nordic competitors were posting (ES5TV, OH0X, OH8X, LN8W).

Congrats also to Kim, OH6KZP who got to kick some butt from CR2X!

Check our website, lots of fun stuff can be found there and updated
frequently.
http://www.sj2w.se/contest/

Thanks for the QSOs!

Antennas
160m: 39mh vertical
 80m: 4-SQ
 40m: 3/3el   + 4-SQ
 20m: 6/6/6el + 5el  + 4el @EU
 15m: 6/6el   + 5el
 10m: 6/6el   + 6el @46m

Radios: 2xFT1000MP MKV
Amps:   4CX1500B + ACOM 2000A (Sponsored by Ojojoj Music AB)

Filter switch connected

Today we spent some time to get the rotator up in the WARC tower working. So now it turns the 5el 20m beam but it does it very slowly, it takes three minutes for a whole lap so I will need to run it on 24v. However for the contest I will run it as it is since I don’t have a 24v supply which can supply enough current to rotate it. Anybody have one that they dont need? I also need a new 13.8V supply which can supply 10A or more.

In the evening I hooked up the filter switch i recently built. Its connected after the amplifier and puts in notch filters depending on which band we are on. Currently I have filters for 80,40 and 20m. However the 40m filter need to get some notches added to it to notch away 15 and 10m as well and not just 20m as it does now. I will also need to build a 160m filter that notches away all bands except 160m.

5el for 20m up

Today and yesterday I got some help from SM2XJP and SM2LIY to get the 20m 5el CUE DEE monobander up in the air. The weather was very nice, a bit windy yesterday but otherwise it was very nice with just a few minus degrees. This tower is the WARC tower, which is supposed to hold the 12/17 duobander and also the 6m yagi. But since we did not get the 40m military tower up this year we decided to put the 5el mono in this one, making us a lot more flexible on 20m.

It has got an alfa spid rotor. These kind of towers are horrible to climb when you have a rotor in them, because you can barely get your feet in to stand properly. So its not a fun experience working in them. When me and SM2XJP were putting a connector on the RG-17 inside the house he said to me “Mike, did you remember to put the center connector in the 7/16 connector” and my response was something like “f**king s**t”. Eager to try the antenna that its working as it should I did a climb in total darkness with a headmounted flashlight which was actually quite nice. The SWR looks good over the whole band and tomorrow I will connect the cables for the rotor so I can get it rotating as well.