Wednesday, 25 March 2015

#cqwpx CQ WPX SSB 2015 wishlist

The CQ WPX SSB, the opportunity to work rare DX, lots of DX. With the help of the excellent "Announced DX operations" list from NG3K  I composed a list of DX that I would like to work as they all are ATNOs for me. It looks like I have more time to spend as last year and hopefully I will be able to work some of these rare DX stations.

5J0B San Andres Isl.
JD1BOW Ogasawara
V6Z Micronesia
KH8B American Samoa
PJ7PL Sint Maarten

Hopefully another DXpedition will take part or can be worked somewhere (WARC).

C21EU Nauru

Monday, 23 March 2015

Solar Eclipse WPA from PA1B

WPA (WSPR Propagation Analysis). Bert PA1B would not be Bert if he wouldn't take the opportunity to take my WSPR results from the database and enter it in his WPA spreadsheet. Wow, thanks Bert, a great tool. This is a really nice spreadsheet with a lot of filtering options. I filtered out the time that the eclipse was on and also filtered all station spots from 100mW and below. This shows something else as just counting spots. Between 9-10 UTC the moment of max. eclipse you can clearly view most "low as possible power" spots. GJ4CBQ from Jersey C.I. would have seen me if I used 100mW only at the maximum of the solar eclipse. Amazing at "daylight" and normally not possible on 160m without a little help from our moon I think! Thanks for the information Bert and a nice addition to the solar eclipse WSPR experiment on this blog.

Sunday, 22 March 2015

Tweaking the HB9CV

Anneli disassembling old gamma rods
It was a beautiful day today, sun shining, birds singing. Though a little cold (6C) we decided to setup my daughters trampoline again. It went well with her help and so there was time left to play.....and tweaking my 10m HB9CV. With a little help of course...

The plan was to change the gammarods. The problem with 6mm2 wire is that it is not able to hold birds and so the antenna got detuned. Although the SWR was good enough and tunable with the antennatuner I was not really happy with it.

Anneli checking...
So I bought some 2m long 10mm diameter alu for the gammarods. I decided to use the complete length and fiddled a slider to connect it to the radiators. As the impedance was too low at the resonance frequency (R=37 X=8) I chose a point 10cm further at the radiator as resonance will be rising then. I was right, I got R=49 and X=1 excellent. But it was on 27.500 MHz. I shortened the radiators by cutting them all 5cm off the tips. Now the SWR is great were I want it. Bandwidth is better. R=45 X=5 is better as well but still not perfect.

HB9CV with new gammarods
Great results for a good hour tinkering. Of course a good SWR is relative. How is the antenna working? I heard a station from Brazil talking with a reasonable constant signal S7. Turned the antenna 180 degrees and he was S0-1, turned it back to Brazil and he was S7 again. So, front/back/side ratio is good. Of course I can't see the gain but I expect it at least 4dBd. Made some quick QSOs with PY2SBY, CE1OEB, PY2VI with reasonable reports. And without the help of the antennatuner now! Although propagation is not that good on 10m lately I'm ready to use it in the CQWW WPX contest next weekend.

SWR curve: yellow old situation - red new situation

When the antenna was back in the air, the tools returned in the garage and the test QSOs made it was time for a delicious diner made by my XYL. I'm a lucky guy....