HDSDR trackerball VFO project

I have been working on a trackball based controller for my HDSDR SDR project lately. This is a small R&D project that is run on my spare time where the goal is to determine if it is possible to use a trackball as a VFO for software defined radio (SDR) in contests. The project started out based on a demand for a more ergonomic way to operate a mult receiver in a contest environment that is less fatiguing during 48hours duration of a major contest like CQWW or CQWPX. The goal is that it should be possible to operate all radio functions you need from one hand only: VFO, speed of vfo, band, mode, filter width, volume, gain. I have modified a Marconi trackball and the controller is a Trinket Pro controller (Arduino)

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Contesting from CR3L (Madeira Island) with RRDXA

I am back from the megalocation at CR3L Madeira Island after working CQWW SSB with the R25 RRDXA team. It was a great weekend and we achieved good run rates however our targets were set at a higher QSO number. Since CR3L is in AF zone 33 we worked three pointers both to Europe and US and got a good score. That was fun. Claimed score looks like we will be around number 9 worldwide (a bit above 15M points). The CR3L Madeira station is located at Santana in a mountain side on Madeira overlooking salt water.  Thanks to the team! Ops: DF4UM, DH4JQ, DJ5KW, DJ8VC, DL1EK, LB3HC . Stay tuned for 2013 events.

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Claimed #9 WW score in CQWW 2012 contest from CR3L (Madeira) LB3HC in the foreground and DH4JQ in the background (we are working pileup) DF4UM in the foreground and DJ5KW in the background (working pileup)
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DH4JQ on rig A DL1EK in the foreground and DL8VC in the background (working pileup) N1MM logger
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RIG B Weather changes fast. Here the shack and the lower antenna in fog! The team after the contest
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The 80m vertical The 10m 5 el tower is “adjusted” by DL8VC! The lower Threebander and 160m ant
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Ready for takeoff from Madeira Island Approaching coastline from flight over Atlantic Ocean On the way back to mainland Europe

Contesting @ SJ2W

Edit 15. April 2015: since last time I also operated Russian DX contest from SJ2W. Good results. We expect to be among the top stations in Europe in our class.

Edit 11. February 2015: since last time I have been operating from SJ2W in CQWW SSB and there will be additional images and writeups posted from later visits.

I went to SJ2W in northern Sweden in May 2013 to work the WPX DX CW contest with SM3WMV Micke, SM2LIY Pelle, SM2XJP Peter, and SE2T Kurt. The QTH is fantastic!  Several kms to the nearest neighbor, flat terrain and a very good antenna installations. Stacks on 40, 20, 15 and 10 as well as 4-SQ on 40m / 80m.  I have posted some pictures below. Click on the pictures to see comments for each picture. Stay tuned for more info!




10, 12 and 15 meter openings? The secrets of solar data.


Many amateur radio websites show the Solar Terrestrial Data “ticker” from N0NBH. However, many HF radio enthusiasts just look at the SN (solar spot number) and perhaps the K index. The truth is that the SN does not necessary say too much about the current radio conditions. So what should you look at to check the current conditions (more realtime information)? solarvhf.php Here is the secret: I have personally found that the SFI and the 304A as well as the X-Ray values are very good realtime clues. One example is from 21.Oct.2012. This Saturday in October 2012, the 10 meter band was wide open from early morning even as far north as Oslo, Norway. The conditions on 12 and 15 meters was also fantastic. A screenshot of the N0BNH “ticker” shows SFI well above 120, 304A well above 140, K like zero and A like three as well as an X ray index of B9,9. Note that SN (sunspots) is not near abnormally high at around 112 (keep in mind we are closing in on sunspot maximum in cycle 24 so the SN will likely be around 100 all the time). One could expect average conditions by just looking at the SN. However the conditions was nothing like average. They were very very good. What was notable from that day is the following: SFI was well above 120 so there was a strong flux, K was zero so the mag field was still undisturbed, A was 3 so the mag field had been holding undisturbed for some time, X-Ray was B9,9 and this meant that there was quite strong X ray radiation coming in, 304A was 172,5 and this meant there was also quite strong UV radiation coming in, Aurora was 1 so there was practically no Aurora activity. The conditions was fantastic on this date on all bands above 7 Mhz. So again here is the secret: don’t just look at the SN for realtime information about the HF radio conditions.

G4WPW microphone connector database


G4WPW has made a nice database covering microphone adapters for most amateur transceivers. This is a good tool for contesters and DX-ers adapting microphones and headsets for their new radios. You can check out his webpage here http://homepage.ntlworld.com/rg4wpw/date.html

Antenna isolation calculator for colocated contest / DXpedition antennas


I have made some quick isolation calculations (dB) for the scenario of two rigs with 100W output power collocated using two dipoles mounted some meters apart on the same support but with separate feedlines.

A Preliminary conclusion is that a BPF + notch is likely necessary for interference free operation. With good filters and notch, the second harmonic will be at a  7uV level and the hash will be at a S1 level on the antenna connector of RIGB which is equivalent to a moderately strong signal on 20m with low noise.  Without filters, the second harmonic will be S9+50dB. The phase noise "hash" will likely be at S3. This will likely be a significant problem.

Download the calculator here: isolation_calculator_nine_islands. The calculator is posted under a Free Beer license. You owe me a beer if you use it! Please give feedback and peer review the calculations.