LB3HC's hightech blog

Amateur radio, RF design, electronics, uC, software, Arduino, AVR, Antennas


Roundup of SDR radios






Here is a review of SDR radios currently on the market in the low cost segment:

Posted: May 22nd, 2015 under Amateur radio, SDR. Tags: , , , ,
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More SJ2W pictures added

I have added some more SJ2W pictures


Slideshow from Ham Meeting 2015, Letohallen: Contesting from SJ2W (download as PDF)

I have uploaded my PPT slideshow from from the Ham-Meeting 2015 at Letohallen.
You can download it here (PDF): Contesting fra SJ2W (.PDF)


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

Arduino Based CW keyer / FTDI based CAT interface

I recently needed a new CW keyer with Winkey compatibility for use with my N1MM logging setup. K3NG has written some nice keyer code that I compiled and uploaded to one of my Arduino UNO boards that I had laying in the shack (if you want to try it, you need the latest  – above 1 – version of the Arduino “IDE”). Below you can see some pictures from making the prototype thru to ready made keyer with USB interface and adjustable speed button. I did not install the memory buttons, as I control the CW keyer via USB from N1MM or Hamradio Deluxe. It works very well with my Yaesu FT-450D but instead of the UNO I will eventually use a Mini Pro board with the Atmel Atmega 328. You can see more info on K3NGs site

Below is the schematic (remark: full credit is given to to K3NG!). I have modded the design for my own needs. Instead of the 2N2222 I use a TTL tolerant FET of type IRLIZ44N to drive the keyer output. Then I don’t need the 100 ohm resistors in series. I also did connect a piezo tweeter directly to the CPU  without using the 2N222 transistor. It works OK. However, the sound of the piezo tweeter is not the best in the world. Finally, as mentioned above, I did not install all the buttons. I installed only the command button to save space.  There is a need to do a small mod on the UNO hardware due to some reset issues. For that I will have to add another button that needs to be pressed when I want to upload code.


I also needed a CAT interface. It is possible to use a FTDI chip for this task, however the signal levels need to be transformed to +/- 12V. This I solved with a MAX232 board that I had laying around in the shack. So now I have a CAT interface that is compatible with Win XP, NT, 2000, 98, Windows 7, Windows 8 etc since the FTDI chips are widely supported. It looks like … but works like …



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!




Posted: May 30th, 2013 under Amateur radio, Antennas, Contesting. Tags: , , , ,
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DX clusters with internet access

DXCluster.Info - Your DX Cluster Resource Connection

It is often problematic to find a current list of DX clusters. Many lists exist on the Internet but few are updated. Also, lists in logging programs like Ham Radio Deluxe are often very old. I have found that it is best to go to the official DX cluster website and take a look at the current list.

Posted: March 23rd, 2013 under Amateur radio, DX. Tags: , , , ,
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LB3HC receives special callsign 8S7X

Latest news: The 8S7X callsign has been allocated to LB3HC.  8S7X will be activated when operating from Sweden QTH. Stay tuned for more news.




Azores Island Hunt. Captioned pictures from CU2ARA

The teams are arriving at the airport in Ponta Delgada at Sao Miguel island. A lot of luggage was brought in. Here the
Danish and German teams are waiting for their taxis. The DARC journalist is checking his photos on the digital camera as well to the left.
A too small car for rigs, linears and antennas when 9  teams arrive at the same time…
A team photo was taken in the backyard of the CU2ARA club station before teams were departing to their individual islands
Antenna and rig discussions are taking place in the backyard. The short CU2ARA tower that we used can be seen in the middle of the picture
Our guide Mr. Rui is also a pro photographer. Just look at all the cameras!
Ghis ON5NT is busy adjusting the inverted vee antenna to resonance
Marius, LB3HC is using his DG8SAQ Vector Network Analyzer to check the multiband antennas before the event.The CU2ARA members CU2IF and CU2CN and are helping out
The organizing committee is formally opening the event!
IMG_1080 Since we had a city location with some noise, we wanted to do a remote hilltop station experiment to learn from that experience for future events. After first checking with the official organizers for  approval, we travelled to one of the points in the island where there is almost 360 degrees negative horizon and no broadcast installations.This would enable a good remote location. On the above picture you can see the takeoff towards Europe. Wow! We did have some technical challenges that were solved, but the main QSO amount by far was made with the main stations down at CU2ARA. The remote station was left operational so the CU2 ops could do more work on it after the event IMG_1127  Above:
CU2CN climbs the tower on the mountaintop to put up the highest point of our sloping antenna. The antenna was sloping towards west (US).
Here is the house where the experimental remote station was mounted. We had a 100mbit/sec WLAN connection down to CU2ARA.
Another picture of the takeoff to the east (against Europe). A pretty good QTH for the remote site.  (The Azores are full of beautiful views like this. Visit to see for youself!)
Our remote station is located inside the hilltop house. A Yaesu FT857 and HRD was used. More dedicated remote systems should be used in a future event it was decided.
Here is the HRD remote screen where we controlled the hilltop remote station. This was done down in the city where the CU2ARA shack is located. (As OH2BH encouraged, we did it the innovative Arcala way!). Notice the Norwegian flag by the way!
ON5NT is working pileup
LB3HC is working pileup
The CU2ARA residents are working pileup
Our antennas downtown at CU2ARA. We used a 3 el yagi for 20 meters and inverted vees for the other bands (17 and 40).



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.