2023 June UHF/SHF Contest from JO60OM

Our local club DARC chapter S07 participates in the DARC Club competition. See our results page here (external).
Because of the UHF/SHF contest and the CW Fieldday both contributing to the Club competition we went to our portable QTH in JO60OM. There is a great mix of high altitude and very nice accomodation. Find some report of DL6JZ here.
Because of some family struggle i went to my parents home already friday evening. From there its only a half hour trip to Hirtstein. We met in JO60OM around noon and started to put the equipment. This time i took my 1.5m dish for 23cm and the 1m dish was planned for 13cm. Fred also brought his 6cm and 3cm systems.
The 23cm was my favourite configuration with 2x 100W (one for front system and one for the backside), the 23cm transverter with 10m IF and my HiQSDR. The Quisk SDR waterfall gives a good overview about the band and aircraft scatter can easily be identified.
For 13cm my transverter masthead box with the 75W amplifier was used. Its the same that was already used first last year. Together with a PTT splitter it was possible to connect my old 5W 9cm system to the same 1m dish as well. This was working better as expected.
On 6cm we had a very well working system with a old IC202 as IF transceiver. Despite not beeing used for quite some time it was still doing great.
For 3cm the feed was missing unfortunately and so we skipped the band entirely.
Surprisingly all systems where up and running at the beginning of the contest.
The focus was planned to be on 23cm because this band counts for the DARC CM. All other bads where add-on for the DARC UKW Contest Pokal OV competition.

23cm right, 13/9cm and 6cm left.

23cm place with SDR PC right and log left.

place for 13, 9 and 6cm operation.

The activity saturday afternoon and sunday morning was quite good. But i had some impression that the activity from OK which was always great is somewhat declining in the recent times. Its a bit compensated by the IC9700 effect.
In addition to the microwave activity i was planned in for some lightwave tests saturday evening. Jo DL3ARM does a great job motivating an increasing group of enthusiasts to try communication with visible light. So i took my old laser station to the hill. The decision was absolutely good since the weather turned out to be almost perfect.
Jo was on the Fichtelberg JO60LK which is only about 20km from our location. We found each others light very fast and completed the QSO in AM within minutes even during the sunset. It was great to hear his modulation and i think it was my first voice QSO via light. I took a short video of his on-off beacon signal demodulated at my station. The loud noise is some 70cm APRS on the talkback frequency we had choosen.

The next foto shows my red light as seen by Jo DL3ARM on Fichtelberg.

My light from JO60OM as seen by DL3ARM in JO60LK

After that QSO i had an unsucessful attempt with DM5D (Wetterberg) and DL3ALF (Trageser Halde). During investigations later the next week i found that the path to DM5D is unlikely to work due to going through trees in between. But the path to DL3ALF should have had perfectly worked. The problem was likely that our preparation had room for improvement. From Trages you cant see the chimney in Chemnitz which is a prominent landmark due to its colorful lighting in the night. This and the cold wind and darkness on the tower there makes it very diffcult to find the right direction. Therefore we missed this slot.
The path to DL0MLU on the Petersberg close to Halle seems too far as well. But one more QSO i was happily able to complete. With DR7B (Rene DL2JRM) i was able to complete a very nice 65km AM QSO after some minutes of mutual searching the horizont. This was a new light ODX for myself and i am very happy about that. Unfortunately i missed to take a video :(
After storing away the light rig i continued with 23cm to about 0030UTC. Then there was nobody to contact anymore in the ON4KST chat and i decided to take some sleep. I only started operation again from lunch to the end of the contest.

The result with claimed scores is:
23cm: 89 QSO (some dupes), ODX HA8V 680km => 3rd in DL SOP
13cm: 25 QSO, ODX ON4CJQ/P 580km => 4th in DL SOP
9cm: 14 QSO, ODX OE5VRL 240km => 4th in DL SOP
6cm: 10 QSO, ODX OE5VRL 240km => 1st in DL SOP
Light: 2 QSO, ODX DR7B 65km => 2nd in DL SOP

Next time will likely be only some QSO from home in July.

Some maps:

23cm 23/06 – Kartendaten: OpenStreetMap-Mitwirkende, SRTM | Kartendarstellung: OpenTopoMap (CC-BY-SA), DL4MFM log analyzer

13cm 23/06 – Kartendaten: OpenStreetMap-Mitwirkende, SRTM | Kartendarstellung: OpenTopoMap (CC-BY-SA), DL4MFM log analyzer

9cm 23/06 – Kartendaten: OpenStreetMap-Mitwirkende, SRTM | Kartendarstellung: OpenTopoMap (CC-BY-SA), DL4MFM log analyzer

6cm 23/06 – Kartendaten: OpenStreetMap-Mitwirkende, SRTM | Kartendarstellung: OpenTopoMap (CC-BY-SA), DL4MFM log analyzer

PlutoSDR operation and some microwave beacon

Below i add some short videos i made. The first two show transmit and receive operation of the PlutoSDR in the 6cm amateur band. I used the great sdrangel software. The opposite side is my normal 6cm rig consisting of a FT-817 and a DB6NT transverter.

The third video shows 3 of the DM0TUD microwave beacons that are located close to my home. It is from right to left: 13cm (FT-290), 3cm (FT-790R2), 9cm (FT-817).

Searching for some FreeDV QSO partner on VHF

Since i use Quisk for my HiQSDR i found it interesting to experiment with FreeDV again. Quisk can directly support using the FreeDV API and work in this digital mode without building lots of cables. Since i wanted to try the latest mode 700C i had to compile the library from the scratch and add the mode to the configuration of quisk. Below you can find recordings of my CQ call in the modes 1600 and 700C which were made loopback.
Now i search for a QSO partner preferably on 2m somewhere in the area around JO61. I can work relatively well direction southeast. So east OK might be good.

Mode 1600

Mode 700C

Please remember the 700C mode uses only 1kHz of bandwidth.
If you are interested in some tests just send me a email to dh5ym@darc.de

March 16 V-/U-/SHF contest JO61VB

This time i had to stay home. I used the little time to check the equipment for 2m.
In the end i had 37 QSO in about 3 hours of operation time. Not a lot. Given that i just use a omni antenna i am still fine.

March 16 - stations reached

March 16 – stations reached

I used my HiQSDR + ME2HT setup. This time i used a Odroid board with cwdaemon for keying. With that the rig can be placed anywhere in the house and the SDR/Log PC can be connected via wireless LAN. This enables contest operation from the couch without annoying the family by loud fans or clicking of RX/TX relais.


Last weekend i was able to participate in the Marconi Memorial VHF Contest. First of all many thanks to DL4DTU and DL3DTS for giving the possibility to use their great QTH in JO60TR together with the antenna group 4x9ele + the amplifier !

I used my HiQSDR already few contests before. Now i wanted to try on 2m as well. I decided to purchase a ME2HT-Pro transverter which perfectly fits the transverter input/output of the transverter. You can see the setup on the picture below.



The SDR is controlled from the Quisk software. I usually use 196kHz bandwidth setting. This time i tried the CWSkimmer software. Quisk can forward the received baseband samples to a audio loopback device which is fed into the skimmer running under Wine.

The first time i used the very powerful Tucnak log from OK1ZIA. The log got the skimmer spots. In addition also Quisk connects to the skimmer. If the center frequency shifts Quisk tells the skimmer the new center frequency. This is required to always get correct spots. From the bandmap and the cluster window of Tucnak its directly possible to control Quisk like a hardware transceiver. In addition Quisk has a 2nd RX that can be used  to listen to other frequencies in between the CQ loops. The picture shows the SDR PC on the right side and log PC on the left side. On request of some OM i also fed the skimmer spots into the reversebeacon network. Sometimes i had the impression that this caused sometimes other stations beeing faster than me ;)

Log and SDR PC in JO60TR

Log and SDR PC in JO60TR

The big advantage of the skimmer connected to the local system was that i immediately noticed when DX stations were heading their antennas in my direction. Looking through the skimmer spots i noticed that i still missed quite some station from DX.

To avoid turning the antenna array all the time i decided to use a second antenna system. In addition to the 4x9ele of Norbert i mounted my DK7ZB-Oblong to one of the other masts at the QTH. The array ran with about 400wtts and the omni antenna with about 200wtts. Reception was selectable from either the one or the other antenna.

Overall the setup was working quite well. The only part that really caused a lot of trouble was the sequencer required to switch the various relais in the correct order. The microcontroller in the setup had problems to keep the PTT. Impulses from the switching relais caused the PTT input of the sequencer to raise for a short moment and afterwards the PTT was not detected anymore. Sporadically my transmissions got interrupted by that effect. Sorry for that. In addition i had some minor trouble configuring all the software correctly since the IP network setup was quite different than at home. I also had to extend my wireless internet access 2 times. One time because the Windows VM with the aggregator software wanted to download a Windows10 update ;)

In the next picture you see the map of the worked stations. The result was about 250QSO and a bit over 80000 points raw score with a average of about 300km per QSO.

QSO map mmc2015 from JO60TR

QSO map mmc2015 from JO60TR

Last but not least i want to show some spectrum screenshots from the contest.

The Erzgebirge is known to have a high density of VHF contest stations from OK and DL. Therefore the band is very full.

waterfall mmc15

waterfall mmc15

Within the waterfall history its a lot easier to find a free frequency than with a normal transceiver. You also see in which direction you need to move if one of the other close high power stations comes too close. For the close high power stations you can also see the problems of the different transmitters that can cause wideband interference.

Example 1: Phasenoise of the transmitter

poor TX phasenoise

poor TX phasenoise

This is really a poor example since the noise is less than 70dB below the carrier.

Example 2: Keying clicks causing splatters

keying clicks

keying clicks

In that example the spectrum of the oscillator is a lot better. But the hard keying of the TX causes leakage to other frequencies about 85dB below the carrier. The level was rather low but remember the proximity and the high antenna gain and TX power.

I wonder if someone can give me honest feedback about my own TX signal…?

73 de Mario, DH5YM

Tucnak, Quisk, HiQSDR, skimmer

In preparation for the Marconi memorial contest i tried to improve my setup. I use my HiQSDR with Quisk. Since a few versions Quisk has a built in DX Cluster client. Quisk forwards its baseband samples up to 192kHz bandwith to the skimmer and i managed to send the skimmer/lo_freq command if the center frequency of my hardware changes. The nice thing is that all decoded calls are printed right below the waterfall. The rest is reading the skimmer into the very nice and powerfull Tucnak log of OK1ZIA. The software mainly is a log for VHF/UHF/SHF contest operation. Lada also implemented a nice new feature. Now its possible to zap through the calls in the bandmap with ctrl-arrow and Quisk is automatically controlled via Hamlib. Further features of Tucnak are integration of ON4KST chat, airplane scatter prediction, cw keyer, ssb keyer, recording of all contest audio and a lot more. It can also work in environments with multiple stations connecting several Tucnak logs together. Available for Linux, Windows and Android.

Tucnak + Quisk


Odroid U3 WebSDR

I want to run a temporary 4m WebSDR. The software comes from PA3FWM and there is a binary for raspberry pie computers. The binary can run on any ARM CPU. I purchased a Odroid U3 which has a lot more CPU power. The picture shows the Odroid as well as the rtlsdr connected and a wifi stick used for connecting to my network. Running the WebSDR with 1MHz bandwith gives about 50% CPU load.

The board runs Lubuntu 14.04.2. I did not measure the current consumption on the 5V supply.

My aim is to put it in a box to the balkony.


Today i heard my first station on 4m with that setup. SV2JAO.


Rainscatter 20150704 July contest on WebSDR

Saturday evening there were strong scatterpoints west and northwest of Berlin. Since the same time there was the July V/U/SHF contest this gave amazing scatters from the contest participants. I listened with our local 10GHz websdr and did some recordings and screenshots. Please see below…

Stations heard were:


Screenshot - 04.07.2015 - 21_37_27 Screenshot - 04.07.2015 - 21_23_49 Screenshot - 04.07.2015 - 21_15_19 Screenshot - 04.07.2015 - 21_13_35 Screenshot - 04.07.2015 - 21_03_50 10ghz_Screenshot - 04.07.2015 - 20_58_39