Category Archives: SDR

V/U/SHF Contest from JO60OM

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23cm setup with HiQSDR…

HiQSDR 23cm

HiQSDR 23cm transverter setup

Contest from Hirtstein. Qrv mainly on 23cm. Setup was composed new. The old 10m-23cm TRV, 2x100W PA, 1.5m dish, backside Quados-8. Changed the Transceiver to my HiQSDR. Seeing the complete Band at once is pretty nice. CW was done completely by keyboard out of VUSC. SSB voicekeyer also worked via a small audio switchbox made for that purpose. Problems upfront were dynamic microphone headsets not working properly with the soundcard input. In addition Murphy made my linear powersupply fail during testing the equipment which lead to a damage of the transverter. Luckily it was not too terrible ;)

DARC 10m Contest

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DARC 10m contest from Triebenberg JO61XA.  Rig: Hiqsdr, 100W class C amplifier, 2x deltaloop. Software: Quisk, forwarding 192kHz to CW-Skimmer, TLF filling the bandmap from the CW Skimmer spots and controlling Quisk. CW keying via cwdaemon.

I worked 49 QSO and about 1800 points. Points for improvement:

– change both antennas to horizontal

– use a passive switch for the antennas since the 12v->24v caused interference

– improve the filters for the bandmap (avoid hp stations, highlight multies)

The wheather was quite stormy and i had problems with the fibre mast. Conditions were very good with band wide open.

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DUR April 14

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2014 04 DUR 23cm setup

2014 04 DUR 23cm setup

rotor control + hiqsdr

rotor control + hiqsdr

With hiqsdr, transverter and new rotator control on 23cm. Low activity but nice weather.

I decided to try some new setup. The recently completed rotator control was used with VUSC to turn the antenna to the destination automatically. I was first time using my HiQSDR setup portable with a 23cm-10m transverter borrowed from DL3JAN. Therefore i skipped 13cm/9cm.

The last picture shows a screenshot of the signal from DL1DXA at the end of the DUR test.

Screenshot DUR 04/14

Screenshot DUR 04/14

HiQSDR repaired…

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A while ago i destroyed the RX input amplifier of my HiQSDR. Last weekend i replaced the two hittide switches and the differential amplifier of that circuit. Now its fully operational again. On the photo you see the backside of the HiQSDR enclosure as well as my antenna tuner and the SWR/Power meter. The transceiver itself does not have any human interface. It just has inputs for power, RF, key and PTT and outputs for RF, PTT and some control signals.
The digital baseband goes via UDP connection to the SDR PC. Usually i use my Laptop connected via Wifi.
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HiQSDR – Quisk – TLF – cwdaemon …

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I tried to build something useful out of the equipment flying around here. My HiQSDR can now transmit in CW mode via external keying. Output power is about 10W maximum. The software is quisk which can be controlled by the very nice TLF log software via the hamlib library. TLF gets spots from the reversebeacon network to fill its bandmap which is afterwards browsable via shortkey. Quisk then tunes to the station automatically. In addition TLF can use the cwdaemon to generate CW signs via a serial port. With cwdaemon running on some embedded hardware close to the HiQSDR it would be possible to have the SDR PC somewhere just connected via the wireless network running all the control and audio remote. Find a screenshot below.

Quisk, TLF and cwdaemon running a HiQSDR under Linux

Quisk, TLF and cwdaemon running a HiQSDR under Linux

DUR Contest May & WebSDR

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This time DUR contest together with Steffen DJ5AM.
QRV on 23cm, 13cm, 10GHz, partly 24GHz.
Not very much DX on 23cm this time but some nice 10GHz QSO with the station of Steffen.
I made a short video receiving my 23cm signal with the WebSDR located at my home QTH.

DUR Contest May 2013 - receiving myself on my 23cm websdr
Watch this video on YouTube.

The WebSDR is a test and receives 23cm & as well as 10GHz using 2x RTLSDR USB sticks.
PA3FWM kindly added support for these types of USB receiver sticks which makes it very easy to setup WebSDR receivers for the bands between 24MHz and 1700MHz. One is connected to a crystal stabilized sat LNB which makes the receiver for the narrow band section of the 10GHz ham band.

As long as the receiver is online you can find it here:
http://dh5ym.hopto.org:8901

The following pictures show my 23/13cm equipment after then end of the DUR test ready to go home and the 10GHz and 24GHz station of Steffen, DJ5AM.

DCIM100MEDIA

DCIM100MEDIA

Low cost 10GHz reception

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Some days ago i found a nice video clip from an italian guy who used a cheap DVB-T stick (RTLSDR) in combination with a crystal stabilized sat-TV LNB for some 10GHz hamradio experiments.
A short search brought up a nice paper about some investigations of G4JNT who investigated the frequency stability and phase noise of one of such LNBs and found that it could be used for narrow band reception in amateur service. It can be found here: http://www.g4jnt.com/PLL_LNB_Tests.pdf Since i already have some experience with the RTLSDR stuff and currently experimenting with 10GHz as well i decided to give this ultracheap setup a chance. I purchased a LNB (which was told to have crystal stabilization) for about 7 Euro and made a phantom feed for that. With just the 12V applied to the coaxial cable it works in the lower band and the polarization is in the direction of the antenna connector. 10386MHz falls to about 618MHz since there are no sharp filters inside the LNB it is possible to receive some ham signals.
The picture shows the reception of the local beacon DM0TUD. Its not very strong here since it comes in via reflection at the other side of the city. With my 60cm dish its about S8. The LNB i use without any dish just placing it onto the cupboard.

LNB + RTLSDR receiving DM0TUD on 10GHz

LNB + RTLSDR receiving DM0TUD on 10GHz

crystal stabilized sat-LNB

crystal stabilized sat-LNB

Find here a short video that give an impression how it sounds like.

https://www.youtube.com/embed/SJlcb0t2GGw

The signal sounds a bit ugly because of the LNBs oscillator phase noise. The frequency of the LNB was quite stable after half an hour of operation. The LNB was just lying on the cupboard and used as it is without any dish. I have no direct line of sight to the beacon and i receive the signal just via reflection at the other end of the city. Therefore you can notice some fading.

Edit: When opening the LNB i found that it has DROs and not as advertized on the package a crystal stabilized oscillator. For DROs its working quite well but since its stated even on the package that it should be “crystal controlled” its obviously a fake.

Edit 2: Today i received another LNB. Its a Octagon Optima model OTLSO as measured by G4JNT. I made a new video of the reception of the DM0TUD 10GHz beacon under the same conditions as before. The sound is perfectly fine now.

http://www.youtube.com/embed/TLwpWbVw5jo

RTLSDR with OpenWRT

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Last days i spend some minutes getting the RTL_TCP server running with OpenWRT Backfire on one of my WGT634U routers. These routers have a USB2 port and i can connect my NOXON DAB Stick directly.
I crosscompiled the packages. The sources and a Makefile for the OpenWRT build system you can get from the Osmocom page. You definitively need libusb for getting it running.
For the brcm47xx plattform you can find the both packages here:
librtlsdr_0.1.0-1_brcm47xx.ipk
rtl-sdr_0.1.0-1_brcm47xx.ipk
Attention: The both packages have not been added to my Packages file in the directory. So you have to copy them manually and install them to your OpenWRT. The dependencies are resolved automatically.
After that you probably need to configure the firewall on the router to pass port 1234 to the outside and the RTL_TCP server needs to be started with option -a #lan-interface-ip#, otherise the server will listen to localhost only. With my WGT634U i experienced that i cannot set the samplerate to 2MSpl/s. In this case the router reboots after a few seconds. With 1MSpl/s it worked smooth so far.
With running the server on a embedded system you can install the frontend at a completely different location than the client.