beacon DL0SHF

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My new setup for receiving DL0SHF on 10 GHz EME

 

I have build myself a receive system for DL0SHF.

In november 2014 I started with a new setup using a PLL LNB and a 60 cm offset dish, more info will follow as I am proceeding.

My Receive system is based on a 48 cm Procom dish, a DB6NT pre-amp with 0.7 dB nF and a DB6NT transverter.

This is mounted on a small gearbox Az-El which is for sale as a gearbox for telescope mount for astronomy

Today 30-3-2014 I received DL0SHF beacon with my new setup. It was performing better than my previous setup with a 50 cm dish being my portable station and not as well defined for EME.

Listen to the signal received from DL0SHF in CW

listen to the JT signal from DL0SHF

Download the SDR recording for Spectravue

Please keep in mind that the different Spectravue pictures from signals have been made on different days
which makes it difficult to compare, because moon distance and libration spreading is different

CW signal in Spectravue 14dB S/N in 12 Hz bandwidth plot scale is 2 dB/div

 

 

The JT signal from DL0SHF Plot scale is 2 dB/div

The decodes from the WSJT signal from DL0SHF (Using WSJT7)

 

On 1-4-2014 I did a test in receiving DL0SHF on low power

I think I found the signal but just a bit too weak to decode

I did not understand because in my opinion I missed about 6 dB

After contact with the first operator from DL0SHF he confirmed that beacon power had significantly reduced from 50 to 8 W

 

On 3-8-2014 I received DL0SHF on low power (after repair of the 50Watt PA)

Signals were weak but could be found in Spectravue

CW signal was audible but much too weak to copy

CW signal, the two FSK signals are visible, S/N about 2dB@12Hz resolution bandwidth

JT signal the 4 tones are visible in the waterfall

The JT signal was good to decode (using WSJT9)

 

Other Signals

I did also a test with Charlie G3WDG to try copy his signal with my small dish

Station from Charlie G3WDG consists of a 3 mtr Andrew dish and 50 W output

 

I found his signal instantly in my SDR

About 3 to 4 dB S/N ratio in 12 Hz bandwidth

This is the first signal I received from G3WDG The plot scale is 1 dB /div

We tried a test if it was possible to take the CW but this was too difficult, the CW tone was audible but just too weak to be able to copy the CW

Then we tried WSJT with good decodes

 

During the DUBUS 3 cm EME contest I found signals from more stations

OK1KIR and SP1JLW

 

Take a look at my system.

I use a small gearbox from IOPTRON designed for small astronomical telescopes.
main advantage, it has all calculations available for moon and sun positions.

Just calibrate and then aim to the sun or the moon and it's tracking, you cannot get it more easily

similar drive available via Robtics

Ready for RX

Click on the picture to see a small movie of the dish turning

 

This is my receive system

I use the funcube dongle in combination with Spectravue

After building my receive system I did some testsing to be sure my setup was working

I measure 3,3 dB solar noise with this setup Plot scale 0.5 dB/div

Looking at the results from the VK3UM calculator I should be able to get 0.1 dB moon noise

With Spectravue in continuum mode I tried to measure this moon noise Plot scale 0.1 dB/div

Life demo during EME 2014 conference receiving DL0SHF high power

Audience was much bigger than expected, sorry for little time to explain to individuals
Luckily my system was working fine with instant copy of DL0SHF
Especially thanks to Per, DK7LJ for putting on DL0SHF at high power
Signals coming in were fine but a bit weaker than before
CW signal was speaker copy (much noise from all visitors talking)
Probably solar noise was causing degraded performance, offset between sun and moon was very small

The second demo for receiving DL0SHF on low power was cancelled due to the rain.
also there was a big chance off failure due to sun still too close to the moon causing sun noise

My presentation during EME 2014 conference

Look at Youtube for my presentation during EME 2014:

 https://www.youtube.com/watch?v=rsxkfHfrN7k&feature=youtu.be

https://www.youtube.com/watch?v=tkzcagOWSBo
 

Report from OK1TEH from the EME 2014 conference
http://www.ok2kkw.com/00003016/eme2014/eme2014bodou_eng.htm


Report from OK1TEH about my presentation during EME 2014

6) Receiving 10 GHz EME with small equipment
Hans van Alphen PA0EHG

This presentation was for me as well as for big number of conference participants the most interesting lecture at French EME meeting. Hans, PA0EHG presented possibilities of receiving EME signals with subminimal setup for 10 GHZ band, which in this case was only 48 cm diameter dish with LNA at feed, transvertor and SDR RX for IF. This has been possible mainly thanks to DL0SHF's QRO beacon which is on air since December 2013 and use 7,6 m dish with 50W TWT PA including the possibility  (on request) to increase RF power output up to 550W (!) out. Hans introduced in the lecture program SpectraVue Ver 3.15, which he found to be the best program for detection of the weakest signals EME, played audio recordings of the tests with DL0SHF and prepare for the next day live demonstration of EME signal reception on DL0SHF's beacon in front of PB8 telescope. The weather finally got better for about 3 hours so everyone interested could listen to live 3 cm CW EME signals from a 48 cm dish by it's own ears. The most important conclusion of the lecture was that the biggest problem is the proper alignment of the antenna to the Moon. Hans used smart solution of this problem by using digital rotator unit, which is manufactured for automatic rotation of small astronomical telescopes, including GPS receiver. This small rotator can be bought for 200$ (a version without GPS for only 100 US dollars).

More at: http://home.planet.nl/~alphe078/receiving-dl0shf.htm

Lecture and successful demonstration of PA0EHG's small 3cm EME station in front of the conference house was met with great interest and it is likely that it could result in increase of the active EME stations on this interesting EME band.

 

These are the calculations of the VK3UM calculator.

In the calculation for DL0SHF I degraded the antenna performance to limit gain to 52 dB
 as stated in the article "what's different on 10 GHz EME"
Reason for this is that the antenna from DL0SHF is that big that it's beam only hits part of the moon.

The important value's are marked with a red circle,
the TX data from home station are valid for DL0SHF and the RX data for the DX station are for my system

Calculation for the high power transmissions from DL0SHF

I should be able to get 17,3 dB S/N in 12 Hz bandwidth
Solar noise is 3,4 dB
Moon noise is 0.1 dB
Antenna gain DL0SHF limited to 52 dB

Calculations for G3WDG

I should be able to get 3,2 dB S/N in 12 Hz bandwidth