24 GHz EME Transverter by DB6NT


An excellent description of 24 GHz EME setup from Michael DB6NT. Originally on German, but here is Google translated on English.

Compilation of technical information about my 24 GHz EME Transverter.
Since I had tried in vain for a few years, for my 120 watt TWT TH3864C. To get power supply, I decided to walk the way with a modified RW1127 go. When converting this was the description of Manfred DL7YC and Brian G4NNS very helpful. The modification was easy and I really did a great job of 40 watts. The control output was 2.4 watts, the set one Cathode current at 135 mA. The helix current reached a maximum of 1.7 mA. A little Disc magnet in the area of the coupling also brought a little improvement the output power.

The second picture shows the measurement setup.
I was then able to set up the rest of the converter. The module as with my other EME converters, it should also be directly in the focus of the antenna (two-piece 3.7m Andrew mirror). Use for antenna switching I use a SPINNER waveguide relay that has two feedback contacts. The contacts switch on the preamplifier or the TWT as soon as the correct position of the relay is reached. This saves another sequencer. I use as a preamplifier an MKU LNA 24 243 RX2 with 1.5 dB NF which is directly connected to the waveguide switch is plugged in and is pressed with a spring.

The transverter is an MKU 24 G3 with a 12 GHz oscillator module. The oscillator is with 10 MHz connected to GPS.

The photo shows the entire internal structure of the converter. In the lower part, they are Power supplies and the TWT power supply can be seen. The antenna connection goes with one 90 ° waveguide bend down out of the housing.

The entire transverter is at a distance from one slide and one actuator parabolic mirror adjustable and can thus be optimized in the focus point. The spotlight is a scaled version of the VE4MA Superfeed (thanks to DC7KY). I have different ones measure waveguide diameter and radiator versions. The differences were there very small and difficult to measure.

The first measured values are: earth noise 3.25 dB, sun noise 14.4 dB and moon noise 1.7 dB. Measured on April 27, 2020, 17:00 UTC, at 20 ° C temperature, 45 ° Elevation and blue sky. The first echo attempts were also very promising. The echo was immediately audible despite the strong liberation and also very much in the waterfall diagram good to see.

On May 3rd, 2020 for the DUBUS Contest, I was able to do the first 6 CW QSOs. The station went surprisingly well and I had a lot of fun with the new EME band open up.

73 Michael DB6NT

Link on original article with photos: http://www.db6nt.de/fileadmin/userfiles/_pdf/download_archiv/24_GHz_EME_Transverter.pdf

Photo: from article

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