Review KU LNC 8085 C PRO, Down Converter from Iban, EB3FRN

In the last decades the different space agencies are launching space probes for planetary and asteroid research. For the communication and data collection there are multiple ground tracking stations, which form the Deep Sspace Network (DSN). The communication are peformed in the S,
X and Ka bands [1][2].

One of the most exciting activities in the field of amateur radio science is the tracking and reception of space probes from the Deep Space Network. Since these signals are often hundreds of millions of kilometers away, the detection of a signal alone is a challenge in itself [3] [4].

Recently Kuhne Electronics has launched to the market the LNC8085_C_PRO. It is a converter that allows us to downconvert X-band signals (8.4GHz) to an IF in the UHF band (from 200 to 1300MHz) totally plug&play [5]. I have had the opportunity to test a unit of the LNC8085_C_PRO
for several weeks, making it my primary X-band receiver for Amateur-DSN [6].



The first impression is very good, it is a well designed, is robust and a high quality product. I was impressed that the case was waterproof, something important if you are going to use it permanently outdoors. From my point of view the highlights of the converter are a very low noise figure which allows to use the converter without additional low noise amplification, high stability local oscillator with very low phase noise and frequency selectable ,power and IF over the same cable with additional IF amplification for very long cable lengths.


For the test I have mounted the converter directly to the illuminator of my 2.4mts offset dish without any additional LNA. The cable run is 15 meters of rg213 and as intermediate frequency I’ve used an AIRSPY R2 with different programs like SDR#, SDR++ and baudline, also a
RFSPACE NETSDR with Spectravue.

     

Once the converter was mounted, the first thing to do was to verify the solar noise, obtaining a measurement of 12.3dB (SFU of 83 at 10.cm), which is a very good result, considering that the converter is connected directly to a coaxial waveguide transition without LNA.

Although the converter has no external reference input to discipline it, it has a very good stability, with only some jitter noticeable with a span of a few khz in the FFT waterfall in long term.

30-minute of signal in the FFT waterfall of the DART space probe with a span of 8kHz:



30-minute of signal in the FFT waterfall of the Stereo-A space probe with a span of 70kHz:



During the test period of the converter we have assisted to the launching of the Lucy [7] and Dart [8] space probes which we have been able to receive their data transmitted up to aprox. 1 million kilometers away!

Some radio amateurs like EA4GPZ [9] [10] have managed to demodulate and decode some of the frames sent by the probes, using recordings in which the converter has been used, so the jitter has not been a problem and the phase noise very good.





Also another other probes were also successfully detected, such as the Mars Odissey, Mars Ressonance Orbiter (MRO), Bepi Colombo, Stereo-A and Juno.

Detection of the Sonda Mars Odissey space probe orbiting Mars at 370 million km away:



Detection of the Mars Ressonance Orbiter space orbiting Mars at 370 million km away:



Detection of the BepiColombo space probe traveling to Mercury at 228 million km away:



Detection of the Juno space probe orbiting Jupiter at 770 million km away. My best ODX with the Kuhne!



My conclusion is that it is a highly recommended product for anyone interested in space communications. Especially for moon bounce or satellite enthusiasts, it allows them to broaden their horizons using part of their existing infrastructure. Undoubtedly in the next years we will live a new space race and the amateurs also have to be part of it! [6].

73! de Iban, EB3FRN
Decmber of 2021

References:
[1] https://www.nasa.gov/directorates/heo/scan/services/networks/deep_space_network
[2] https://eyes.nasa.gov/dsn/dsn.html
[3] https://youtu.be/p5lGK4a_uv4
[4] https://youtu.be/gcYew7JhCLU
[5] https://shop.kuhne-electronic.com/kuhne/en/shop/new/KU+LNC+8085+C+PRO+
+Down+Converter/?card=2089
[6] https://groups.io/g/Amateur-DSN
[7] https://en.wikipedia.org/wiki/Lucy_(spacecraft)
[8] https://en.wikipedia.org/wiki/Double_Asteroid_Redirection_Test
[9] https://destevez.net/2021/10/decoding-lucy/
[10] https://destevez.net/2021/11/decoding-dart/