C-band Receiver Station

This page describes the work-in-progress design of an SDR based receiver station for the 5.8 GHz band, originally created for tracking the UNITEC-1 spacecraft on its interplanetary journey to Venus.

Event logbook is available on the talk page.

UNITEC-1 is the first interplanetary spacecraft built by university students. It will be transmitting telemetry using OOSK at 1 bps in the 5.7 GHz amateur radio band using a 10W RF into a pair of patch antennas. UNITEC-1 operators need the help of the global amateur radio community for tracking their spacecraft during its journey to Venus. Antenna pointing and Doppler shift measurements will be used for estimating the interplanetary trajectory of the craft.

Parabolic Dish
To be written...

Wide-band Feed
To be written...

Low Noise Down-converter


Kuhne Electronic had several options for 5.8 GHz LNC that covers the whole 5.65...5.85 GHz range:
 * MKU LNC 57 &mdash; converting 5650...5850 MHz to 1450...1650 MHz, 1 dB NF and 50 dB gain
 * MKU LNC 57-3 &mdash; converting 5600...5900 MHz to 1400...1700 MHz, 1 dB NF and 40 dB gain
 * KU LNC 5659 C PRO &mdash; converting 5600...5900 MHz to 	 400...700 MHz, 1 dB NF and 40 dB gain

We have about 40 meters of H1000-class (TBC) cable running from the Dish to the control room and using 1.4-1.7 GHz as first IF would result in too much loss. Therefore, we chose the 5659 PRO version which has output in the 400-700 MHz range where the cable loss is limited to 6 dB (TBC).

The LNC is supplied via the coax cable. DC viltage is injected into the coax using KU BT 271 N bias-T from Kuhne. We also had something called MSTTR001 from Snec but that is believed to work up to 100 mA, while the LNC typically requires 180 mA.



Receiver
To be written...

The receiver is based on the Universal Software Radio Peripheral (USRP) and GNU Radio.

Since our first IF is 400..700 MHz we have the choice between the TVRX and the WBX transceiver boards:

Software
To be written...

System Tests
To be written...

2010.03.23
First time we powered up the LNC.

We were hoping to receive OZ7IGY beacon on 5760.930 MHz but in the OZ7SAT building we could only receive it while an airplane was passing by (reflection).

We will try again next week on the roof which will hopefully give clearer line of sight to OZ7IGY.

We could detect signal from an 5.8 GHz signal generator, though the generator was not suitable for quantitative measurements.

Detailed Report

2010.04.13
Planning a new session where we will attempt reception of OZ7IGY.

2010.04.24
European EME Contest on 5.8 GHz.

Blogs

 * 2010.03.12: UNITEC-1: A New Deep Space Adventure
 * 2010.03.16: UNITEC-1: The KU LNC 5659 C PRO has arrived
 * 2010.03.17: Technical papers about UNITEC-1
 * 2010.03.17: Bias-T for the UNITEC-1 Receiver
 * 2010.03.21: Simple CW Receiver with GNU Radio
 * 2010.03.23: Simple CW Receiver V0.3
 * 2010.03.24: Successful first tests of the UNITEC-1 receiver setup
 * 2010.03.24: WBX receiver sensitivity in CW
 * 2010.04.01: From double side band to single side band reception
 * 2010.04.06: Simple SSB Receiver in GNU Radio Companion

Videos

 * 2010.03.15: Unpacking the LNC: YouTube or Ustream
 * 2010.03.21: Simple CW Receiver with GNU Radio: YouTube
 * 2010.04.05: GNU Radio Companion: Simple SSB Receiver: YouTube