Monthly Archives: February 2012

HiQSDR as VNA

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Since today the HiQSDR or the original N2ADR frontend might be used as a vector network analyzer for the shortwave range.
Jim wrote a simple tool that displays amplitude and phase between TX port and RX port and can handle some calibration.
Currently it is quite simple and i do not have provisions to measure reflections yet, so i can just measure S21 at the moment.
But for the future it will be a nice feature to have the antenna analyzer built into the transceiver itself.
The picture below shows a simple ugly-style lowpass filter.

HiQSDR as VNA

HiQSDR as VNA

3m EME mesh dish by DG0CN

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Gert, DG0CN has send me a picture of the new 3m mesh dish design for EME usage he recently made.
It can be splitted into 6 parts for easy transport. Pretty giant antenna ;)

EDIT 2017/06/28: i got the information that Gert passed away weeks ago. His business will most probably not be continued. The webpage already has gone. RIP.

DRM TX with HiQSDR frontend

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Yesterday i used my HiQSDR frontend for transmitting a shortwave radio signal in digital DRM standard.
I had to use the FPGA firmware version 1.2 which contains enhanced filters that allow modulation of signals with a bandwidth of up to 22kHz in IQ mode (+-11kHz around the tuning frequency).
Stefan, DL2STG, did a great job creating support for the HiQSDR within the Gnuradio project. After noticing a IQ swap the 64QAM DRM signal was decodable. See the constellation diagram below.

HiQSDR DRM TX constellation diagram

HiQSDR DRM TX constellation diagram 64QAM