SDR on Acer Netbook, Sodira DRM.
April 2012. I recently installed SDR software on an Acer Aspire One D270 "netbook"
This has Windows 7 32 bit Starter edition, an Atom 1.6GHz dual core and 1GB memory.
It is said that netbooks do not have stereo inputs. However I discovered this Acer has a reasonable stereo system.
For a USB Softrock download the driver installer that can be downloaded at http://pe0fko.nl/SR-V9-Si570/PE0FKO-USB-Driver-Installer.exe. The installer will install the certificate and then install the driver (32 & 64 bits) then the hardware USB can be plugged in.
Setting the Audio:-
Right click the Taskbar speaker icon, "Properties"
But to find and use the Realtek Manager is better.
"Realtek HD Audio Manager" in the Start Menu.
Up to 2 channel 24 bit 192000 Hz can be selected. But although it does work at 192KHz results with SDR are poor.
Main speaker volume controls SDR TX output.
The Realtek Audio control also has these settings. Click the right icon on "Recording Volume" set Microphone Boost to 0dB.
Test by putting an unterminated cable into the mic socket, touch the tip and ring separately, you should hear a hum from each of the outputs. You may use stereo headphones but this Acer does have two speakers.
NOTE:- For SDR use "Playback Volume" above must be muted.
This netbook has an internal microphone, it is muted when an external source is plugged in but I find it is still sensitive to particularly loud noises.. No voltage is present for an electret.
Here is what you get with SDR#. This is version 212, Youssef has made it work with a small screen
June 2014:- This is an old version but the latest should still be satisfactory.
HDSDR will also just fill the screen.
The latest RX/TX version can be used for SSB with an Ensemble RX/TX. Use the onboard sound for RXTX IQ and with a cheap USB dongle for mic and audio output. The on-board output proved a little low only driving my Softrock to about 0.5 Watts.
The Acer will work at 192KHz sample rate, but is not properly useable because of the high HF noise level.
This system will work with WSPR. For clock setting, WSPR must be close to UTC. I have used a Garmin GPS18 with 1PPS and a serial>COM port adapter. ToyNtp or SatK works adequately. Possibly other utilities that just use NIMEA will work.
I find the TX audio output is low, about 0.5 watts output maximum. I will try increasing the opamp gains of my Softrock.
Maybe other digital modes with VAC, again I've not yet tried.
SODIRA DRM
Just as this shot was taken the signal dropped out, "MSC" not green. Like all things digital it is all or nothing... Not quite on tune but DRM does adjust.
Sodira works well on the Acer. It is the easiest DRM receive software. Unzip into a program folder. Like Winrad it needs the ExtIO to be placed in that folder. Make a shortcut to the application file. DRM will not decode unless the "Used sound channel" (IQ swap) is correct. Check "Configuration".
Modes are selected by using the drop-down at bottom right and the Dialog button above it.
Initial frequency set by the mouse on the keypad.
Step up and down using those buttons, the step size altered by < > buttons. the "Htun" and "Stun" alter the rate.
This DRM application has fewer features than "Dream". Program schedules will have to come from a web search. http://www.wwdxc.de/drm.htm is up to date April 2012.
More of my pages related to SDR for beginners,
http://sites.google.com/site/g4zfqradio/home
http://sites.google.com/site/g4zfqradio/configuring-a-softrock-sdr Basic details for a beginner with an assembled SDR.
http://sites.google.com/site/g4zfqradio/connecting-soundcard-sdr-to-computer Initial setup showing SDR# setup and operation Rocky. Soundcard settings, testing. AND A LIST OF A FEW LAPTOPS WITH STEREO INPUTS.
http://sites.google.com/site/g4zfqradio/sdr-with-soundcard-basic-faults More soundcard settings showing Rocky, ground loops.
http://sites.google.com/site/g4zfqradio/more-on-ground-loops-and-audio-settings With HDSDR used for illustration.