Thursday, August 12, 2010

Softrock RX Ensemble Kit - Complete

I finished building the "Softrock RX Ensemble Kit" - it works!

I have been listening around the bands, mostly 20m, 40m and WWV.

There are some things that I have learned about SDR systems - I think all of this is correct, but I will correct it as I learn more:
  • A few SDR programs control the Receivers Local Oscillator and Decode the I/Q signals for display and for listening.
  • Many of the SRD programs are only Decoders of the received I/Q signals, and require a second program to set the Si570 LO - That was really NEWs to me.
  • I am going to be experimenting with other software for use with this radio.
  • Listening to a segment of the band while watching the water fall display is enjoyable and makes for quick frequency changes.
  • UPDATE: Some I/Q Decoders can control the Si570 LO, it is just not obvious.  I discovered that Rocky can control the LO, but it does it via a menu pick table - a little hard to use but it works.
  • I need to investigate each Decoder for LO control.
The configuration that seems to work best (so far) is "WinradHD" for the I/Q Decoder and "CFGSR" for controlling the Local Oscillator (Si570). It is necessary to set the frequency with CFGSR and then type the same frequency into WinRadHD, so that the displayed frequency scale is correct. I hope I am missing something here, and I hope this works better as I learn more.

WinradHD - Tuned to WWV

CFGSR - Si570 Control

Normally you set the LO to a frequency within 20KkHz of your desired listening frequency. I have been using about 6KHz difference for a start.

UPDATE - Correction: Thanks to Chris's email and the Internet, my previous understanding was WRONG. WinRadHD can control the LO directly as indicated below,  - Thanks to the very helpful folks on the Internet.

Hi Eldon,
Regarding your Ensemble II build and your use of WinradHD which I read on your blog. WinradHD can controll the softrock directly without using CFGSR, please ignore if you already know the following: Download this DLL file ( and place it in the WinradHD program folder (typically C:\program files\WinradHD\). Then start WinradHD and click on the options menu, under 'select input' you should now have an option for the SoftRock, click this and WinradHD will now control the LO as you navigate WinradHD around the bands.
Kind regards, 

 The "Rocky" Decoder was my next introduction to SDR Decoders.

Rocky SDR

I have looked at "PowerSDR-IQ", but have not got it to work correctly. UPDATE: Patrick York - KF4LMZ, sent me the following link - I need to review it as it describes the how to use PowerSDR-IQ with the Ensemble.

I am currently powering the Ensemble with a 9 Volt Battery and therefore it has little or no induced line noise (and/or ground loops). If you read this blog much, what else would you expected from me, I always use 9 Volt Batteries for my projects.

I recently found "M0KGK SDR Decoder" which looks very good and easy to use.


It is interesting that it is possible to run multiple Decoders, at the sometime on the PC - each can be turned OFF and ON to access the audio channel for operational comparison.

I also found the SDRADIO Decoder - which also looks very good, setting frequency and the audio band pass filter is "mouse click" obvious - I like it!


Note: This Decoder does not have as much of a problem displaying and decoding the centre LO frequency as the others appear, it must use some new math.

Now, maybe too many to try to use!?

See more follow up configuration information.

Note: I obtained the above images from the Internet, I hope the original owner will not mind, for each I have provided a link to their home page, via image click.

No comments:

Post a Comment