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#1
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An SDR or DDS question?
"gareth" wrote in message
... "Brian Howie" wrote in message ... http://www.radioelementi.it/public/saqrx.pdf https://sites.google.com/site/sm6lkm/saqrx/ Wow! Wow! Wow! Dev-C++ a free C++ compiler for Windows thrown in, and much smaller than MicroBloat's products! Watch this space!!!!! |
#2
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An SDR or DDS question?
"gareth" wrote in message
... "gareth" wrote in message ... "Brian Howie" wrote in message ... http://www.radioelementi.it/public/saqrx.pdf https://sites.google.com/site/sm6lkm/saqrx/ Wow! Wow! Wow! Dev-C++ a free C++ compiler for Windows thrown in, and much smaller than MicroBloat's products! Having now had time to persuse the C code, I have the answers to all my questions! I'd like to recommend to ALL readers of these NGs that they download the source code and the free C compiler whilst they are available, even if not immediately using them. Within the AudioCallBack routine is where it all happens, including the phase accumulation making the DDS for the local VFO, and the FFT. It's some years aince I've seen a Windows program done at the knife-and-fork level and so that takes me back before the times of Visual Basic, and TCL. As Brian said, it is easy to recompile and build the program again, thus giving the opportunity to dabble with the code by trying out minor edits, even if limited to the colours (colors for the yanks) of the Windows. The program clearly relies on the speed of a PC, for example, the DDS calculates sin and cos on the fly from the phase accumulator rather than using a look-up table, and I'm afraid the dinosaur in me keeps harking back to my days of assembler programming on a PDP11/20 where the slowest instruction (save for RESET at 50 mSecs) was BICB @(R1)+, @(R2)+, taking about 17 uSecs. All-in-all, this revelation by Brian is to be recommended to those who wish to see an example of DSP programming to run on a PC. Well done, Brian, and many thanks! |
#3
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An SDR or DDS question?
In message , gareth
writes All-in-all, this revelation by Brian is to be recommended to those who wish to see an example of DSP programming to run on a PC. Well done, Brian, and many thanks! Yw Someone has modified the code to use increased sound card sample rates , and add other features . https://sites.google.com/site/swljo30tb/home I can receive MSF amongst other stations on 60KHz with the 192KHz version on an untuned 5ft loop antenna I use on MF. Brian -- Brian Howie |
#4
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An SDR or DDS question?
"Brian Howie" wrote in message
... In message , gareth writes All-in-all, this revelation by Brian is to be recommended to those who wish to see an example of DSP programming to run on a PC. Well done, Brian, and many thanks! Yw Someone has modified the code to use increased sound card sample rates , and add other features . https://sites.google.com/site/swljo30tb/home I can receive MSF amongst other stations on 60KHz with the 192KHz version on an untuned 5ft loop antenna I use on MF. The accompanying PPT is in foreign, presumably Swedish, but there is an interesting page showing the VLF antenna, and the interest to me comes from numerous tappings along the antenna with a coil down to ground. An early form of loop antenna, perhaps? Is there scope here for experiments on similar such tappings to bring a Top Band antenna down to a size to fit a suburban garden? |
#5
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An SDR or DDS question?
"Brian Howie" wrote in message
... Someone has modified the code to use increased sound card sample rates , and add other features . https://sites.google.com/site/swljo30tb/home I can receive MSF amongst other stations on 60KHz with the 192KHz version on an untuned 5ft loop antenna I use on MF. OK, thanks, I've grabbed that too. Enough code browsing to keep me off Usenet for a few days :-) Cue: You know what! |
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