Re: [digitalradio] FIR Filters
Hi Sergio, I am able to design using Parks-McClellan and to be honest I think my UI is better than ScopeFIR's. What I would like (but not essential) is the ability to take my filter coefficients and validate them with another program. I don't see this in ScopeFIR, although I could possible write my own code to do what I want I need to validate my filters with a program not created by my own fair hands :-) With a filter covering 0 to 4,000Hz I simply feed a signal in, see what I get out and do some sums... Simon Brown, HB9DRV - Original Message - From: [EMAIL PROTECTED] I have tried ScopeFIR so far.
Re: [digitalradio] FIR Filters
Since the filter coefficients are the impulse response, you should be able to do a DFT of the coefficients to get the frequency response. 73, John KD6OZH - Original Message - From: Simon Brown To: [EMAIL PROTECTED] Cc: digitalradio@yahoogroups.com Sent: Monday, January 21, 2008 08:46 UTC Subject: Re: [digitalradio] FIR Filters Hi Sergio, I am able to design using Parks-McClellan and to be honest I think my UI is better than ScopeFIR's. What I would like (but not essential) is the ability to take my filter coefficients and validate them with another program. I don't see this in ScopeFIR, although I could possible write my own code to do what I want I need to validate my filters with a program not created by my own fair hands :-) With a filter covering 0 to 4,000Hz I simply feed a signal in, see what I get out and do some sums... Simon Brown, HB9DRV - Original Message - From: [EMAIL PROTECTED] I have tried ScopeFIR so far.
Re: [digitalradio] FIR Filters
Hi, This is not a problem, but I would like to feed my data into a 3-rd party program to prove my design, that's all :-) Simon Brown, HB9DRV - Original Message - From: John B. Stephensen Since the filter coefficients are the impulse response, you should be able to do a DFT of the coefficients to get the frequency response.
Re: [digitalradio] FIR Filters
Simon, You can use znudigi to do this. See http://wa5znu.org/2008/znudigi-rpsk You will need to recompile it, but it is in Java and the source is provided. The FIRFilter is there, and the designer is separated out. Leigh/WA5ZNU On Mon, 21 Jan 2008 12:46 am, Simon Brown wrote: Hi Sergio, I am able to design using Parks-McClellan and to be honest I think my UI is better than ScopeFIR's. What I would like (but not essential) is the ability to take my filter coefficients and validate them with another program. I don't see this in ScopeFIR, although I could possible write my own code to do what I want I need to validate my filters with a program not created by my own fair hands :-) With a filter covering 0 to 4,000Hz I simply feed a signal in, see what I get out and do some sums... Simon Brown, HB9DRV - Original Message - From: [EMAIL PROTECTED] I have tried ScopeFIR so far. Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked DRCC contest info : http://www.obriensweb.com/drcc.htm Yahoo! Groups Links
Re: [digitalradio] FIR Filters
A third party DFT implementation should prove that the coefficients aren't completely incorrect. Beyond that, wouldn't it be more useful to feed the filter design parameters into another implementation of the Remez exchange algorithm and compare the results? 73, John KD6OZH - Original Message - From: Simon Brown To: digitalradio@yahoogroups.com ; [EMAIL PROTECTED] Cc: digitalradio@yahoogroups.com Sent: Monday, January 21, 2008 17:58 UTC Subject: Re: [digitalradio] FIR Filters Hi, This is not a problem, but I would like to feed my data into a 3-rd party program to prove my design, that's all :-) Simon Brown, HB9DRV - Original Message - From: John B. Stephensen Since the filter coefficients are the impulse response, you should be able to do a DFT of the coefficients to get the frequency response.
Re: [digitalradio] FIR Filters
Points taken John, but if I do all the coding then I will not find any errors I think. I'll know soon whether my design is correct - it's really a question of using correct Nyquist adjusted frequencies etc. Simon Brown, HB9DRV - Original Message - From: John B. Stephensen To: digitalradio@yahoogroups.com ; [EMAIL PROTECTED] Cc: digitalradio@yahoogroups.com Sent: Monday, January 21, 2008 7:12 PM Subject: Re: [digitalradio] FIR Filters A third party DFT implementation should prove that the coefficients aren't completely incorrect. Beyond that, wouldn't it be more useful to feed the filter design parameters into another implementation of the Remez exchange algorithm and compare the results? 73, John KD6OZH - Original Message - From: Simon Brown To: digitalradio@yahoogroups.com ; [EMAIL PROTECTED] Cc: digitalradio@yahoogroups.com Sent: Monday, January 21, 2008 17:58 UTC Subject: Re: [digitalradio] FIR Filters Hi, This is not a problem, but I would like to feed my data into a 3-rd party program to prove my design, that's all :-) Simon Brown, HB9DRV - Original Message - From: John B. Stephensen Since the filter coefficients are the impulse response, you should be able to do a DFT of the coefficients to get the frequency response.
Re: [digitalradio] FIR Filters
OK. I have the MDS product (QEDesign 1000) and could compare the coefficients generated if that helps. 73, John KD6OZH - Original Message - From: Simon Brown To: digitalradio@yahoogroups.com Sent: Monday, January 21, 2008 18:21 UTC Subject: Re: [digitalradio] FIR Filters Points taken John, but if I do all the coding then I will not find any errors I think. I'll know soon whether my design is correct - it's really a question of using correct Nyquist adjusted frequencies etc. Simon Brown, HB9DRV - Original Message - From: John B. Stephensen To: digitalradio@yahoogroups.com ; [EMAIL PROTECTED] Cc: digitalradio@yahoogroups.com Sent: Monday, January 21, 2008 7:12 PM Subject: Re: [digitalradio] FIR Filters A third party DFT implementation should prove that the coefficients aren't completely incorrect. Beyond that, wouldn't it be more useful to feed the filter design parameters into another implementation of the Remez exchange algorithm and compare the results? 73, John KD6OZH - Original Message - From: Simon Brown To: digitalradio@yahoogroups.com ; [EMAIL PROTECTED] Cc: digitalradio@yahoogroups.com Sent: Monday, January 21, 2008 17:58 UTC Subject: Re: [digitalradio] FIR Filters Hi, This is not a problem, but I would like to feed my data into a 3-rd party program to prove my design, that's all :-) Simon Brown, HB9DRV - Original Message - From: John B. Stephensen Since the filter coefficients are the impulse response, you should be able to do a DFT of the coefficients to get the frequency response.
Re: [digitalradio] FIR Filters
I think maybe what you want is MATLAB. It has its own Parks-McClellan designer, firpm. It also has an estimator for required order, given band edges and desired amplitudes. You can then trivially plot the h(n), error, etc from within Matlab. I don't know if the free clones of Matlab (Scllab, and to a lesser extent Octave) have the libraries you would want but it is worth a look. Leigh/WA5ZNU On Mon, 21 Jan 2008 12:46 am, Simon Brown wrote: Hi Sergio, I am able to design using Parks-McClellan and to be honest I think my UI is better than ScopeFIR's. What I would like (but not essential) is the ability to take my filter coefficients and validate them with another program. I don't see this in ScopeFIR, although I could possible write my own code to do what I want I need to validate my filters with a program not created by my own fair hands :-) With a filter covering 0 to 4,000Hz I simply feed a signal in, see what I get out and do some sums... Simon Brown, HB9DRV - Original Message - From: [EMAIL PROTECTED] I have tried ScopeFIR so far. Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked DRCC contest info : http://www.obriensweb.com/drcc.htm Yahoo! Groups Links
Re: [digitalradio] FIR Filters
An example of the filter design (ignore the numbers in the toolbar please): http://gallery.ham-radio.ch/main.php?g2_itemId=14198g2_imageViewsIndex=2 Simon Brown, HB9DRV - Original Message - From: Simon Brown I have written my own code to design FIR filters using Parks-McClellan. Are there any programs I can use to test the filter by supplying my table of coefficients?
Re: [digitalradio] FIR Filters
Simon, Check this out: http://www.dspguru.com/sw/tools/filtdsn.htm I have tried ScopeFIR so far. Regards, Sergio, EA3DU Mensaje original De: [EMAIL PROTECTED] Recibido: 20/01/2008 23:15 Para: Asunto: [digitalradio] FIR Filters I have written my own code to design FIR filters using Parks- McClellan. Are there any programs I can use to test the filter by supplying my table of coefficients? This is part of some SSTV code, I wrote the software as I couldn't find what I needed out there on the web. Simon Brown, HB9DRV
