Re: LF: Spectrum Lab Filtering...

[Markus Vester <markusvester@aol.com>]

Hi there,

 

I think Wolf's idea is to lock to 1 pps pulses from the GPS, and use the NMEA data to uniquely identify the second of each pulse. This will allow SpecLab to brigde data outages or sound buffer overflows on receive.

 

I do not know if that technique could be used to stabilize sound output for transmitting as well. One would probably have to monitor the output, and then apply phase corrections if necessary.

 

Best 73,

Markus  

-----Ursprüngliche Mitteilung-----
Von: Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>
An: rsgb_lf_group@blacksheep.org
Verschickt: Di., 10. Mai. 2011, 13:15
Thema: Re: LF: Spectrum Lab Filtering...

Hi Alan, 
 
I'm not an expert of such communication formats but i totally trust the skills of Wolf. Before some years i think most people would have said that it's not possible to use MSK transmitter signal as a "quasi perfect reference signal" and now we have this function included in SpecLab, which allows us to display and generate DFCW-60000 and maybe slower... 
 
Let's see what he will perform magic soon! :-) 
 
73, Stefan/DK7FC 
 
Am 10.05.2011 12:22, schrieb Alan Melia: 
> Hi Stefan if you are thinking of NMEA for timing I think you will find it 
> inadequate Andy did some work on this many years back and I believe he found 
> there was an inconsistent delay in the NMEA strings ...... differences of up 
> to a second I believe. One the Oncore boards from Motorola he found the 
> Motorola proprietry comms was much better. NMEA is only intended for 
> transmission of data between instruments in relatively slow moving vessels, 
> so that sort of uncertainty is not really an issue. 
> 
> Alan 
> G3NYK 
> 
> ----- Original Message ----- 
> From: "Stefan Schäfer"<Stefan.Schaefer@iup.uni-heidelberg.de> 
> To:<rsgb_lf_group@blacksheep.org> 
> Sent: Tuesday, May 10, 2011 10:27 AM 
> Subject: Re: LF: Spectrum Lab Filtering... 
> 
> 
> >> Wolf, 
>> 
>> Thanks for the excellent service, once again! 
>> I just downloaded the new version on the LF PC and will install it 
>> separately. I'll test it with Markus in CW and will give you a feedback 
>> here. 
>> 
>> BTW what about the NMEA GPS communication? Does it already work 
>> sufficiently? I would have problems to run my grabber PC at 10 SL 
>> instances in stereo mode but when beeing /p TXing, it would be a great 
>> improvement!!! 
>> 
>> 73, Stefan/DK7FC 
>> 
>> 
>> Am 09.05.2011 22:39, schrieb wolf_dl4yhf: 
>> >>> Hello Scott and Stefan, 
>>> 
>>> I have just uploaded yet another 'beta' of spectrum lab (V2.76 b24) to 
>>> this site: 
>>> 
>>> http://dl4yhf.ssl7.com/speclab/install_speclab_beta.zip 
>>> 
>>> The automatic multi-notch filter now has up to three adjustable 
>>> frequency ranges. If none of the ranges is selected, it operates on 
>>> the entire spectrum (in the passband). The active ranges, if any, are 
>>> displayed by red horizontal lines in the filter control window (the 
>>> graphic part). 
>>> 
>>> BEWARE: Keep a copy of your old version ! I made so many changes in 
>>> the code (mostly for the GPS-sync) that there is the risk that older, 
>>> less frequently used (and rarely tested) functions don't work with 
>>> this version. If so, please let me know. 
>>> 
>>> All the best, 
>>> Wolf . 
>>> 
>>> >> >