I don't know the advertized numbers, but Mr. Nyquist aside, there is a reason that two independent experts with panadapter displays (Joe Subich W4TV and Larry Phipps K8LP of LP-Pan fame) state that a soundcard with a 48 kHz rate will produce a 96 kHz span on the pan display.
I do not doubt Nyquist, but I think the treatment of the numbers are a bit different (factor of 2) Could it be due to the two channels? I really don't know the answers and do not have the energy to investigate such things anymore, I just choose to trust the experts who deal with this I/Q stuff on a daily basis. I guess my scientific curiosity has declined with advancing years - it is no longer enjoyable to argue on the basis of observations vs. theory to sort out the differences - that was "fun mind games" many years ago. but today it is no longer a challenge. 73, Don W3FPR On 8/19/2012 5:45 PM, WB4JFI wrote: > Mr Nyquist would be happily surprised at that. With I&Q samples at 48kS/s > each, you get a maximum of 48kHz, or one-half the total bandwidth. Not > 48k+48k. > > So, with a 48k sample rate, you will get plus and minus 24k from center. > > Sent from tfox iPad > > On Aug 19, 2012, at 4:33 PM, "Joe Subich, W4TV" <li...@subich.com> wrote: > >>> The sound card's maximum sampling rate will determine how wide your >>> panadapter display can be (in kHz); for example, a sound card capable >>> of sampling at 48 kHz can display slightly less than 48 kHz of >>> spectrum. If you want a wider display, you will have to ensure that >>> your sound card can sample at higher rates. >> A sound card capable of 48 KHz sample rate can display slightly less >> than 96 KHz. With I/Q inputs and 48 KHz sampling you get +/- 48 KHz. >> >> 73, >> >> ... Joe, W4TV >> >> On 8/19/2012 4:20 PM, Richard Ferch wrote: >>> Jeff, >>> >>> In addition to the cable, you will also need to be sure that your >>> laptop's sound card accepts stereo input. Panadapter software requires >>> stereo input (I and Q channels). Some laptop input jacks will only >>> accept mono signals, even though the laptop's sound card itself is >>> stereo. My newest laptop, for example, has a TRRS jack for the sound >>> card with a single input line, two stereo output lines, and ground. >>> I have no way to get stereo input into this sound card. An older laptop >>> I have has separate input and output jacks, but while the output jack is >>> stereo, the input jack is mono. If your laptop is like either of these, >>> your only recourse may be to get an external USB sound card with stereo >>> inputs. >>> >>> The sound card's maximum sampling rate will determine how wide your >>> panadapter display can be (in kHz); for example, a sound card capable of >>> sampling at 48 kHz can display slightly less than 48 kHz of spectrum. If >>> you want a wider display, you will have to ensure that your sound card >>> can sample at higher rates. >>> >>> Note that if you need to use an external (e.g. USB) sound card, it may >>> or may not have 3.5mm inputs. For example, I have one with dual RCA >>> phono jacks for its line inputs. With one of these cards, you would need >>> to go from 2.5mm stereo for the KX3's RX I/Q jack to two separate RCA >>> phono plugs for the sound card's input. >>> >>> I don't know whether Radio Shack has the specific cable you would need, >>> but I am sure that they have cables and adapters that could be combined >>> to achieve the desired result. >>> >>> 73, >>> Rich VE3KI >>> >>> >>> WW6L wrote: >>> >>>> Per the manual Iit looks like I would need one of these >>>> >>>> A cable with a 2.5 mm (3/32") plug on one end and >>>> a plug that matches your sound card input on the >>>> other end (typically 3.5 mm [1/8"] stereo) is >>>> required. >>>> >>>> If I want to see a panadapter display on my laptop. >>>> >>>> Where do I get it? >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
