k3/psk on laptop
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Hello all,
thanks for all the replys on the k3 and getting the digital modes to work on a laptop. Found the problem. The laptop was the culprit. Had a speaker mic in the darn thing and it was picking up everything when it was connected to the k3. So changed pc's and all is fine. Worked several stations and received great reports. So all set for field day. Thanks again... Don...w2xb sending again to correct the mice to mic.. hi hi.. |
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Don,
If you plan on a bit more digital work I strongly suggest an external USB or Firewire soundcard. Laptops often have a rotten soundcard, an external card can be amazing. Laptop soundcards are OK for Beep and Ding but for digital mode work they really can be the limiting factor. The K3 has a stonking receiver, it's a shame to cripple it with a laptop soundcard. Simon Brown, HB9DRV -------------------------------------------------- From: "Blachura" <[hidden email]> > thanks for all the replys on the k3 and getting the digital modes to work > on > a laptop. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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> If you plan on a bit more digital work I strongly suggest an > external USB or Firewire soundcard. Laptops often have a rotten > soundcard, an external card can be amazing. I hate to disagree with Simon but I do want to answer the old wives' tale about internal sound cards and laptops ... The issue with internal soundcards - both desktop and laptop is much more one of sensitivity than internal noise. Many amateur transceivers have severely limited audio levels from their "line level" outputs - in some cases it can be as little as 50 mV (-25 dBu) at 10k Ohms. This is generally insufficient when driving the "600 Ohm" inputs of most soundcards. The problem with low input levels is that many inexpensive laptop and internal sound systems may have noise floors as high as -30 to -40 dBu due to poor bypassing and grounding of signals within the computer. If such a soundcard is used with low drive and poor connections that result in external bum/buzz, the results will be poor. Fortunately, the K3 has plenty of drive and due to its ability to produce more than 1 volt RMS output is more than capable of obtaining excellent results with even a very noisy soundcard. One only need adjust the K3's Line Out level until the "no signal" noise from the K3 raises the noise floor as seen on a spectrum (not waterfall) display by 6 - 10 dB. This will provide nearly 40 dB of dynamic range from even a "noisy" soundcard system. The situation is far different with one of the radios that provides only 50 to 100 mV. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Simon > Brown (HB9DRV) > Sent: Tuesday, June 10, 2008 1:10 PM > To: [hidden email] > Subject: Re: [Elecraft] k3/psk on laptop > > > Don, > > If you plan on a bit more digital work I strongly suggest an > external USB or > Firewire soundcard. Laptops often have a rotten soundcard, an > external card > can be amazing. Laptop soundcards are OK for Beep and Ding > but for digital > mode work they really can be the limiting factor. > > The K3 has a stonking receiver, it's a shame to cripple it > with a laptop > soundcard. > > Simon Brown, HB9DRV > > -------------------------------------------------- > From: "Blachura" <[hidden email]> > > > thanks for all the replys on the k3 and getting the digital > modes to work > > on > > a laptop. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Simon (HB9DRV)
> If you plan on a bit more digital work I strongly suggest an
> external USB or Firewire soundcard. Laptops often have a > rotten soundcard, an external card can be amazing. Laptop > soundcards are OK for Beep and Ding but for digital mode work > they really can be the limiting factor. > > The K3 has a stonking receiver, it's a shame to cripple it > with a laptop soundcard. This has not been my experience with RTTY and PSK31 on two K3s for nearly a year now. I've only used the internal sound card on laptops and old desktops with no degradation in performance for all my digital operations. Same for the Icom 756ProII and ProIII as well as the TS950S. This advice comes up on the RTTY reflector from time to time (get a high performance sound card for the digital modes) and there is always a group of relies refuting that advice. I'm not sure what the reason(s) are for disparity on this issue. What do you think the "limiting factor" is? 73, Ed - W0YK/P49X _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Limiting factors - well first you should try a side-by-side comparison of
the average internal laptop soundcard and a high-end solution. With poor soundcards you get: * Reduced dynamic range, (weak signals will be lost) * Intermodulation. You are limiting a very good RX by using a poor soundcard. Good soundcards will meet the K3's RX dynamic range spec more-or-less and deliver a faithful signal to your software. Until you try good, bad and ugly side-by-side you don't know what you are missing. Also - how do you know that you have not suffered degraded performance unless you compare two cards? Using old laptops / soundcards with the K3 is like using a Ferrari 360 with $30 tires. Simon Brown, HB9DRV -------------------------------------------------- From: "Ed Muns" <[hidden email]> > > This has not been my experience with RTTY and PSK31 on two K3s for nearly > a > year now. I've only used the internal sound card on laptops and old > desktops with no degradation in performance for all my digital operations. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Bit more (Plug)
If you're a keen digital modes guy reward yourself and your K3 with a quality product such as USInterface.com Navigator (I have one) or a product from Microham http://www.microham-usa.com/index.html . This is not snake oil, it really makes sense. And clears up lots of cables from the installation. FWIW I use a USInterface Navigator with my K3 and TS-2000, a Edirol FA-66 with my TS-480SAT. Simon Brown, HB9DRV -------------------------------------------------- From: "Simon Brown (HB9DRV)" <[hidden email]> > Limiting factors - well first you should try a side-by-side comparison of > the average internal laptop soundcard and a high-end solution. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Joe Subich, W4TV-3
On Tue, 10 Jun 2008 22:51:02 -0400, Joe Subich, W4TV wrote:
>I hate to disagree with Simon but I do want to answer the old >wives' tale about internal sound cards and laptops ... I agree, Joe, but do so on the basis of far less information than you and Simon, both of whose work I have a great deal of respect for. Sound cards are wildly variable in their quality and characteristics, and virtually all have pin 1 problems. But if you understand how audio level matching works and do the bonding I recommend to eliminate the hum and buzz voltages that exist between equipment that you're interconnecting, most computer sound cars, laptop or otherwise, will work very well. My piece on interfacing is http://audiosystemsgroup.com/HamInterfacing.pdf It is a Power Point for a tutorial I did for a local ham club. The tutorial also exists as text -- it's in Chapter 7 of the RFI tutorial -- Solving Problems in the Shack. Both of these pdfs are written to help hams UNDERSTAND the issues, and provide simple step by step solutions. http://audiosystemsgroup.com/RFI-Ham.pdf is the tutorial. BTW -- my limited sample of laptops over the past 10 years has been almost entirely with Thinkpads, specifically T20-series and T40-series. I bought them new and paid big bucks, but they are now available as used, off-lease units with a legal version of Windows at very modest cost. The T20 and T30 series have a COM port. Later ones do not. Another BTW -- I am told that most laptop mfrs farm out their sound cards to a third party mfr, and they're a commodity. That adds to the wide variation. 73, Jim Brown K9YC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Ed Muns, W0YK
On Wed, 11 Jun 2008 06:29:58 -0700, Ed Muns wrote:
>What do you think the "limiting factor" is? I suspect that much of it is poor level matching. One thing I can measure with a great deal of accuracy is the audio distortion at the output of a sound card. This is quite important for narrowband modes like PSK, because intermod is another signal that interferes with others on the band! Several years ago, I measured the distortion at the output of my laptop sound card. It was 30 dB down from the carrier at maximum output, but 40 dB down from the carrier if I reduced output the level by 6 dB. That is, my signal was 10 dB cleaner simply by running the sound card 6 dB down from max output! More distortion will be created if the audio input of the radio is overdriven, AND if the RF stage is overdriven. In both cases, reasonable care with level matching solves the problem. As Simon and Joe have noted, noise and distortion in the sound card can degrade decoding, but again, proper level matching can improve that situation a LOT. Good operating practice for audio systems is to maximize the output of the driving stage and reduce the input gain of the receiving stage. That is, the output of the radio should be set so that it is operating just below the level where its distortion begins to rise, and the input gain of the computer should be turned down so that it is not overloaded. Sometimes, especially if the computer has only a mic input, a simple resistive voltage divider (pad) is needed between the radio and the computer. That's two resistors, one in series, another in parallel with the input. Guidelines for choosing values are in the tutorials I cited in a previous post. In summary, the noise and distortion problems Simon has cited can usually be solved, and can nearly always be greatly improved, simply by proper level matching. Of course, that won't be true if the sound card is junk. :) 73, Jim Brown K9YC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Jim Brown-10
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From: "Jim Brown" <[hidden email]> > > Another BTW -- I am told that most laptop mfrs farm out their > sound cards to a third party mfr, and they're a commodity. That > adds to the wide variation. > My experience is with Dell laptops and the bog-standard sound chips on older PC's. Some decent new PC's have good sound but another reason for an external soundcard is to ensure no interference from the CPU / mothercard / other innards of the PC. Also it is good to have a soundcard dedicated to the digital modes leaving the other soundcard for Windows sounds and stuff. This reason alone should make you grab a second soundcard. Simon HB9DRV _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Jim Brown-10
Jim, > I agree, Joe, but do so on the basis of far less information than > you and Simon, both of whose work I have a great deal of respect > for. Sound cards are wildly variable in their quality and > characteristics, and virtually all have pin 1 problems. But if you > understand how audio level matching works and do the bonding I > recommend to eliminate the hum and buzz voltages that exist > between equipment that you're interconnecting, most computer sound > cars, laptop or otherwise, will work very well. While there are certainly "pin 1" problems contribute to the problem, the real issue is the high level of internal circuit noise on the motherboards of many laptops and even desktops. I have measured noise floors in the area of -60 dBu on many occasions with NOTHING connected to the soundcard inputs. When that is coupled with transceivers from the "big three" that have line level outputs 20 dB below the 1V RMS the computer sound cards are expecting, the "system" dynamic range is less than 40 dB! Consider that the audio level at the "line" output of many transceivers is only -50 dBu with an antenna connected listening to a "quiet" band and you can see how difficult the situation becomes. On the other hand, if one has a "good" sound system - the Audigy 2ZX in one of my test desktops has a noise floor around -105 dBu and the soundcard in my HP laptop is around -85 dBu the situation is considerably different. Still, external sound and control interfaces (shameless plug - like microHAM DigiKeyer or microKEYER II) make a lot of sense just for one reason - if they contain a very low noise preamp (like the microHAM units) they will the 100mV signal (AGC limit) from the average transceiver and bring it UP to 1 V RMS which improves system dynamic range by 20 dB and makes operation with signals all the way down to the received noise level much more reliable. > Another BTW -- I am told that most laptop mfrs farm out their > sound cards to a third party mfr, and they're a commodity. That > adds to the wide variation. A lot of the laptop manufacturers farm out the design and fabrication of their motherboards to "design/build" shops in the far east - a trend also extends to consumer desktop systems. Most of the design/build shops do not pay attention to the on board noise levels as long as the external/radiated levels are within limits of Part 15 or the EU equivalent. BTW, to answer Ed's question ... even a limited dynamic range is generally satisfactory for "narrow bandwidth" operation. If one is doing RTTY or PKS31 with a narrow (300 - 500 Hz) filter, dynamic range is not a concern as even the weakest signal, as long as it is above the receiver noise floor, will be strong enough for the soundcard/software to demodulate. Finally, from an operational point of view you want to separate the radio from Windows' "beeps and boops." If you use software that announces DX stations, run an e-mail program on the ham computer or play video games on the same machine as you use for RTTY/PSK the chance of other noises getting on the air is much reduced by leaving the "other stuff" on the Windows default sound card and running the digital mode applications and voice keyers (contest loggers) on a dedicated soundcard. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Jim Brown > Sent: Wednesday, June 11, 2008 11:43 AM > To: [hidden email] > Subject: RE: [Elecraft] k3/psk on laptop > > > On Tue, 10 Jun 2008 22:51:02 -0400, Joe Subich, W4TV wrote: > > >I hate to disagree with Simon but I do want to answer the old > >wives' tale about internal sound cards and laptops ... > > I agree, Joe, but do so on the basis of far less information than > you and Simon, both of whose work I have a great deal of respect > for. Sound cards are wildly variable in their quality and > characteristics, and virtually all have pin 1 problems. But if you > understand how audio level matching works and do the bonding I > recommend to eliminate the hum and buzz voltages that exist > between equipment that you're interconnecting, most computer sound > cars, laptop or otherwise, will work very well. > > My piece on interfacing is > > http://audiosystemsgroup.com/HamInterfacing.pdf > > It is a Power Point for a tutorial I did for a local ham club. The > tutorial also exists as text -- it's in Chapter 7 of the RFI > tutorial -- Solving Problems in the Shack. Both of these pdfs are > written to help hams UNDERSTAND the issues, and provide simple > step by step solutions. > > http://audiosystemsgroup.com/RFI-Ham.pdf is the tutorial. > > BTW -- my limited sample of laptops over the past 10 years has > been almost entirely with Thinkpads, specifically T20-series and > T40-series. I bought them new and paid big bucks, but they are now > available as used, off-lease units with a legal version of Windows > at very modest cost. The T20 and T30 series have a COM port. Later > ones do not. > > Another BTW -- I am told that most laptop mfrs farm out their > sound cards to a third party mfr, and they're a commodity. That > adds to the wide variation. > > 73, > > Jim Brown K9YC > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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On Wed, 11 Jun 2008 13:34:21 -0400, Joe Subich, W4TV wrote:
>BTW, to answer Ed's question ... even a limited dynamic range >is generally satisfactory for "narrow bandwidth" operation. You're exactly right, Joe, and this is quite important. Signal to noise measurements are broadband, but RTTY and PSK decoders are looking VERY narrowband. The noise in the narrow bandwidth of good PSK and RTTY decoders is a tiny fraction of the measured broadband noise, but the signal level can be the full output of the RX. It's the same sort of advantage that an RX with good IF filtering enjoys. While I haven't done studies on the subject, I'd bet that amplitude distortion and phase distortion are of much greater signifcance. And phase distortion mostly occurs in the IF of the radios as a byproduct of the filters, so I would expect radios with better filters to be better RTTY and PSK performers. These factors certainly ARE a major contributor to speech intelligibility, which is why the K2 is not wonderful in narrow SSB modes -- the amplitude and phase response of the stagger-tuned filters looks like the cut-through of a mountain range! Ed -- do you have any anecodotal or other experience on that? 73, Jim Brown K9YC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Simon (HB9DRV)
> Limiting factors - well first you should try a side-by-side
> comparison of the average internal laptop soundcard and a > high-end solution. I have (US Navigator) and there was no difference. Maybe the internal sound cards I've used are "good enough" compared to ones you've seen. Also, my only experience is with the RTTY (200-300 Hz filtering) and a limited amount of PSK31. 73, Ed - W0YK _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Maybe you had a good card - but I find that with a good external card I just
don't need any filtering as the high dynamic range of the soundcard + K3 (or TS-480SAT) makes it unnecessary. Simon Brown, HB9DRV -------------------------------------------------- From: "Ed Muns" <[hidden email]> >> Limiting factors - well first you should try a side-by-side >> comparison of the average internal laptop soundcard and a >> high-end solution. > > I have (US Navigator) and there was no difference. Maybe the internal > sound > cards I've used are "good enough" compared to ones you've seen. Also, my > only experience is with the RTTY (200-300 Hz filtering) and a limited > amount > of PSK31. > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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> Maybe you had a good card - but I find that with a good
> external card I just don't need any filtering as the high > dynamic range of the soundcard + K3 (or > TS-480SAT) makes it unnecessary. That doesn't work as well in large RTTY pileups. I use tight filters, even 200 Hz at times. 73, Ed - W0YK _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Simon (HB9DRV)
"I find that with a good external card I just don't need any filtering"
Huh? What about the AGC? Watching the waterfall you can easily see weak signals disappear when a strong one comes pops up within your bandpass. This is normal and no amount of dynamic range has any bearing on it. Sharp IF filters are the key to operating digital modes. Steve Ellington [hidden email] ----- Original Message ----- From: "Simon Brown (HB9DRV)" <[hidden email]> To: <[hidden email]> Cc: <[hidden email]> Sent: Wednesday, June 11, 2008 2:46 PM Subject: Re: [Elecraft] k3/psk on laptop > Maybe you had a good card - but I find that with a good external card I > just > don't need any filtering as the high dynamic range of the soundcard + K3 > (or > TS-480SAT) makes it unnecessary. > > Simon Brown, HB9DRV > > -------------------------------------------------- > From: "Ed Muns" <[hidden email]> > >>> Limiting factors - well first you should try a side-by-side >>> comparison of the average internal laptop soundcard and a >>> high-end solution. >> >> I have (US Navigator) and there was no difference. Maybe the internal >> sound >> cards I've used are "good enough" compared to ones you've seen. Also, my >> only experience is with the RTTY (200-300 Hz filtering) and a limited >> amount >> of PSK31. >> > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 270.2.0/1497 - Release Date: 6/11/2008 8:32 AM _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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