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USB sound dongle

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hhoyt

USB sound dongle

Hi,

I have been following the fun on this reflector while awaiting my KX3
(next Friday!). I am very interested in using the I&Q outs to interface
with my laptop, and as many have noted, you need a good, compatible
sound device to have a usable panadapter display. Does any one have
experience with a 192k sampling USB sound dongle for their laptop?

TIA!

Howie

Howard Hoyt - WA4PSC
CE - WXYC-FM 89.3
UNC Chapel Hill, NC
www.wxyc.org
1st on the internet
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Joe Subich, W4TV-4

Re: USB sound dongle

> Does any one have experience with a 192k sampling USB sound dongle
> for their laptop?

You're not likely to find 192 KHz sampling in anything less than
something like the e-MU 0202/0204 USB devices. The commodity "dongles"
are designed for USB headset or basic audio I/O use and are generally
built with TI (Burr-Brown) or cMedia single chip USB CODECs that use
the USB Audio CLASS device specification. I do not believe the Windows
USB AUDIO CLASS driver (built into the operating system) will support
sample rates above 48 KHz - at least I have not seen that option.

73,

... Joe, W4TV

On 8/20/2012 12:37 AM, Howard Hoyt wrote:

> Hi,
>
> I have been following the fun on this reflector while awaiting my KX3
> (next Friday!). I am very interested in using the I&Q outs to interface
> with my laptop, and as many have noted, you need a good, compatible
> sound device to have a usable panadapter display. Does any one have
> experience with a 192k sampling USB sound dongle for their laptop?
>
> TIA!
>
> Howie
>
> Howard Hoyt - WA4PSC
> CE - WXYC-FM 89.3
> UNC Chapel Hill, NC
> www.wxyc.org
> 1st on the internet
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Barry K3NDM

Re: USB sound dongle

In reply to this post by hhoyt

Howie,
The dongles I have seen are not spectacular. They are about on par
with your average stereo laptop soundcard, OK but not great. I use a
E-MU0202 from Creative Labs. This card is a 24 bit card that can sample
beyond what Elecraft recommends. However, this card is not current; I
think the 0404 replaces it. Someone can address this for you. You really
do want a 24 bit card and not 16 bit one. The other thing is that that
card should have low internal noise; the high end Creative Labs card
meet this as does several others.

There are a number of software packages around that you can use. I
use NaP3 because it can control the KX3 and allows me to use VAC so that
I can pipe the output to FLDIGI for reading the digial modes. I have
essentially a full up computer controlled SDR that I can take out for
Field Day and operate portable with knobs and a battery. It's the craziest!.

I think, once you have it all lashed up, you will really have some
fun. Good luck and do use a good card with ASIO drivers for best
performance.

73,
Barry
K3NDM

On 8/20/2012 12:37 AM, Howard Hoyt wrote:

Joe Subich, W4TV-4

Re: USB sound dongle

> However, this card is not current; I think the 0404 replaces it.
> Someone can address this for you.

The current version is eMU 0204 - approximately $125 at places
like B&H Photo Video.

> You really do want a 24 bit card and not 16 bit one.

Unless you need the high sample frequency for wide panadapter service,
any well designed 16 bit/48 KHz USB sound device will provide all the
performance you need at less than 1/4 the price of something like the
eMU 0204.

> The other thing is that that card should have low internal noise;

This is *the most important* determinant of performance. Internal
noise dramatically reduces the effective dynamic range of the sound
card.

73,

... Joe, W4TV

On 8/20/2012 4:40 PM, Barry LaZar wrote:

> Howie,
> The dongles I have seen are not spectacular. They are about on par
> with your average stereo laptop soundcard, OK but not great. I use a
> E-MU0202 from Creative Labs. This card is a 24 bit card that can sample
> beyond what Elecraft recommends. However, this card is not current; I
> think the 0404 replaces it. Someone can address this for you. You really
> do want a 24 bit card and not 16 bit one. The other thing is that that
> card should have low internal noise; the high end Creative Labs card
> meet this as does several others.
>
> There are a number of software packages around that you can use. I
> use NaP3 because it can control the KX3 and allows me to use VAC so that
> I can pipe the output to FLDIGI for reading the digial modes. I have
> essentially a full up computer controlled SDR that I can take out for
> Field Day and operate portable with knobs and a battery. It's the craziest!.
>
> I think, once you have it all lashed up, you will really have some
> fun. Good luck and do use a good card with ASIO drivers for best
> performance.
>
> 73,
> Barry
> K3NDM
>
>
> On 8/20/2012 12:37 AM, Howard Hoyt wrote:
>> Hi,
>>
>> I have been following the fun on this reflector while awaiting my KX3
>> (next Friday!). I am very interested in using the I&Q outs to interface
>> with my laptop, and as many have noted, you need a good, compatible
>> sound device to have a usable panadapter display. Does any one have
>> experience with a 192k sampling USB sound dongle for their laptop?
>>
>> TIA!
>>
>> Howie
>>
>> Howard Hoyt - WA4PSC
>> CE - WXYC-FM 89.3
>> UNC Chapel Hill, NC
>> www.wxyc.org
>> 1st on the internet
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> 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:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
>

Tim Herrick

Re: USB sound dongle

Unfortunately the 0204 does not work very well with Win 7. The only drivers they have come out with are beta and they have never
finished them. It cuts out and has to be restarted. Also the audio is very poor for the 96/192 modes in W7. Mine works fine with XP
though but wouldn't work very well on my W7 box. I have seen a lot of complaints by the audio people about the lack of support.
Also, I was lucky to find one but have had a hard time trying to find a replacement. It seems the 0404 is the replacement.

73,
Tim Herrick, KQ8M
Charter Member North Coast Contesters
[hidden email]

AR-Cluster V6 kq8m.no-ip.org
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-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of Joe Subich, W4TV
Sent: Tuesday, August 21, 2012 10:14 AM
To: [hidden email]
Subject: Re: [Elecraft] USB sound dongle

> However, this card is not current; I think the 0404 replaces it.
> Someone can address this for you.

The current version is eMU 0204 - approximately $125 at places
like B&H Photo Video.

> You really do want a 24 bit card and not 16 bit one.

Unless you need the high sample frequency for wide panadapter service,
any well designed 16 bit/48 KHz USB sound device will provide all the
performance you need at less than 1/4 the price of something like the
eMU 0204.

> The other thing is that that card should have low internal noise;

This is *the most important* determinant of performance. Internal
noise dramatically reduces the effective dynamic range of the sound
card.

73,

... Joe, W4TV

On 8/20/2012 4:40 PM, Barry LaZar wrote:

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Barry K3NDM

Re: USB sound dongle

In reply to this post by Joe Subich, W4TV-4

Joe,
I agree with your comment on internal noise. However, 24 bits of
quantization will get you a better dynamic range. But, It becomes an
interesting point when the effects of receiver AGC gets into the
discussion on this point. Someone in a much earlier post said that the
receiver's AGC would keep things within bounds for a 16 bit card; he may
be correct. But, if you run without AGC on the receiver and use AGC
developed by the SDR software, having those extra bits will make a
difference, particularly during noisy periods or contests.

The issue is really when will all those bits go to a logic 1. With
16 bits, it will be ~96 db where db=20log V2/V1. I know this is not what
most perceive, but it's true the A/D convertor is a voltage sensitive
and not a power sensitive device. There are some other interesting
subtleties like how much dynamic range do you really need, etc. Since I
haven't had my first cup of coffee yet, I think I would not like to get
in to those at this time.

73,
Barry
K3NDM

On 8/21/2012 10:13 AM, Joe Subich, W4TV wrote:

>> However, this card is not current; I think the 0404 replaces it.
>> Someone can address this for you.
> The current version is eMU 0204 - approximately $125 at places
> like B&H Photo Video.
>
>> You really do want a 24 bit card and not 16 bit one.
> Unless you need the high sample frequency for wide panadapter service,
> any well designed 16 bit/48 KHz USB sound device will provide all the
> performance you need at less than 1/4 the price of something like the
> eMU 0204.
>
> > The other thing is that that card should have low internal noise;
>
> This is *the most important* determinant of performance. Internal
> noise dramatically reduces the effective dynamic range of the sound
> card.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 8/20/2012 4:40 PM, Barry LaZar wrote:
>> Howie,
>> The dongles I have seen are not spectacular. They are about on par
>> with your average stereo laptop soundcard, OK but not great. I use a
>> E-MU0202 from Creative Labs. This card is a 24 bit card that can sample
>> beyond what Elecraft recommends. However, this card is not current; I
>> think the 0404 replaces it. Someone can address this for you. You really
>> do want a 24 bit card and not 16 bit one. The other thing is that that
>> card should have low internal noise; the high end Creative Labs card
>> meet this as does several others.
>>
>> There are a number of software packages around that you can use. I
>> use NaP3 because it can control the KX3 and allows me to use VAC so that
>> I can pipe the output to FLDIGI for reading the digial modes. I have
>> essentially a full up computer controlled SDR that I can take out for
>> Field Day and operate portable with knobs and a battery. It's the craziest!.
>>
>> I think, once you have it all lashed up, you will really have some
>> fun. Good luck and do use a good card with ASIO drivers for best
>> performance.
>>
>> 73,
>> Barry
>> K3NDM
>>
>>
>> On 8/20/2012 12:37 AM, Howard Hoyt wrote:
>>> Hi,
>>>
>>> I have been following the fun on this reflector while awaiting my KX3
>>> (next Friday!). I am very interested in using the I&Q outs to interface
>>> with my laptop, and as many have noted, you need a good, compatible
>>> sound device to have a usable panadapter display. Does any one have
>>> experience with a 192k sampling USB sound dongle for their laptop?
>>>
>>> TIA!
>>>
>>> Howie
>>>
>>> Howard Hoyt - WA4PSC
>>> CE - WXYC-FM 89.3
>>> UNC Chapel Hill, NC
>>> www.wxyc.org
>>> 1st on the internet
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> 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:[hidden email]
>>
>> 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:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Jim Brown-10

Re: USB sound dongle

In reply to this post by Tim Herrick

On 8/21/2012 7:26 AM, KQ8M wrote:
> Unfortunately the 0204 does not work very well with Win 7.

EMU is on by $&%*@ list because of their conscious decision to NOT
support discontinued products. When I went looking for a driver for my
0202, I found that EMU had removed it from their website ON PURPOSE.

I managed to find a couple of drivers on third party websites, one of
which wrecked a XP Pro system so badly (it wouldn't boot!) that I had
to do a complete restore. I found a driver that worked on N8LP's website.

I will repeat recommendations I have posted here several times for good
low cost USB audio interfaces. These are plain vanilla 48 kHz units,
intended for semi-pro home studio audio playback and recording, and for
DJs. One is the lowest cost Numark unit, sold by B&H Photo for about
$30. Another is the lowest cost Tascam, sold by B&H for about $70. Both
are free of Pin One Problems, work with generic Windoze drivers, have
stereo RIAA Phono Inputs, and Line Level inputs and outputs, and the
outputs are adjustable. The Tascam also has a mono mic input, a mono
guitar input, and an input gain control. It is the one I like best. Both
work equally well decoding and encoding digital signals.

Someone recommended a cute little Byterunner unit that is much smaller,
and sells for about $35. I bought one and tried it. While it works as
well as the others for encoding and decoding, it's quite cheaply made
and I found the connections to be flaky at times. It does NOT work with
generic Windoze drivers, and comes with its own on a CDROM.

If I were looking for a USB adapter for spectrum display, I'd poke
around websites for distributors of equipment for home recording studios
and study their specs. Some of the better distributors are Full Compass,
Sweetwater, B&H Photo. Be sure to figure out which version(s) of USB
they support, and which version of USB your computer has. The newer,
slicker stuff will be at least USB 2.0, and sound cards that don't tell
you are probably USB 1.1, which works with USB 2.0 systems. But USB 2.0
sound cards may not work, or work as well, with USB 1.1 computers.

73, Jim K9YC
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Jim Brown-10

Re: USB sound dongle

In reply to this post by Barry K3NDM

On 8/21/2012 7:48 AM, Barry LaZar wrote:
> However, 24 bits of
> quantization will get you a better dynamic range.

Not if the dynamic range of the analog electronics limits it, which is
what Joe has pointed out. Often those extra bits are "advertising bits"
-- they fool those who don't know any better into believing that more
bits is better. Actually, it's far more important to optimize the
signal level that the A/D converter sees. That's why I like the Tascam
USB interface better than the Numark -- it has a much greater range of
gain adjustment and a clip light on the front panel. That allows me to
easily optimize the 90 dB or so of dynamic range that its 16 bits provides.

Besides -- the 90 dB dynamic range provided by a decent 16-bit A/D is
probably more than most hams will ever see at the audio output of their
radios. While the radio itself has much greater dynamic range, the
WORKING dynamic range is limited by noise received by the antenna that
is often 30-50 dB greater than the electrical noise levels inside the
radio.

73, Jim K9YC
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Tony Estep

Re: USB sound dongle

In reply to this post by Barry K3NDM

On Mon, Aug 20, 2012 at 3:40 PM, Barry LaZar <[hidden email]> wrote:

> ....I use NaP3 because it can control the KX3 and allows me to use VAC so
> that
> I can pipe the output ....

===========
Note that to do this you have to have 2 sound cards, one for the I-Q and
one for the digi program. I found this out the dumb way by actually setting
it up to use my internal 192K sound module for both. Surprisingly, it
actually works after a fashion, but of course the digi program is listening
not only to what's coming from the receiver in NaP3 but also to the
wideband I and Q signals, and the NaP3 program is listening not only to I
and Q, but also to its own output. Took a while before I eventually I
realized my mistake.

Tony KT0NY

--
http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352
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Tony Estep

Re: USB sound dongle

In reply to this post by Tim Herrick

On Tue, Aug 21, 2012 at 9:26 AM, KQ8M <[hidden email]> wrote:

> Unfortunately the 0204 does not work very well with Win 7....

===========
That's too bad -- I hadn't heard that. The 0202 works perfectly with
Windows 7, but is long gone and now replaced by the 0404. There are other
makes as well, including M-Audio and Delta. You can find out all about
sound cards for SDRs on the Yahoo Softrock group. There are many test
results posted there.

Tony KT0NY

--
http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352
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Joe Subich, W4TV-4

Re: USB sound dongle

In reply to this post by Jim Brown-10

On 8/21/2012 11:18 AM, Jim Brown wrote:
> On 8/21/2012 7:48 AM, Barry LaZar wrote:
>> However, 24 bits of quantization will get you a better dynamic
>> range.
>
> Not if the dynamic range of the analog electronics limits it, which
> is what Joe has pointed out. Often those extra bits are "advertising
> bits" -- they fool those who don't know any better into believing
> that more bits is better.

There are two issues here -

First most amateurs run their digital software from "line out" or the
demodulated audio from the transceiver. The demodulated audio has
generally been through at least one A to D to A cycle and the noise
floor is simply too high to take advantage of even the theoretical 96
dB dynamic range of a 16 bit sound card.

Now, if one is looking at the "raw" I/Q RF/IF or direct downconversion
audio 24 bits "might" be usable *IF* the noise floor is low enough (a
real *IF* with off the air signals) and any mixers and amplifiers are
really linear through the theoretical 138 dB dynamic range *without* AGC.

None of this addresses the noise floor and dynamic range of any preamp
in the sound card ... it only looks at the theoretical dynamic range
of the analog to digital converter.

Then there is an additional consideration pointed out by Chen in a
private e-mail - properly designed software can achieve dynamic range
(sensitivity) *better than* the A to D converter (that is, it can
"receive into the noise") by applying proper lowpass filtering and
decimation. I know Chen uses decimation even with 16 bit cards in
cocoaModem but it does not appear that any of the Windows centric
digital software does so since many are based on 11025 or 12000 Hz
sample rates and effectively throw away the potential processing gain
by not performing any lowpass filtering in the 44100/48000 to 11025
or 12000 sample rate downconversion.

73,

... Joe, W4TV

On 8/21/2012 11:18 AM, Jim Brown wrote:

> On 8/21/2012 7:48 AM, Barry LaZar wrote:
>> However, 24 bits of
>> quantization will get you a better dynamic range.
>
> Not if the dynamic range of the analog electronics limits it, which is
> what Joe has pointed out. Often those extra bits are "advertising bits"
> -- they fool those who don't know any better into believing that more
> bits is better. Actually, it's far more important to optimize the
> signal level that the A/D converter sees. That's why I like the Tascam
> USB interface better than the Numark -- it has a much greater range of
> gain adjustment and a clip light on the front panel. That allows me to
> easily optimize the 90 dB or so of dynamic range that its 16 bits provides.
>
> Besides -- the 90 dB dynamic range provided by a decent 16-bit A/D is
> probably more than most hams will ever see at the audio output of their
> radios. While the radio itself has much greater dynamic range, the
> WORKING dynamic range is limited by noise received by the antenna that
> is often 30-50 dB greater than the electrical noise levels inside the
> radio.
>
> 73, Jim K9YC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Rick Johnson-2

Re: USB sound dongle

Has anyone ever used a NewQ Gold DSP in conjunction with
digital ops?
I was given one and don't really know if it usable for digital.

73,
Rick W3BI

> Date: Tue, 21 Aug 2012 14:28:10 -0400
> From: [hidden email]
> To: [hidden email]
> Subject: Re: [Elecraft] USB sound dongle
>
>
> On 8/21/2012 11:18 AM, Jim Brown wrote:
> > On 8/21/2012 7:48 AM, Barry LaZar wrote:
> >> However, 24 bits of quantization will get you a better dynamic
> >> range.
> >
> > Not if the dynamic range of the analog electronics limits it, which
> > is what Joe has pointed out. Often those extra bits are "advertising
> > bits" -- they fool those who don't know any better into believing
> > that more bits is better.
>
> There are two issues here -
>
> First most amateurs run their digital software from "line out" or the
> demodulated audio from the transceiver. The demodulated audio has
> generally been through at least one A to D to A cycle and the noise
> floor is simply too high to take advantage of even the theoretical 96
> dB dynamic range of a 16 bit sound card.
>
> Now, if one is looking at the "raw" I/Q RF/IF or direct downconversion
> audio 24 bits "might" be usable *IF* the noise floor is low enough (a
> real *IF* with off the air signals) and any mixers and amplifiers are
> really linear through the theoretical 138 dB dynamic range *without* AGC.
>
> None of this addresses the noise floor and dynamic range of any preamp
> in the sound card ... it only looks at the theoretical dynamic range
> of the analog to digital converter.
>
> Then there is an additional consideration pointed out by Chen in a
> private e-mail - properly designed software can achieve dynamic range
> (sensitivity) *better than* the A to D converter (that is, it can
> "receive into the noise") by applying proper lowpass filtering and
> decimation. I know Chen uses decimation even with 16 bit cards in
> cocoaModem but it does not appear that any of the Windows centric
> digital software does so since many are based on 11025 or 12000 Hz
> sample rates and effectively throw away the potential processing gain
> by not performing any lowpass filtering in the 44100/48000 to 11025
> or 12000 sample rate downconversion.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 8/21/2012 11:18 AM, Jim Brown wrote:
> > On 8/21/2012 7:48 AM, Barry LaZar wrote:
> >> However, 24 bits of
> >> quantization will get you a better dynamic range.
> >
> > Not if the dynamic range of the analog electronics limits it, which is
> > what Joe has pointed out. Often those extra bits are "advertising bits"
> > -- they fool those who don't know any better into believing that more
> > bits is better. Actually, it's far more important to optimize the
> > signal level that the A/D converter sees. That's why I like the Tascam
> > USB interface better than the Numark -- it has a much greater range of
> > gain adjustment and a clip light on the front panel. That allows me to
> > easily optimize the 90 dB or so of dynamic range that its 16 bits provides.
> >
> > Besides -- the 90 dB dynamic range provided by a decent 16-bit A/D is
> > probably more than most hams will ever see at the audio output of their
> > radios. While the radio itself has much greater dynamic range, the
> > WORKING dynamic range is limited by noise received by the antenna that
> > is often 30-50 dB greater than the electrical noise levels inside the
> > radio.
> >
> > 73, Jim K9YC
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > 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:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

Joe Subich, W4TV-4

Re: USB sound dongle

In reply to this post by Barry K3NDM

Barry,

> The issue is really when will all those bits go to a logic 1. With 16
> bits, it will be ~96 db where db=20log V2/V1. I know this is not
> what most perceive, but it's true the A/D convertor is a voltage
> sensitive and not a power sensitive device.

The issue with dynamic range is just as much the ability of all those
bits to go to logic 0. If the receiver has so much noise - whether
atmospheric noise at the antenna, thermal noise in the IF, masking
due to A/D/A conversions in the demodulator, or thermal noise/hum in
the audio output stages, the sound card will never achieve even the
theoretical 96 dB dynamic range for 16 bit A/D.

Add to that, switching noise on the typical USB power line, the lack of
secondary regulation in inexpensive USB sound "dongles", the failure
to provide a separate *regulated* reference for the ADC, failures to
provide *regulated* references for op-amp preamps, lack of attention
to grounding and bypassing, etc. and the noise floor in commodity USB
sound devices (and "inexpensive" amateur products) further limits the
achievable dynamic range.

With external noise sources, it doesn't matter if one has a 16 or 24
bit ADC, the achievable dynamic range will be limited to the area
between *all* of the noise contributors and the maximum voltage
handling capability (typically < 5.0V) of the ADC ... or between
65 and 70 dB in many of the commodity and inexpensive amateur
devices.

73,

... Joe, W4TV

On 8/21/2012 10:48 AM, Barry LaZar wrote:

> Joe,
> I agree with your comment on internal noise. However, 24 bits of
> quantization will get you a better dynamic range. But, It becomes an
> interesting point when the effects of receiver AGC gets into the
> discussion on this point. Someone in a much earlier post said that the
> receiver's AGC would keep things within bounds for a 16 bit card; he may
> be correct. But, if you run without AGC on the receiver and use AGC
> developed by the SDR software, having those extra bits will make a
> difference, particularly during noisy periods or contests.
>
> The issue is really when will all those bits go to a logic 1. With
> 16 bits, it will be ~96 db where db=20log V2/V1. I know this is not what
> most perceive, but it's true the A/D convertor is a voltage sensitive
> and not a power sensitive device. There are some other interesting
> subtleties like how much dynamic range do you really need, etc. Since I
> haven't had my first cup of coffee yet, I think I would not like to get
> in to those at this time.
>
> 73,
> Barry
> K3NDM
>
> On 8/21/2012 10:13 AM, Joe Subich, W4TV wrote:
>>> However, this card is not current; I think the 0404 replaces it.
>>> Someone can address this for you.
>> The current version is eMU 0204 - approximately $125 at places
>> like B&H Photo Video.
>>
>>> You really do want a 24 bit card and not 16 bit one.
>> Unless you need the high sample frequency for wide panadapter service,
>> any well designed 16 bit/48 KHz USB sound device will provide all the
>> performance you need at less than 1/4 the price of something like the
>> eMU 0204.
>>
>> > The other thing is that that card should have low internal noise;
>>
>> This is *the most important* determinant of performance. Internal
>> noise dramatically reduces the effective dynamic range of the sound
>> card.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 8/20/2012 4:40 PM, Barry LaZar wrote:
>>> Howie,
>>> The dongles I have seen are not spectacular. They are about on par
>>> with your average stereo laptop soundcard, OK but not great. I use a
>>> E-MU0202 from Creative Labs. This card is a 24 bit card that can sample
>>> beyond what Elecraft recommends. However, this card is not current; I
>>> think the 0404 replaces it. Someone can address this for you. You really
>>> do want a 24 bit card and not 16 bit one. The other thing is that that
>>> card should have low internal noise; the high end Creative Labs card
>>> meet this as does several others.
>>>
>>> There are a number of software packages around that you can use. I
>>> use NaP3 because it can control the KX3 and allows me to use VAC so that
>>> I can pipe the output to FLDIGI for reading the digial modes. I have
>>> essentially a full up computer controlled SDR that I can take out for
>>> Field Day and operate portable with knobs and a battery. It's the craziest!.
>>>
>>> I think, once you have it all lashed up, you will really have some
>>> fun. Good luck and do use a good card with ASIO drivers for best
>>> performance.
>>>
>>> 73,
>>> Barry
>>> K3NDM
>>>
>>>
>>> On 8/20/2012 12:37 AM, Howard Hoyt wrote:
>>>> Hi,
>>>>
>>>> I have been following the fun on this reflector while awaiting my KX3
>>>> (next Friday!). I am very interested in using the I&Q outs to interface
>>>> with my laptop, and as many have noted, you need a good, compatible
>>>> sound device to have a usable panadapter display. Does any one have
>>>> experience with a 192k sampling USB sound dongle for their laptop?
>>>>
>>>> TIA!
>>>>
>>>> Howie
>>>>
>>>> Howard Hoyt - WA4PSC
>>>> CE - WXYC-FM 89.3
>>>> UNC Chapel Hill, NC
>>>> www.wxyc.org
>>>> 1st on the internet
>>>> ______________________________________________________________
>>>> Elecraft mailing list
>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>> Post: mailto:[hidden email]
>>>>
>>>> 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:[hidden email]
>>>
>>> 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:[hidden email]
>>
>> 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:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
>

Barry K3NDM

Re: USB sound dongle

In reply to this post by Jim Brown-10

I concede that a lot of 24 bit cards are no better than 16 bits.
However, I stand by what I said that it is better to use a 24 bit A/D.

It is also true that most receivers are externally noise limited up
through around 15 meters. And, that gets to a design subtlety known as
proper gain distribution in the receive chain and proper noise figure
design, It sure makes little sense to design a radio that has a 15db
noise figure for say 80 meters where excess external noise might be
around 80db; I suggest CCIR-322 as a reference. But that doesn't mean
one should run his radio at wide open gain from 160-10 meters. Yet, we
hams do that most of the time. It would be a surprise to me if more of
us didn't complain about overload.

Having said all of that and possibly adding to the fog of this
discussion, I would suggest that 80-90 db would probably satisfy most,
most of the time. The exceptions might be contests and 40 meters in the
evening when the international BC gets going full bore. But, that
should be based on a 10log function and not a 20log function. A good
sound card would be my recommendation if you are doing what I do, run
the KX3 as SDR ala FlexRadio. If all you plan to do is use SDR software
for panadapter purposes, It probably doesn't make a lot of difference.

The technology is here today to go first class, or nearly so, so why
not. If you have a KX3, you are right up there, so why not get a good
card and finish the job for another $100-$150. The software is free.

73,
Barry
K3NDM

On 8/21/2012 11:18 AM, Jim Brown wrote:

> On 8/21/2012 7:48 AM, Barry LaZar wrote:
>> However, 24 bits of
>> quantization will get you a better dynamic range.
> Not if the dynamic range of the analog electronics limits it, which is
> what Joe has pointed out. Often those extra bits are "advertising bits"
> -- they fool those who don't know any better into believing that more
> bits is better. Actually, it's far more important to optimize the
> signal level that the A/D converter sees. That's why I like the Tascam
> USB interface better than the Numark -- it has a much greater range of
> gain adjustment and a clip light on the front panel. That allows me to
> easily optimize the 90 dB or so of dynamic range that its 16 bits provides.
>
> Besides -- the 90 dB dynamic range provided by a decent 16-bit A/D is
> probably more than most hams will ever see at the audio output of their
> radios. While the radio itself has much greater dynamic range, the
> WORKING dynamic range is limited by noise received by the antenna that
> is often 30-50 dB greater than the electrical noise levels inside the
> radio.
>
> 73, Jim K9YC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Barry K3NDM

Re: USB sound dongle

In reply to this post by Joe Subich, W4TV-4

Joe,
I agree with most all of it except the end. That's a discussion
many have been involved in for the last 10 years that I know of.

You are right on when you say a 16 bit A/D will work fine for the
times you are taking the line out out for the demoded audio. I seriously
doubt that many communications receivers' audio have the dynamic range
of the A/D following.

I do use the raw I and Q out of my KX3. It's one of the best
selling features of the radio, besides its inherent good performance.
Interestingly enough, I pipe the output of my 24 bit card which is used
for basic demod to my 16 bit card for digital work. And, why not. I
control the level going into the latter card directly so that it doesn't
overload. In other words, I might be viewed as cheating. But, it does
work great. I do highly recommend some form of this to anyone who wants
to try something that is fun and effective. I do admit it had it
frustrations, but the result has been very pleasing. My next step is to
get a cable that I can feed audio back into the mic connector and
control the PTT.

73,
Barry
K3NDM

On 8/21/2012 2:28 PM, Joe Subich, W4TV wrote:

> On 8/21/2012 11:18 AM, Jim Brown wrote:
> > On 8/21/2012 7:48 AM, Barry LaZar wrote:
>>> However, 24 bits of quantization will get you a better dynamic
>>> range.
> >
>> Not if the dynamic range of the analog electronics limits it, which
>> is what Joe has pointed out. Often those extra bits are "advertising
>> bits" -- they fool those who don't know any better into believing
>> that more bits is better.
> There are two issues here -
>
> First most amateurs run their digital software from "line out" or the
> demodulated audio from the transceiver. The demodulated audio has
> generally been through at least one A to D to A cycle and the noise
> floor is simply too high to take advantage of even the theoretical 96
> dB dynamic range of a 16 bit sound card.
>
> Now, if one is looking at the "raw" I/Q RF/IF or direct downconversion
> audio 24 bits "might" be usable *IF* the noise floor is low enough (a
> real *IF* with off the air signals) and any mixers and amplifiers are
> really linear through the theoretical 138 dB dynamic range *without* AGC.
>
> None of this addresses the noise floor and dynamic range of any preamp
> in the sound card ... it only looks at the theoretical dynamic range
> of the analog to digital converter.
>
> Then there is an additional consideration pointed out by Chen in a
> private e-mail - properly designed software can achieve dynamic range
> (sensitivity) *better than* the A to D converter (that is, it can
> "receive into the noise") by applying proper lowpass filtering and
> decimation. I know Chen uses decimation even with 16 bit cards in
> cocoaModem but it does not appear that any of the Windows centric
> digital software does so since many are based on 11025 or 12000 Hz
> sample rates and effectively throw away the potential processing gain
> by not performing any lowpass filtering in the 44100/48000 to 11025
> or 12000 sample rate downconversion.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 8/21/2012 11:18 AM, Jim Brown wrote:
>> On 8/21/2012 7:48 AM, Barry LaZar wrote:
>>> However, 24 bits of
>>> quantization will get you a better dynamic range.
>> Not if the dynamic range of the analog electronics limits it, which is
>> what Joe has pointed out. Often those extra bits are "advertising bits"
>> -- they fool those who don't know any better into believing that more
>> bits is better. Actually, it's far more important to optimize the
>> signal level that the A/D converter sees. That's why I like the Tascam
>> USB interface better than the Numark -- it has a much greater range of
>> gain adjustment and a clip light on the front panel. That allows me to
>> easily optimize the 90 dB or so of dynamic range that its 16 bits provides.
>>
>> Besides -- the 90 dB dynamic range provided by a decent 16-bit A/D is
>> probably more than most hams will ever see at the audio output of their
>> radios. While the radio itself has much greater dynamic range, the
>> WORKING dynamic range is limited by noise received by the antenna that
>> is often 30-50 dB greater than the electrical noise levels inside the
>> radio.
>>
>> 73, Jim K9YC
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> 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:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Barry K3NDM

Re: USB sound dongle

In reply to this post by Joe Subich, W4TV-4

Joe,
I think I just figured out we are not necessarily comparing apples
to apples. I just responded to a note you wrote on this reflector that
caused me to review what we are saying. You are correct of course if we
allow our basic radios to do their thing without our involvement and
then we do an A/D afterward.

You are also correct in pointing out that all of our radios are
externally noise limited today. However, the issue of USEFUL dynamic
range is only eluded to by you. Antenna noise is the vector sum of all
of the noise in the environment, regardless of how it got there. It's
true living where I do, in an urban environment with power lines and
gasoline engines, I'll never see antenna noise that looks like the
atmospheric noise that can be seen down on the farm. And yes, I'm a
little idealistic in my designs, but during a contest or near the BC
stations your electronics and software are going to be tested. And
remember that the international BC guys design to hit urban
environments, meaning lots pf power that will assure high S/N ratios on
you communications receiver, not necessarily that cheapy SWL radio from
Radio Shack.

I am not using demoded line out audio from my KX3. I use the raw I
& Q data. I think that is what we missed in our past exchanges. That
means I can really use the dynamic range of a 24 bit card because I set
things so that noise doesn't control my A/D any more than a few bits. I
believe you need to so it this way just so you don't miss anything. But,
we can discuss that in the future.

73,
Barry
K3NDM

On 8/21/2012 2:57 PM, Joe Subich, W4TV wrote:

> Barry,
>
>> The issue is really when will all those bits go to a logic 1. With 16
>> bits, it will be ~96 db where db=20log V2/V1. I know this is not
>> what most perceive, but it's true the A/D convertor is a voltage
>> sensitive and not a power sensitive device.
> The issue with dynamic range is just as much the ability of all those
> bits to go to logic 0. If the receiver has so much noise - whether
> atmospheric noise at the antenna, thermal noise in the IF, masking
> due to A/D/A conversions in the demodulator, or thermal noise/hum in
> the audio output stages, the sound card will never achieve even the
> theoretical 96 dB dynamic range for 16 bit A/D.
>
> Add to that, switching noise on the typical USB power line, the lack of
> secondary regulation in inexpensive USB sound "dongles", the failure
> to provide a separate *regulated* reference for the ADC, failures to
> provide *regulated* references for op-amp preamps, lack of attention
> to grounding and bypassing, etc. and the noise floor in commodity USB
> sound devices (and "inexpensive" amateur products) further limits the
> achievable dynamic range.
>
> With external noise sources, it doesn't matter if one has a 16 or 24
> bit ADC, the achievable dynamic range will be limited to the area
> between *all* of the noise contributors and the maximum voltage
> handling capability (typically < 5.0V) of the ADC ... or between
> 65 and 70 dB in many of the commodity and inexpensive amateur
> devices.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 8/21/2012 10:48 AM, Barry LaZar wrote:
>> Joe,
>> I agree with your comment on internal noise. However, 24 bits of
>> quantization will get you a better dynamic range. But, It becomes an
>> interesting point when the effects of receiver AGC gets into the
>> discussion on this point. Someone in a much earlier post said that the
>> receiver's AGC would keep things within bounds for a 16 bit card; he may
>> be correct. But, if you run without AGC on the receiver and use AGC
>> developed by the SDR software, having those extra bits will make a
>> difference, particularly during noisy periods or contests.
>>
>> The issue is really when will all those bits go to a logic 1. With
>> 16 bits, it will be ~96 db where db=20log V2/V1. I know this is not what
>> most perceive, but it's true the A/D convertor is a voltage sensitive
>> and not a power sensitive device. There are some other interesting
>> subtleties like how much dynamic range do you really need, etc. Since I
>> haven't had my first cup of coffee yet, I think I would not like to get
>> in to those at this time.
>>
>> 73,
>> Barry
>> K3NDM
>>
>> On 8/21/2012 10:13 AM, Joe Subich, W4TV wrote:
>>>> However, this card is not current; I think the 0404 replaces it.
>>>> Someone can address this for you.
>>> The current version is eMU 0204 - approximately $125 at places
>>> like B&H Photo Video.
>>>
>>>> You really do want a 24 bit card and not 16 bit one.
>>> Unless you need the high sample frequency for wide panadapter service,
>>> any well designed 16 bit/48 KHz USB sound device will provide all the
>>> performance you need at less than 1/4 the price of something like the
>>> eMU 0204.
>>>
>>> > The other thing is that that card should have low internal noise;
>>>
>>> This is *the most important* determinant of performance. Internal
>>> noise dramatically reduces the effective dynamic range of the sound
>>> card.
>>>
>>> 73,
>>>
>>> ... Joe, W4TV
>>>
>>>
>>> On 8/20/2012 4:40 PM, Barry LaZar wrote:
>>>> Howie,
>>>> The dongles I have seen are not spectacular. They are about on par
>>>> with your average stereo laptop soundcard, OK but not great. I use a
>>>> E-MU0202 from Creative Labs. This card is a 24 bit card that can sample
>>>> beyond what Elecraft recommends. However, this card is not current; I
>>>> think the 0404 replaces it. Someone can address this for you. You really
>>>> do want a 24 bit card and not 16 bit one. The other thing is that that
>>>> card should have low internal noise; the high end Creative Labs card
>>>> meet this as does several others.
>>>>
>>>> There are a number of software packages around that you can use. I
>>>> use NaP3 because it can control the KX3 and allows me to use VAC so that
>>>> I can pipe the output to FLDIGI for reading the digial modes. I have
>>>> essentially a full up computer controlled SDR that I can take out for
>>>> Field Day and operate portable with knobs and a battery. It's the craziest!.
>>>>
>>>> I think, once you have it all lashed up, you will really have some
>>>> fun. Good luck and do use a good card with ASIO drivers for best
>>>> performance.
>>>>
>>>> 73,
>>>> Barry
>>>> K3NDM
>>>>
>>>>
>>>> On 8/20/2012 12:37 AM, Howard Hoyt wrote:
>>>>> Hi,
>>>>>
>>>>> I have been following the fun on this reflector while awaiting my KX3
>>>>> (next Friday!). I am very interested in using the I&Q outs to interface
>>>>> with my laptop, and as many have noted, you need a good, compatible
>>>>> sound device to have a usable panadapter display. Does any one have
>>>>> experience with a 192k sampling USB sound dongle for their laptop?
>>>>>
>>>>> TIA!
>>>>>
>>>>> Howie
>>>>>
>>>>> Howard Hoyt - WA4PSC
>>>>> CE - WXYC-FM 89.3
>>>>> UNC Chapel Hill, NC
>>>>> www.wxyc.org
>>>>> 1st on the internet
>>>>> ______________________________________________________________
>>>>> Elecraft mailing list
>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>> Post: mailto:[hidden email]
>>>>>
>>>>> 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:[hidden email]
>>>>
>>>> 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:[hidden email]
>>>
>>> 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:[hidden email]
>>
>> 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:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Joe Subich, W4TV-4

Re: USB sound dongle

> I am not using demoded line out audio from my KX3. I use the raw I &
> Q data. I think that is what we missed in our past exchanges. That
> means I can really use the dynamic range of a 24 bit card because I
> set things so that noise doesn't control my A/D any more than a few
> bits.

The hype by certain manufacturers of direct down conversion I/Q rigs
aside, I do not believe that direct I/Q to a 24 bit soundcard provides
the necessary dynamic range. First as K9YC has alluded to, far too
many pf the low level bits are "advertising bits" - they are either
lost in the low level noise or exceed the clipping level in prior
stages. Secondly AGC is always an issue leading to significant
issues with blocking dynamic range problems ("window" pumping).

Direct sampling architecture may provide the ultimate solution in
those areas but I still feel it will be necessary to wait on the
development of cost effective a 28 or 32 bit ADC in order to obtain
the performance necessary for a true 150 dB (MDS= -145 dBm) spurious
free dynamic range in the presence of multiple strong signals. Until
then, well designed 16 bit ADC sound devices fed with demodulated audio
will continue to be the most cost effective high performance solution
for mainstream applications.

73,

... Joe, W4TV

On 8/21/2012 6:17 PM, Barry LaZar wrote:

> Joe,
> I think I just figured out we are not necessarily comparing apples
> to apples. I just responded to a note you wrote on this reflector that
> caused me to review what we are saying. You are correct of course if we
> allow our basic radios to do their thing without our involvement and
> then we do an A/D afterward.
>
> You are also correct in pointing out that all of our radios are
> externally noise limited today. However, the issue of USEFUL dynamic
> range is only eluded to by you. Antenna noise is the vector sum of all
> of the noise in the environment, regardless of how it got there. It's
> true living where I do, in an urban environment with power lines and
> gasoline engines, I'll never see antenna noise that looks like the
> atmospheric noise that can be seen down on the farm. And yes, I'm a
> little idealistic in my designs, but during a contest or near the BC
> stations your electronics and software are going to be tested. And
> remember that the international BC guys design to hit urban
> environments, meaning lots pf power that will assure high S/N ratios on
> you communications receiver, not necessarily that cheapy SWL radio from
> Radio Shack.
>
> I am not using demoded line out audio from my KX3. I use the raw I
> & Q data. I think that is what we missed in our past exchanges. That
> means I can really use the dynamic range of a 24 bit card because I set
> things so that noise doesn't control my A/D any more than a few bits. I
> believe you need to so it this way just so you don't miss anything. But,
> we can discuss that in the future.
>
> 73,
> Barry
> K3NDM
>
> On 8/21/2012 2:57 PM, Joe Subich, W4TV wrote:
>> Barry,
>>
>>> The issue is really when will all those bits go to a logic 1. With 16
>>> bits, it will be ~96 db where db=20log V2/V1. I know this is not
>>> what most perceive, but it's true the A/D convertor is a voltage
>>> sensitive and not a power sensitive device.
>> The issue with dynamic range is just as much the ability of all those
>> bits to go to logic 0. If the receiver has so much noise - whether
>> atmospheric noise at the antenna, thermal noise in the IF, masking
>> due to A/D/A conversions in the demodulator, or thermal noise/hum in
>> the audio output stages, the sound card will never achieve even the
>> theoretical 96 dB dynamic range for 16 bit A/D.
>>
>> Add to that, switching noise on the typical USB power line, the lack of
>> secondary regulation in inexpensive USB sound "dongles", the failure
>> to provide a separate *regulated* reference for the ADC, failures to
>> provide *regulated* references for op-amp preamps, lack of attention
>> to grounding and bypassing, etc. and the noise floor in commodity USB
>> sound devices (and "inexpensive" amateur products) further limits the
>> achievable dynamic range.
>>
>> With external noise sources, it doesn't matter if one has a 16 or 24
>> bit ADC, the achievable dynamic range will be limited to the area
>> between *all* of the noise contributors and the maximum voltage
>> handling capability (typically < 5.0V) of the ADC ... or between
>> 65 and 70 dB in many of the commodity and inexpensive amateur
>> devices.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 8/21/2012 10:48 AM, Barry LaZar wrote:
>>> Joe,
>>> I agree with your comment on internal noise. However, 24 bits of
>>> quantization will get you a better dynamic range. But, It becomes an
>>> interesting point when the effects of receiver AGC gets into the
>>> discussion on this point. Someone in a much earlier post said that the
>>> receiver's AGC would keep things within bounds for a 16 bit card; he may
>>> be correct. But, if you run without AGC on the receiver and use AGC
>>> developed by the SDR software, having those extra bits will make a
>>> difference, particularly during noisy periods or contests.
>>>
>>> The issue is really when will all those bits go to a logic 1. With
>>> 16 bits, it will be ~96 db where db=20log V2/V1. I know this is not what
>>> most perceive, but it's true the A/D convertor is a voltage sensitive
>>> and not a power sensitive device. There are some other interesting
>>> subtleties like how much dynamic range do you really need, etc. Since I
>>> haven't had my first cup of coffee yet, I think I would not like to get
>>> in to those at this time.
>>>
>>> 73,
>>> Barry
>>> K3NDM
>>>
>>> On 8/21/2012 10:13 AM, Joe Subich, W4TV wrote:
>>>>> However, this card is not current; I think the 0404 replaces it.
>>>>> Someone can address this for you.
>>>> The current version is eMU 0204 - approximately $125 at places
>>>> like B&H Photo Video.
>>>>
>>>>> You really do want a 24 bit card and not 16 bit one.
>>>> Unless you need the high sample frequency for wide panadapter service,
>>>> any well designed 16 bit/48 KHz USB sound device will provide all the
>>>> performance you need at less than 1/4 the price of something like the
>>>> eMU 0204.
>>>>
>>>> > The other thing is that that card should have low internal noise;
>>>>
>>>> This is *the most important* determinant of performance. Internal
>>>> noise dramatically reduces the effective dynamic range of the sound
>>>> card.
>>>>
>>>> 73,
>>>>
>>>> ... Joe, W4TV
>>>>
>>>>
>>>> On 8/20/2012 4:40 PM, Barry LaZar wrote:
>>>>> Howie,
>>>>> The dongles I have seen are not spectacular. They are about on par
>>>>> with your average stereo laptop soundcard, OK but not great. I use a
>>>>> E-MU0202 from Creative Labs. This card is a 24 bit card that can sample
>>>>> beyond what Elecraft recommends. However, this card is not current; I
>>>>> think the 0404 replaces it. Someone can address this for you. You really
>>>>> do want a 24 bit card and not 16 bit one. The other thing is that that
>>>>> card should have low internal noise; the high end Creative Labs card
>>>>> meet this as does several others.
>>>>>
>>>>> There are a number of software packages around that you can use. I
>>>>> use NaP3 because it can control the KX3 and allows me to use VAC so that
>>>>> I can pipe the output to FLDIGI for reading the digial modes. I have
>>>>> essentially a full up computer controlled SDR that I can take out for
>>>>> Field Day and operate portable with knobs and a battery. It's the craziest!.
>>>>>
>>>>> I think, once you have it all lashed up, you will really have some
>>>>> fun. Good luck and do use a good card with ASIO drivers for best
>>>>> performance.
>>>>>
>>>>> 73,
>>>>> Barry
>>>>> K3NDM
>>>>>
>>>>>
>>>>> On 8/20/2012 12:37 AM, Howard Hoyt wrote:
>>>>>> Hi,
>>>>>>
>>>>>> I have been following the fun on this reflector while awaiting my KX3
>>>>>> (next Friday!). I am very interested in using the I&Q outs to interface
>>>>>> with my laptop, and as many have noted, you need a good, compatible
>>>>>> sound device to have a usable panadapter display. Does any one have
>>>>>> experience with a 192k sampling USB sound dongle for their laptop?
>>>>>>
>>>>>> TIA!
>>>>>>
>>>>>> Howie
>>>>>>
>>>>>> Howard Hoyt - WA4PSC
>>>>>> CE - WXYC-FM 89.3
>>>>>> UNC Chapel Hill, NC
>>>>>> www.wxyc.org
>>>>>> 1st on the internet
>>>>>> ______________________________________________________________
>>>>>> Elecraft mailing list
>>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>> Post: mailto:[hidden email]
>>>>>>
>>>>>> 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:[hidden email]
>>>>>
>>>>> 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:[hidden email]
>>>>
>>>> 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:[hidden email]
>>>
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>>> Please help support this email list: http://www.qsl.net/donate.html
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>> ______________________________________________________________
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>>
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>
> ______________________________________________________________
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Barry K3NDM

Re: USB sound dongle

In reply to this post by Tony Estep

Tony,
You are correct. I do use 2 cards. My "good one", EMU-0202, takes
the I & Q data from the KX3 and gives me demoded audio which is piped
into a follow on digital program using VAC. My laptop's sound card
takes the audio from VAC for use with my digital software It just never
occurred to me to try anything else. I use FLDIGI and MixW as the follow
on software. I like both.

BTW: The KX3 manual implies that going to 192KHz is not the best
idea as there is fall off in response that far out. It's hardly
noticeable at 48KHz, so I use that. As I am tuning the KX3 in sync with
what I do on the screen, It hasn't been a problem for me. I can change
the sampling rate to greater than 48KHz if I want. I just don't.

After you get it all sorted out, it should knock your socks off.
It's been the most fun that I've had in a while.

73,
Barry
K3NDM

On 8/21/2012 11:38 AM, Tony Estep wrote:

> On Mon, Aug 20, 2012 at 3:40 PM, Barry LaZar <[hidden email]> wrote:
>
>> ....I use NaP3 because it can control the KX3 and allows me to use VAC so
>> that
>> I can pipe the output ....
> ===========
> Note that to do this you have to have 2 sound cards, one for the I-Q and
> one for the digi program. I found this out the dumb way by actually setting
> it up to use my internal 192K sound module for both. Surprisingly, it
> actually works after a fashion, but of course the digi program is listening
> not only to what's coming from the receiver in NaP3 but also to the
> wideband I and Q signals, and the NaP3 program is listening not only to I
> and Q, but also to its own output. Took a while before I eventually I
> realized my mistake.
>
> Tony KT0NY
>
>

Barry K3NDM

Re: USB sound dongle

In reply to this post by Joe Subich, W4TV-4

Years and years ago, I was involved in an area that had to do with
propagation and circuit path analysis. I was in a room full of academics
when the hot discussion began. The issue was what is the instantaneous
dynamic range of the environment. There were two schools of thought. One
said that the environment had a dynamic range of 120db and the other
said 144db. What is missed by outsiders to this is the question for what
period of time? As path reliability is quoted as a probability, time
matters. As it turns out all of these folk were fighting over a period
represented by less than 5%. And, most of the published environmental
data is for the median, 50% of the time.

There was a study that someone wrote and published a number of years ago
in QST that stated 80db was all you need as a ham. And, the author gave
his reasons. I think it should be a bit more, but we could start another
thread on that issue.

I have done direct down conversion SDRs using 16 bit 100MHz A/Ds.
However, you really don't get 100MHz bandwidth as Nyguist says you need
to sample at least 2X the bandwidth of interest. And adding a little
practicality to that, you really don't get 1/2 the bandwidth either as
you would like some over-sampling. If you want to play with this, Analog
Devices makes the A/D that I used. However they ain't cheap.

I can assure you that direct sampling works. There are some real tricks
involved known to the DSP engineers, of which I am not one. But, it
works and works well.

To account for what you are concerned with, what you really want is an
inverse taper of receiver gain, less gain at the bottom and more at the
top. By doing this, environmental noise will less likely overwhelm your
A/D, yet total system noise figure can be maintained such that you will
always be externally noise limited. And secondarily, Don't use too much
gain up front. Distribute the gain along the receiver chain to keep
dynamic range. This latter point is how you get quiet, high dynamic
range, sensitive receivers.

Spending more than say $150 for a really good sound card probably
doesn't make a whole lot of sense when using a KX3. But, I admit I do
like the idea of the capability to mess with the thing as I do. If
you're saner than I, use the sound card in you computer. It will work
quite well when using the line out. You just miss the fun of an
additional play toy.

73,
Barry
K3NDM

On 8/21/2012 8:37 PM, Joe Subich, W4TV wrote:

>> I am not using demoded line out audio from my KX3. I use the raw I &
>> Q data. I think that is what we missed in our past exchanges. That
>> means I can really use the dynamic range of a 24 bit card because I
>> set things so that noise doesn't control my A/D any more than a few
>> bits.
> The hype by certain manufacturers of direct down conversion I/Q rigs
> aside, I do not believe that direct I/Q to a 24 bit soundcard provides
> the necessary dynamic range. First as K9YC has alluded to, far too
> many pf the low level bits are "advertising bits" - they are either
> lost in the low level noise or exceed the clipping level in prior
> stages. Secondly AGC is always an issue leading to significant
> issues with blocking dynamic range problems ("window" pumping).
>
> Direct sampling architecture may provide the ultimate solution in
> those areas but I still feel it will be necessary to wait on the
> development of cost effective a 28 or 32 bit ADC in order to obtain
> the performance necessary for a true 150 dB (MDS= -145 dBm) spurious
> free dynamic range in the presence of multiple strong signals. Until
> then, well designed 16 bit ADC sound devices fed with demodulated audio
> will continue to be the most cost effective high performance solution
> for mainstream applications.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 8/21/2012 6:17 PM, Barry LaZar wrote:
>> Joe,
>> I think I just figured out we are not necessarily comparing apples
>> to apples. I just responded to a note you wrote on this reflector that
>> caused me to review what we are saying. You are correct of course if we
>> allow our basic radios to do their thing without our involvement and
>> then we do an A/D afterward.
>>
>> You are also correct in pointing out that all of our radios are
>> externally noise limited today. However, the issue of USEFUL dynamic
>> range is only eluded to by you. Antenna noise is the vector sum of all
>> of the noise in the environment, regardless of how it got there. It's
>> true living where I do, in an urban environment with power lines and
>> gasoline engines, I'll never see antenna noise that looks like the
>> atmospheric noise that can be seen down on the farm. And yes, I'm a
>> little idealistic in my designs, but during a contest or near the BC
>> stations your electronics and software are going to be tested. And
>> remember that the international BC guys design to hit urban
>> environments, meaning lots pf power that will assure high S/N ratios on
>> you communications receiver, not necessarily that cheapy SWL radio from
>> Radio Shack.
>>
>> I am not using demoded line out audio from my KX3. I use the raw I
>> & Q data. I think that is what we missed in our past exchanges. That
>> means I can really use the dynamic range of a 24 bit card because I set
>> things so that noise doesn't control my A/D any more than a few bits. I
>> believe you need to so it this way just so you don't miss anything. But,
>> we can discuss that in the future.
>>
>> 73,
>> Barry
>> K3NDM
>>
>> On 8/21/2012 2:57 PM, Joe Subich, W4TV wrote:
>>> Barry,
>>>
>>>> The issue is really when will all those bits go to a logic 1. With 16
>>>> bits, it will be ~96 db where db=20log V2/V1. I know this is not
>>>> what most perceive, but it's true the A/D convertor is a voltage
>>>> sensitive and not a power sensitive device.
>>> The issue with dynamic range is just as much the ability of all those
>>> bits to go to logic 0. If the receiver has so much noise - whether
>>> atmospheric noise at the antenna, thermal noise in the IF, masking
>>> due to A/D/A conversions in the demodulator, or thermal noise/hum in
>>> the audio output stages, the sound card will never achieve even the
>>> theoretical 96 dB dynamic range for 16 bit A/D.
>>>
>>> Add to that, switching noise on the typical USB power line, the lack of
>>> secondary regulation in inexpensive USB sound "dongles", the failure
>>> to provide a separate *regulated* reference for the ADC, failures to
>>> provide *regulated* references for op-amp preamps, lack of attention
>>> to grounding and bypassing, etc. and the noise floor in commodity USB
>>> sound devices (and "inexpensive" amateur products) further limits the
>>> achievable dynamic range.
>>>
>>> With external noise sources, it doesn't matter if one has a 16 or 24
>>> bit ADC, the achievable dynamic range will be limited to the area
>>> between *all* of the noise contributors and the maximum voltage
>>> handling capability (typically < 5.0V) of the ADC ... or between
>>> 65 and 70 dB in many of the commodity and inexpensive amateur
>>> devices.
>>>
>>> 73,
>>>
>>> ... Joe, W4TV
>>>
>>>
>>> On 8/21/2012 10:48 AM, Barry LaZar wrote:
>>>> Joe,
>>>> I agree with your comment on internal noise. However, 24 bits of
>>>> quantization will get you a better dynamic range. But, It becomes an
>>>> interesting point when the effects of receiver AGC gets into the
>>>> discussion on this point. Someone in a much earlier post said that the
>>>> receiver's AGC would keep things within bounds for a 16 bit card; he may
>>>> be correct. But, if you run without AGC on the receiver and use AGC
>>>> developed by the SDR software, having those extra bits will make a
>>>> difference, particularly during noisy periods or contests.
>>>>
>>>> The issue is really when will all those bits go to a logic 1. With
>>>> 16 bits, it will be ~96 db where db=20log V2/V1. I know this is not what
>>>> most perceive, but it's true the A/D convertor is a voltage sensitive
>>>> and not a power sensitive device. There are some other interesting
>>>> subtleties like how much dynamic range do you really need, etc. Since I
>>>> haven't had my first cup of coffee yet, I think I would not like to get
>>>> in to those at this time.
>>>>
>>>> 73,
>>>> Barry
>>>> K3NDM
>>>>
>>>> On 8/21/2012 10:13 AM, Joe Subich, W4TV wrote:
>>>>>> However, this card is not current; I think the 0404 replaces it.
>>>>>> Someone can address this for you.
>>>>> The current version is eMU 0204 - approximately $125 at places
>>>>> like B&H Photo Video.
>>>>>
>>>>>> You really do want a 24 bit card and not 16 bit one.
>>>>> Unless you need the high sample frequency for wide panadapter service,
>>>>> any well designed 16 bit/48 KHz USB sound device will provide all the
>>>>> performance you need at less than 1/4 the price of something like the
>>>>> eMU 0204.
>>>>>
>>>>> > The other thing is that that card should have low internal noise;
>>>>>
>>>>> This is *the most important* determinant of performance. Internal
>>>>> noise dramatically reduces the effective dynamic range of the sound
>>>>> card.
>>>>>
>>>>> 73,
>>>>>
>>>>> ... Joe, W4TV
>>>>>
>>>>>
>>>>> On 8/20/2012 4:40 PM, Barry LaZar wrote:
>>>>>> Howie,
>>>>>> The dongles I have seen are not spectacular. They are about on par
>>>>>> with your average stereo laptop soundcard, OK but not great. I use a
>>>>>> E-MU0202 from Creative Labs. This card is a 24 bit card that can sample
>>>>>> beyond what Elecraft recommends. However, this card is not current; I
>>>>>> think the 0404 replaces it. Someone can address this for you. You really
>>>>>> do want a 24 bit card and not 16 bit one. The other thing is that that
>>>>>> card should have low internal noise; the high end Creative Labs card
>>>>>> meet this as does several others.
>>>>>>
>>>>>> There are a number of software packages around that you can use. I
>>>>>> use NaP3 because it can control the KX3 and allows me to use VAC so that
>>>>>> I can pipe the output to FLDIGI for reading the digial modes. I have
>>>>>> essentially a full up computer controlled SDR that I can take out for
>>>>>> Field Day and operate portable with knobs and a battery. It's the craziest!.
>>>>>>
>>>>>> I think, once you have it all lashed up, you will really have some
>>>>>> fun. Good luck and do use a good card with ASIO drivers for best
>>>>>> performance.
>>>>>>
>>>>>> 73,
>>>>>> Barry
>>>>>> K3NDM
>>>>>>
>>>>>>
>>>>>> On 8/20/2012 12:37 AM, Howard Hoyt wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> I have been following the fun on this reflector while awaiting my KX3
>>>>>>> (next Friday!). I am very interested in using the I&Q outs to interface
>>>>>>> with my laptop, and as many have noted, you need a good, compatible
>>>>>>> sound device to have a usable panadapter display. Does any one have
>>>>>>> experience with a 192k sampling USB sound dongle for their laptop?
>>>>>>>
>>>>>>> TIA!
>>>>>>>
>>>>>>> Howie
>>>>>>>
>>>>>>> Howard Hoyt - WA4PSC
>>>>>>> CE - WXYC-FM 89.3
>>>>>>> UNC Chapel Hill, NC
>>>>>>> www.wxyc.org
>>>>>>> 1st on the internet
>>>>>>> ______________________________________________________________
>>>>>>> Elecraft mailing list
>>>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>>> Post: mailto:[hidden email]
>>>>>>>
>>>>>>> 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:[hidden email]
>>>>>>
>>>>>> 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:[hidden email]
>>>>>
>>>>> This list hosted by: http://www.qsl.net
>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>
>>>> ______________________________________________________________
>>>> Elecraft mailing list
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>>>> Post: mailto:[hidden email]
>>>>
>>>> This list hosted by: http://www.qsl.net
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>>>>
>>> ______________________________________________________________
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>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>> ______________________________________________________________
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>>
> ______________________________________________________________
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Bill Frantz

Re: USB sound dongle

In reply to this post by hhoyt

The comments of Joe, Barry, and Jim just convince me that
nirvana for a K3 computer connection is to have the K3 digital
audio passed directly to the computer without translating it to
analog and back to digital. That D to A to D can't help the
quality of the system.

Cheers - Bill, AE6JV

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