The advantage of using an ASIO SOUND CARD when using your paddles with a software cw keyer on your computer

 

 A simple test was setup to determine how much latency there was,  

 from the time you tap one of the paddle handles, 

 until you actually hear the sidetone from your speaker or headphones, 

 when using two different approaches to computer audio.

 

 - DIRECT SOUND was compared to ASIO - 
 (with the BEHRINGER UCA222) 

DIRECT SOUND - took over 100 milliseconds 

ASIO - took less than 30 milliseconds 

Using an ASIO SOUND CARD reduces latency substantially to the point where it would be considered NEAR ZERO LATENCY - at less than 30 milliseconds. 

DIRECT SOUND is not ideal therefore, at over 100 milliseconds;  and potentially will be an obstacle and hindrance to sending precision morse code with your paddles and a software cw keyer application. 

NOTE: the behringer uca222 is a budget asio sound card 
and costs around 30 dollars. 
http://www.amazon.com/Behringer-UCA222-U-Control-Ultra-Low-Download... 

Views: 7015

Comment by Chuck aa0hw on January 17, 2013 at 7:20pm

HERE IS ANOTHER EXAMPLE OF WHY AN ASIO AUDIO DRIVER IS BETTER

FOR USING A SOFTWARE CW KEYER ON YOUR COMPUTER

- a test was run -  by sending a morse code dit stream at 25 words per minute.

This is a blended view of running the same test twice.  First test pictured on top uses an ASIO DRIVER and the second test on the bottom used a windows native audio kernel driver.  The windows native drivers were subject to interruptions and produced a morse code dit stream that was not steady in length of dits or dit spacing.  However, the ASIO driver produced much better results and very stable dit lengths and spacing.

Comment by Chuck aa0hw on January 17, 2013 at 7:24pm

HERE IS WHAT THE TEST PICTURED ABOVE SOUNDS LIKE:

 first is the ASIO DRIVER as pictured above (on top)

SENDING A MORSE CODE DIT STREAM AT 25 WPM USING AN ASIO DRIVER by chaseology

here is the windows native audio driver, audio example, of the dit stream pictured above (on the bottom)

SENDING A MORSE CODE DIT STREAM AT 25 WPM USING WINDOWS NATIVE AUDI... by chaseology

Comment by Chuck aa0hw on January 18, 2013 at 6:42am

The variance in timing is mostly coming from the amount of time of the spaces between the dits.  It is varying ~10 milliseconds. The spacing between dits is supposed to be about 48 milliseconds.  From viewing the AUDACITY SCREEN and measuring this spacing, it seems that when using a NON ASIO windows sound device,  there are many times during this dit stream test that the between dit space was 38 milliseconds. a 10 ms error.  The dit length however seemed to be consistent.  It is the spacing errors causing the poor sending.

- BELOW IS A BLENDED VIEW OF THIS ERROR IN SENDING BY WINDOWS AUDIO ENGINES -

- the shading represents the space between 2 dits, TOP VIEW is 48ms and bottom is 38ms -

Comment by Chuck aa0hw on January 18, 2013 at 7:27am

Windows audio drivers do even worse at higher speeds when sending morse code with a software cw keyer.  Here is a recording of an ASIO DRIVER first sending a dit stream at 37wpm followed by windows audio trying to send the dit stream at the same speed.  Listen for the "audio hiccups" -  from the space variance - during the 2nd part of this recording where the windows audio driver produces many errors in the morse code timing.

ASIO driver vs WINDOWS audio driver when sending morse code with a ... by chaseology

Comment by Chuck aa0hw on January 18, 2013 at 7:30am

The software cw keyer used in all of these tests - is MORSE KEYER

Comment by Chuck aa0hw on January 18, 2013 at 4:14pm

The latency of MORSE KEYER V3.0,  from the time you "tap" the iambic paddle handle, until you actually hear the cw tone,  when using a PRO ASIO SOUND CARD with its own ASIO DRIVER, is less than 10 milliseconds.  This is extremely good performance from both MORSE KEYER V3.0 and the ASIO DRIVER working together.  The PRO USB sound card used in this test,  is a KOMPLETE AUDIO 6.

The picture below shows a "slap" noise on the paddle at the beginning of the wave picture and then the start of the cw morse code audio tone.  The time between the "paddle slap" and the tone is less than 10 milliseconds.

NOTE: I was using a high end ASIO SOUND CARD for this test, which is why the latency is much better than when I tested latency using the BEHRINGER UCA222 budget asio sound card.   I am using a KOMPLETE AUDIO 6 ASIO sound card for this example.

Comment by Chuck aa0hw on January 18, 2013 at 4:45pm

Here is a blended view of comparing the "paddle tap test"  latency between the KOMPLETE AUDIO 6 asio sound card and the BEHRINGER UCA222 asio sound card.  The KOMPLETE is the waveform on top and to the left, the BEHRINGER is to the right and on the bottom.   The BEHRINGER is less than 30 milliseconds, and that would still be considered excellent latency performance.  You should not be able to notice 30 milliseconds of latency unless you are "looking" for it and strain your ears and mind to sense it.

Comment by Chuck aa0hw on January 21, 2013 at 10:40am

Here is a switch debounce circuit I use for MORSE KEYER - iambic paddle mode


DTR
- 4 - connected to iambic paddle ground

paddle dit connected to  DSR and paddle dah connected to CTS  (or vice versa)

(paddle dit and dah are connected at the top of the push button switches on circuit diagram)

Comment by Chuck aa0hw on January 21, 2013 at 10:57am

Here is a quick reference diagram of the pinout of a db9 serial connector as you would see it looking at your computer case or a usb2serial port adapter

Here is a picture of the db9 viewed as you look at the cable end itself,  that hooks to your serial com port on your computer case or usb2serial port adapter

Comment by Chuck aa0hw on January 21, 2013 at 1:41pm

Here is a video tutorial to show you how to hook up your paddles to your serial port and use a software cw keyer like MORSE KEYER to send near perfect morse code audio tones to your computer sound card. You can also set this up to use MORSE KEYER and your iambic paddles to send morse code audio tones out over the internet on online morse communities like - QSONET, HAMPSPHERE, CWCOM and iCW etc...You can even use this setup to key your rig for CW.

This video will demonstrate how to hook up your iambic paddles to the serial port of your computer in order to use a software cw keyer like MORSE KEYER. You will be able to send and hear morse code with your cw paddles in high fidelity, low latency, and excellent cw timing performance when using as ASIO SOUND CARD with its own ASIO DRIVER. You are also able to use this method at the same time, to send the same morse code audio tones generated by MORSE KEYER to go out over the internet on programs like QSONET, CWCOM, HAMSPHERE, iCW etc....

Here are the links mentioned in this video:
1. http://www.amazon.com/Behringer-UCA222-U-Control-Ultra-Low-Download...
2. http://www.behringer.com/EN/Products/UCA222.aspx
3. http://www.amazon.com/RS-232-Serial-Adapter-Windows-FTDI/dp/B004WL7...
4. http://www.radioshack.com/product/index.jsp?productId=2062214
5. http://www.zzounds.com/item--HOSYRA154
6. http://www.labbookpages.co.uk/electronics/debounce.html
7. http://www.db9-pinout.com/
8. http://qsonet.com/dahdidah.pdf
9. http://qrqcwnet.ning.com/profiles/blogs/the-advantage-of-using-an-a...
10. http://morse-rss-news.sourceforge.net/

NOTE: if your computer has a LINE IN audio jack, use that instead of the MIC IN jack. There is much less noise on the LINE IN jack.

NOTE: it may be best match all sample rates between the BEHRINGER, and the MIC or LINE input jack of your computer soundcard and all inputs and outputs, including STEREO MIX of the computer soundcard itself. You can select the sample rates in both the ASIO CONTROL of the BEHRINGER and the windows sound control screen.
see here: http://screencloud.net/v/ngzT
set everything listed on both the PLAYBACK and RECORDING tab of the windows control for both the BEHRINGER and your COMPUTER SOUND CARD to the same sample rate

NOTE: using an audio derived cw keying switch circuit, you can also use this setup
to key your rig, (need to turn off the sidetone of your rig though) The Behringer has an active - always on - headphone jack- and you can use that audio to go out to the input of an AUDIO DERIVED CW KEYING CIRCUIT, which will then key your rig for you...
so at the same time the audio from the BEHRINGER is going out from the LINE OUT JACKS, through a ground loop isolation audio cable to the input of your computer sound card, you can also at the same time, take that same audio out of the BEHRINGER headphone jack and connect it to an audio derived cw keying circuit and key your rig.
You can monitor the audio from your RIG's audio out, to the BEHRINGER LINE IN jacks, by using PEDALBOARD2 to transfer the audio from your BEHRINGER LINE INPUT over to the computer soundcard.
For more info go here: http://qrqcwnet.ning.com/profiles/blogs/the-advantage-of-using-an-a...
You will then not only hear your own cw audio tones made from MORSE KEYER from the BEHRINGER, but whatever is hooked to the LINE IN jacks of the BEHRINGER, ie, your rigs audio output, you can also hear that too.

You have to be able to monitor the audio coming into the MIC IN or LINE IN jack of your computer's native sound card - you must UNMUTE in the WINDOWS SOUND PROPERTIES, SPEAKERS PROPERTIES, Levels, the MICROPHONE or LINE IN slider...
if you do not have a slider control on this screen, this video tutorial will not work and you will have to search for a modification to force that "slider" to appear.
Please see this picture of the windows sound control for monitoring input by unmuting it and adjusting the volume slider here:
http://screencloud.net/v/cl8k

Here are some examples of audio derived cw keying circuits:
http://qrqcwnet.ning.com/forum/topics/what-circuit-for-computer

Here is a picture of the ASIO CONTROL SETTINGS
for the BEHRINGER UCA222: http://screencloud.net/v/teQ5
NOTE: Morse Keyer does not have an ASIO CONTROL tab so
you have to use another program that does, so that you can bring
up the Behringer's ASIO CONTROL and set it to "FAST" to lower
the latency as much as possible. There are two faster settings
than FAST, but on my computer they did not work.
I was able to use PEDALBOARD2 to bring up the ASIO control
for the BEHRINGER: http://www.niallmoody.com/apps/pedalboard2
HERE IS THE ASIO CONTROL SCREENSHOT USING PEDALBOARD2:
http://screencloud.net/v/w2uC

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