QRQ CW over 100 wpm - tips, techniques and specialized QRQcw GEAR

This video is demo’N a setup to create a custom QRQ CW sine wave, raised cosine edged, ‘keyable’ oscillator

There are already 2 excellent programs for LINUX for a software QRQ CW KEYBOARD… FLdigi and TWQRQ...however, neither one of them are ‘keyable’ - this first video in a new video series on “QRQ CW OVER 100 WPM” uses Fldigi as a tool to build a new software QRQ CW pure sine wave, raised cosine edged, ‘keyable’ oscillator...that you can adjust weight both by TIME and by PERCENTAGE…you can also choose the raised cosine ‘window’, adjust pitch, volume, Q, bandwidth etc… NOTE: at QRQ CW over 100 wpm, many of the cw element parameters become critical for good copy… for example, the edge noise, in spite of the cw element having an 8 ms rise and fall time, increases with cw speed and must be reduced...the edge noise can get so loud as to be 50 percent of what you hear… the VSTs filter it out very well...

NOTE: headphones might be needed in order to hear the subtle cw edge changes
NOTE: only one speaker output is used for the video, to prevent 2 speaker phase issues while listening....you can use a STEREO to MONO adapter if you need to hear this video on both speakers..

first a 1000 hertz tone from Fldigi’s RT QSK CONTROL RT CHANNEL audio output goes to the input of the VST HOST’s first VST PLUGIN, a bandpass filter...which is centered at 1000 hertz...the volume of its output is CRITICAL to get the weight by TIME to work in the following plugins… [ - 1.74 db in this setup ]

the bandpass filter connects to the first REAGATE VST Plugin, where again the threshold volume(-.2 db) is critical to get the weight by TIME to work on the next plugin...another REAGATE…

the 2nd REAGATE PLUGIN is used for adjusting the WEIGHT BY TIME on the CW NOTE...the threshold slider in the middle is set to clone Fldigi’s weight and if you raise the threshold slider higher...you get lighter keying...if you lower the threshold slider you get heavier keying…

the next VST PLUGIN is called “sineCW” and is the heart of the system...where the 1000 hertz tone is used to create a new “cloned” cw element..sineCW lets you adjust the CW PITCH, VOLUME, bandpass filter bandwidth and Q, and rise/fall time

the final vst plugin is called the ENGINEERs FILTER, where we remove any remaining edge noise and select the filter ‘window’ to your preference...each window sounds a bit different...and allows more or less edge noise to get through to the audio output…

a text file from TOM’s, W4BQF, article about copying CW OVER 70 wpm is used...and demoN some of plugins while sending...


Views: 63

Comment by Chuck aa0hw on February 7, 2018 at 11:14am

Here is a good demo of transmitting QRQ CW at 150 wpm on an Elecraft K3S using AFCW mode and the WA0EIR TWQRQ's "Hamming" Raised Cosine wave shape:

This video briefly demo's a setup using a raspberry pi 2b to key an Elecraft k3s at 150 wpm using the wa0eir "TWQRQ" CW KEYBOARD...the TWQRQ "HAMMING" RAISED COSINE wave shape is chosen to transmit every cw element using the K3S in AFCW MODE - sending an audio cw tone out on LOWER SIDE BAND...(u must be careful to not activate the rig's ALC circuit or harmonic generation and other audio artifacts will also be transmitted...a pure sine wave with lots of smooth edge shaping is utilized to provide a very clean CW NOTE RF signal on HF)

NOTE: all RF from the K3S on this video was going only to a 50 ohm dummy load

the RIG's VOICE VOX circuit is used to activate the PTT...for transmission of the cw audio tones from the RASPBERRY PI/TWQRQ CW KEYBOARD....however, the first 20 milliseconds will get chopped every time the PTT is reset after a pause in sending(semi QSK)...to prevent this, a SUB TONE at 33 hertz is sent ahead of the actual CW TONE(828 hertz) to activate the PTT first, before the CW NOTE arrives at the K3S LINE INPUT....for transmission on LSB(a2 mode) it was found by testing, that it takes about 30 milliseconds of delay of the cw note, to keep it from being chopped off by the K3S VOX CIRCUITs....the K3S VOX DELAY is set to preference for HANG TIME / semi-qsk

- one demo on this video - is sending a dit at 150 wpm and then the delay line is turned on and off to demo that the dit is being successfully sent and fully intact(if 30 ms is used) or not being sent at all(if zero milliseconds is used)

NOTE: the 33 hertz sub tone is at such a low volume and low frequency, that it is rejected by the K3S, and does not get transmitted by the K3S TRANSMIT CIRCUITS...but the 33 hertz tone is still useful to activate the K3S PTT CIRCUIT(at 33 hertz and minus 23 db's of volume)...NOTE: the 33 hertz audio is filtered out of the K3S sidetone MONITOR transmit audio circuits by using a CALF FILTER(LV2 Plugin) in "band rejection" mode, so you do not hear any 33 hertz tone while monitoring the sidetone on the K3S...

for more info or to request a copy of the latest version of TWQRQ, please contact the TWQRQ creator, WA0EIR, via email...

NOTE: by using the AFCW CW TRANSMIT mode, it is possible to key QRQ CW on the K3S over 100 wpm(since by itself, the K3S transmits CW very poorly above 100 wpm)

Comment by Chuck aa0hw on February 12, 2018 at 8:52am

Use the ZamGate CW Keyer for better QRQ CW audio when training on FABIAN's Learn CW online

Brief demo of using the ZamGate CW Keyer's CW OUTPUT instead of the default website audio from Fabian's Learn CW Online QRQ CW training website...https://lcwo.net/plaintext

the ZamGate CW Keyer will help you to get better audio for copy by ear training .. the ZamGate CW Keyer can be adjusted for a customized rise and fall time and weight, to help eliminate as much of the QRQ CW element edge noise as preferred, adjust the cw pitch and volume on the fly...and make the cw keying as hard or soft as you might find useful for improving the qrq cw audio tones for your copy by ear QRQ CW training...especially above 120 wpm to 130 wpm high speed Morse code...where the edge noise starts to be almost as loud as the actual cw tone - if the edge noise is not filtered out...

Comment by Chuck aa0hw on February 13, 2018 at 3:54pm

Here is a video demo using FLdigi's RT QSK CONTROL to adjust "cw element weight by time" for QRQ CW being sent at speeds above 100 wpm:

Being able to adjust "weight by time" in tiny increments; i find to be very effective at improving the "sound" and clarity of QRQ CW tones being sent at speeds above 100 wpm..."weight by time" sounds different than "weight by percentage"(the usual type of weight control in cw keyers)

to homebrew a "WEIGHT BY TIME" setup....FLdigi's RT QSK 1 KHZ TONE is used to "key" another CW KEYER - The "sineCW" a VST PLUGIN

this video demo's the setup at 111 words per minute speed from FLDigi sending a text file ...then the FLdigi "RT QSK" control is used for coarse adjustment of the "weight by time" and the FLdigi "EDGE TIMING" control is used for fine adjustment of the "weight by time"
(.5 to .1 millisecond increments for COARSE and FINE)

the Mbandpass filter is demoD and turned ON and OFF to show how effective it is at eliminating virtual all of the qrn // qrm from cw element edge noise, where above 100 wpm, the cw element edge noise can get quite loud and distracting...and can almost be as loud as the actual cw tone...

the usual CW REGENERATION VST PATHway is used as shown in many previous videos...REAGATE(which performs audio to cw midi conversion...a midi message is created and transmitted to the sineCW keyer...sineCW makes a very well constructed cw note with adjustable pitch, volume, bandpass filtering, rise/fall time, TONE(SINE,SQUARE,TRIANGLE...etc) and raised cosine waveshape (Linear/exponential/ etc...)(i find the EXPONENTIAL raised cosine edges from sineCW to have a slightly "better" sound above 100 wpm)

You can of course also adjust the typical FLdigi controls for weight by percentage AND dot/dash ratio....and combing all these standard options with the "new ones" as shown in this video... makes for a very versatile QRQ CW STUDIO for high fidelity, high quality CW AUDIO TONE listening...


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