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: 205

Comment by Chuck aa0hw on August 9, 2018 at 11:13am

Here is the AD5DZ software CW KEYBOARD sending at 151 wpm and its controls adjusted to try and make the copy by ear at this speed, a little bit easier - with all the options the AD5DZ software CW  Keyboard has to offer:

This video will demo the AD5DZ at an extreme QRQ CW sending speed = 151 wpm

some of the cw timing controls will be adjusted during the text file sending - you many notice that a tiny change can make a slight difference in how the cw sounds at this high speed....

headphones may be necessary in order to hear the subtle changes in the cw audio

the controls I thought that gave the most benefit for making copy by ear at this speed a little bit easier were:
1. the 2nd window selection
2. the compensation - trimming off just a tiny bit of time off of each cw element equally
3. the weight and ratio also provided some help
4. the amount of rise/fall time - “ramp” which adjusts both rise/fall time the same amount
5. cw pitch - a certain pitch seems to have been easier to copy by ear at this speed

here are the settings that seemed to help me the best at this speed to copy by ear a little better…
WINDOWs 1. cosine 2. gaussian
PITCH 885 hertz
WEIGHT 45.1 %
RATIO 43.3 %
RAMP 5.6 ms rise/fall time
the HP/LP/BP filter i found to be another great help to bring down further - the remaining cw element edge noise after adjusting the cw keyboard controls



You need to be a member of QRQcw to add comments!

Join QRQcw

Please consider making a donation today to help us pay for this website and keep QRQcw alive and growing

We have received  $0 of the $250 needed for the Ning website fee due 8-1-2019



© 2018   Created by Chuck aa0hw.   Powered by

Badges  |  Report an Issue  |  Terms of Service


Live Video