The Calf-Studio Software Morse Code CW KEYER - brief demo using Straight Key, Paddles & CW Keyboard

using the free LV2 apps from:

a software CW KEYER is constructed by chaining the apps together in an array that does the following...

1. a sidetone from the internal or external ports is routed first to the CALF EQUALIZER 5 BAND LV2 PLUGIN where the 1khz sidetone from the K1EL, the HEATHKIT CPO, or the YPLog audio output is filtered as shown on the video to create a 1khz bandpass/peak filter...this allows you to use any kind of sidetone, even a rough raspy sidetone,(like the output from the K40 cw keyer or the HEATHKIT CPO, so you can use a sidetone from any source, and the CALF STUDIO CW KEYER system will only use that "not so wonderful" keyer sidetone, even the worst ROUGH RASPY SIDETONE, to "key" the CALF-STUDIO software CW KEYER setup...

2. from the output of the CALF EQUALIZER 5 BAND the sidetone is routed to the 2nd channel input of the CALF GATE....on the first channel input of the CALF GATE is a PURE SINE WAVE GENERATOR that is always ON at a specific volume....the CALF GATE holds it back though, until the GATE is triggered by a sidetone on the CALF GATE INPUT PORT 2 channel...the GATE settings, setup as shown, allow for a very accurate "CLONE" of the original sidetone element length from the ST KEY, the PADDLES, the k1el K40 KB or the YPLog cw keyboard...once triggered, the GATE will pass the pure wave tone that is already waiting on CHANNEL ONE....through the channel one gate to its output...then...that "channel 1" pure sine wave audio will pass through 3 CALF FILTERS.... HIGH PASS, LOW PASS, and finally the CALF BANDPASS filter...this puts a very well constructed "edge" on the rise and fall time of the PURE WAVE TONE after it leaves the CALF GATE(NOTE: out of the GATE - the pure sine wave tone has zero rise/fall time with key clicks on the CALF FILTERS take out all the edge noise and produce a smooth rise and fall time on the note)... you may observe on the SCOPE & the SPEC AN, the final CW NOTE is very clean and sounds like what you would normally hear from a raised cosine cw note with about 8 ms of rise/fall time on it.... the CALF-STUDIO software CW KEYER can be adjusted to your preference for PITCH, WEIGHT, VOLUME, harder or software adjusting the settings on the CALF-STUDIO APPs

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Comment by Chuck aa0hw on February 14, 2018 at 3:09pm

Here is another way of building your own software CW KEYER on Linux using LADSPA PLugins:

brief demo of using Alsa Modular Synth and some LADSPA plugins to build a Morse Code software CW KEYER...that can be "keyed" externally by paddles, st key, bug, kb...etc... or it also can be "keyed" internally by another CW KEYER software APP like FLdigi...

EXTERNAL CW KEYER SETUP: using a CW KEYER to "key" a 555 timer chip putting out a 1khz square wave....the 555 chip's cw audio tones are connected to a laptop's MIC INPUT....inside the LAPTOP's audio engine//JackRouter connection bay....that 555 audio is wired over to the SIDECHAIN input of the ZamGate LADSPA Plugin....ZamGate settings are adjusted accordingly to trigger a pure sine wave tone on the AUDIO INPUT Port 1 of ZAMGATE....ZamGate holds off the pure sine wave sidetone until the SIDECHAIN port is triggered by set amount of audio volume from a 1khz tone from the paddles/555 or internally by a cw keyer like FLdigi(using FLdigi QSK MODE RT channel 1khz tone output) ZamGate shapes the WAVE OUT by putting a 4.5 millisecond rise/fall time onto it before it leaves the optional VARIABLE STATE FILTER LADSPA PLUGIN is used to filter the edges to approach a raised cosine level of CW NOTE wave shape


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