All Blog Posts (232)

CW Copy Practice using a CW MIDI file & a variable speed MIDI player with The AD5DZ CW Keyer

brief demo using REAPER as a variable sped CW MIDI FILE PLAYER ...sending a text file that has been converted to a CW MIDI file by a CW TEXT to MIDI converter like Morse Midi or ehoCW

the VARIABLE SPEED on REAPER is excellent and the timing is very accurate at any speed you dial in

the AD5DZ CW KEYER has many CW parameter adjustments,…


Added by Chuck aa0hw on April 22, 2020 at 7:52am — No Comments

QSO QRQ CW using 17 Khz CW VLF RF over ip by a Gstreamer OPUS CODEC script to a Remote VLF TX antenna

Experimental Morse Code QRQ CW setup over ip to send VLF RF CW at 17Khz using the OPUS AUDIO CODEC - to a remote TRANSMIT ANTENNA located at the other OP's QTH... the other OP receives the VLF TX RF using a small FERRITE BOBBIN CORE INDUCTOR COIL antenna hooked directly to their PC Mic or Line, soundcard input

the 17Khz CW TX/RX by the…


Added by Chuck aa0hw on April 21, 2020 at 10:00am — No Comments

QUISK SDR APP for CW QSO on MUMBLE iCW Server - CW at 10 Khz VLF RF over IP - several advantages

the QUISK SDR APP provides several useful functions for conducting CW QSO's over ip at VLF RF(10Khz) on the iCW MUMBLE SERVER:

1. QUISK has Tx/Rx RIT - you can…


Added by Chuck aa0hw on April 16, 2020 at 10:58am — No Comments

QRQ CW on The Dreamer's Band - VLF(sub 9 Khz) - LIVE demo

brief demo to test 7.373 Khz QRQ CW Transmit/Receive

on the VLF "Dreamer's" BAND:



Added by Chuck aa0hw on April 9, 2020 at 2:27pm — No Comments

QRQ CW Copy by Ear Practice - 11 CW Signals - speeds from 61 - 81 wpm - use an SDR APP to choose & listen

There are 11 CW signals to choose from,

each one at a different speed from 61 wpm to 81 wpm.

Use your own SDR APP on your own PC to scan each signal and choose the speed you would like to use for COPY BY EAR practice.

Use a Virtual audio cable as the YouTube browser playback device and set your SDR input to use the same…


Added by Chuck aa0hw on April 6, 2020 at 11:02am — No Comments

VLF-LF QRQ CW RF over ip - using an experimental REMOTE VLF-LF BAND Transmitter-Receiver server setup

brief demo of a REMOTE VLF-LF band transmitter/receiver with 9 QRQ CW ops present and sending CW

More details about the REMOTE VLF TRANSMITTER - REMOTE VLF ANTENNA here on playlist:…


Added by Chuck aa0hw on March 18, 2020 at 2:43pm — No Comments

20 Watt VLF QRQ CW transmitter(18.200 Khz) - AD5DZ CW Keyer, Audio Amp, 4 to 1 Balun, Delta Loop

Brief experimental setup using the AD5DZ CW KEYER, to directly send 18.200 Khz CW AUDIO to a 20 watt audio amp...from the audio amp output to a large BLUE IRON POWDER TOROID 4 to 1 balun - then to the input of a compact 21 foot long DELTA LOOP wire antenna with one leg of the delta loop connected to a series resonant capacitor(6uF)

This 4…


Added by Chuck aa0hw on February 20, 2020 at 4:44pm — No Comments

Narrow Band QRQ CW filter, 50 hz wide, 2 APP combo to get rid of ringing & howling - 50 wpm test

this is an experimental test setup to get rid of narrow band CW filter SEA SHELL BACKGROUND HOWLING, and QRQ CW Ringing...

by using a:



the gate silences the "in between" cw element sea shell howling, and ringing, but also causes key clicks...

the following CW BANDPASS…


Added by Chuck aa0hw on February 18, 2020 at 12:16pm — No Comments

VLF Transmitter(delta loop) - VLF Receiver(Ferrite Core Bipolar Tesla Coil) - QRQ CW demo

brief demo of testing a VLF TRANSMITTER and VLF RECEIVER for QRQ CW operations

this is a follow up video to the first two using a VLF RECEIVE - BIPOLAR TESLA COIL with a FERRITE CORE antenna...the Transmitter is a tiny DELTA LOOP(7 foot per side) fed by a 5 watt audio amp…


Added by Chuck aa0hw on February 16, 2020 at 2:19pm — No Comments

Windows 10 laptop, transmitting @ 8 Khz on VLF band, QRQ CW @80 wpm - Received on Linux Laptop using SAQrx SDR RCVR

this is a follow up video to the first one:

everything is the same in this video, except, this time we send QRQ CW at 80 wpm to test how it will sound over VLF and using SAQrx by itself - using its 300 hz wide bandpass filter - centered at 700 hz

and with…


Added by Chuck aa0hw on February 14, 2020 at 12:43pm — 1 Comment

Receiving a QRQ CW signal on VLF using QUISK SDR and wire antenna attached to sound card input

brief demo showing QUISK SDR and a wire antenna hooked up to the PC's sound card input
- picking up a weak QRQ CW signal on VLF - 18 khz

- by using the AGC on QUISK SDR and sending the QUISK SDR receive audio through the CALF EQ 5 BAND lv2 plugin, the weak signal is brought up significantly to improve copy

Added by Chuck aa0hw on February 12, 2020 at 3:25pm — No Comments

QRQ CW LAB - Testing a REMOTE RIG CW KEYING setup using a Raspberry PI::Rig interface

REMOTE RIG QRQ CW KEYING - over ip - using Gstreamer scripts on a Raspberry PI 2b::RIG hardware interface, and a remote OP's Linux laptop, on the local area network, wired Ethernet, going through a Router and network switches


ROUTER = 20 yr old router, 100 mb limit...

ETHERNET CABLES = two "CAT 4" - 100…


Added by Chuck aa0hw on February 8, 2020 at 3:30pm — No Comments

Gstreamer 1 line of code to produce a 2 tiered, 2 tone, final bandpass filter for CW & PTT - AFCW - QRQ CW demo

brief demo of QRQ CW testing a Gstreamer CLI 1 liner - to get two different audio bandpass filters at the same time, staggered, and incremental, for their respective tones of 707 hz and 5555 hz



gst-launch-1.0 -v interleave…


Added by Chuck aa0hw on February 4, 2020 at 2:38pm — No Comments

Remote QRQ CW over ip operations using multipurpose Gstreamer Scripts - laptop to Raspberry PI::RIG interface

Several Gstreamer scripts are used to perform REMOTE QRQ CW KEYING of a RIG(afcw mode) from the REMOTE OP's location using TCP audio over ip network packets through a router and network switches in the pathway(WIRED ETHERNET)

there are 2 Gstreamer BANDPASS filters applied before audio goes to rig for transmit:

1. 680 hz BPF Gstreamer…


Added by Chuck aa0hw on February 3, 2020 at 1:20pm — No Comments

Get better audio quality from the Elecraft K3S QRQ CW SIDETONE MONITOR - using the Noise-Repellent plugin

An lv2 plugin for broadband noise reduction

brief demo showing how noisy the ELECRAFT K3S transmit audio input monitor circuit is....and how well the Noise-Repellent LV2 Plugin takes out virtually all of that K3S background noise,…


Added by Chuck aa0hw on February 3, 2020 at 10:44am — No Comments

QRQ CW remote Keying a RIG(afcw) at 80 wpm using Gstreamer RTSP server::client scripts - full test run LIVE demo


Gstreamer has its own RTSP server::client scripts...

Gstreamer also has a way to interleave and deinterleave a 2 channel audio order to apply a different tone to each channel for transmit and then de-interleave them at the destination location and... just before going into the RIG's LINE INPUT For TRANSMIT, Gstreamer has…


Added by Chuck aa0hw on January 31, 2020 at 2:59pm — No Comments

QRQ CW audio OVER ip test - 24 bit VS 32 bit - uncompressed audio over Ethernet

brief test of 24 bit VS 32 bit uncompressed audio going from a laptop to a Raspberry pi 2b loopback - and then right back to the laptop over Ethernet cables going through router and switches

32 bit has virtual no variance from the original audio source

24 bit does show a wide berth of harmonics generated at the lowest db…


Added by Chuck aa0hw on January 26, 2020 at 7:39am — No Comments

Elecraft K3 dead spots in the FULL QSK RECEIVE AUDIO when operating QRQ CW mode

NOTICE the DEAD ZONE in the following SCOPE view of sending a couple of 55 ms DITs... while trying to listen for how much QSK RECEIVE AUDIO is between those dits....NOTE:  you will see a GAP of "NO AUDIO" from phase cancellation due to the technique that the K3 firmware uses to try and get "more" QSK audio for the QRQ OP's 

the steady…


Added by Chuck aa0hw on January 25, 2020 at 3:56pm — No Comments

Gstreamer "audio OVER ip" for HAM RADIO - audiointerleave/deinterleave plugin examples for QRQ CW Remote Rig Operations

this video demoS using GSTREAMER's audiointerleave and deinterleave plugins for a Gstreamer OPUS CODEC AUDIO OVER IP remote rig audio operations use...


break the 2 channel audio over ip pipelines into 2 individual pathways that can contain their own individual Gstreamer audio DSP plugins...

in this case....2 different…


Added by Chuck aa0hw on January 23, 2020 at 11:15am — 1 Comment

QRQ'n with the K1EL K40 CW Keyer(60 - 120 wpm) using a CW Keyer audio to EMF COIL PC interface

this is a follow up video to this one:

the K1EL K40 CW KEYER's SPEAKER AUDIO OUTPUT is hooked directly to the Ferrite Bobbin Core Inductor Coil EMF PICKUP COIL is right on top of the COIL(cheap telephone recording emf pickup coil)...connect the EMF…


Added by Chuck aa0hw on January 20, 2020 at 3:00pm — No Comments

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