How to / Can the "mechanical / metal clacking " be filtered from this video's audio track?
mstram
Posts: 49
I'd like to remove as much as the "mechanical /metal clacking" as possible from
this video's audio track, leaving only the "morse tone", which is ~780hz
I have Audacity and Goldwave, any other program suggestions are welcome.
I tried messing with Audacity's "noise reduction" effect, and had some limited success,
but as an Audacity newbie, I'm thinking there might be better techniques ?
this video's audio track, leaving only the "morse tone", which is ~780hz
I have Audacity and Goldwave, any other program suggestions are welcome.
I tried messing with Audacity's "noise reduction" effect, and had some limited success,
but as an Audacity newbie, I'm thinking there might be better techniques ?
Comments
No, Alicia Silverstone is the ditz.
No, that's mechanical noise from the keyer. the high pitched tones are the dits.
Check out the frequency counter at the top of the center rack.
An old friend of my was really into Morse. One time his wife complained that he was tapping out Morse on the side of the bed whilst he was dreaming.
A few years back I was dosing off in front of the TV only to be woken by the sound of ... --- ... coming from the TV, then a bunch of Morse code. Turned out this is part of some national emergency system in Finland. They were alerting us that a bear had walked out of the forest into a town some hundreds of kilometers away.
A bit later I was woken up by more Morse from the TV. The all clear. The bear had been shot. Phew, now I can get some sleep. Poor bear.
Not that I was ever very good at Morse.
Yup, second think we learned.
It was/is created by Justin Frankel, the creator of WinAmp who then sold it to AOL for like $millions. Free for 60 days and if you don't license it, it keeps working without restrictions anyway. At least this used to be true. I am a licensed user.
For some reason the notch filter didn't work at all, but when I manually "drew" the envelope in the equalizer I got decent results.
I also downloaded an "ultra narrow" filter from the Audacity forums which gave similar results to the equalizer
@xanadu :
@xanadu, I'm a beginner at morse, I've found a few good programs to learn it.
1) http://morsecode.scphillips.com/translator.html
Change the settings to 20 wpm 700 hz
Type in cq cq cq de .. then I'm not sure .. sounds like TAPH/TST or TAPHTST
Change the speed down to about 10 or 12, and space out the letters "C Q", you should start
to hear the patterns.
This is free neat program that lets you simualate *sending* morse using either your keyboard (down arrow)
or mouse lmb/rmb (with the mouse can use iambic keying).
http://www.mrx.com.au/d_cwcom.htm cwcom - can send with down arrow or mouse
This is another good free program that will *read* incoming morse tones on your soundcard, as well
as let you send ("text-to-morse typed in)
http://www.qsl.net/hamscope/
As for the message, it starts out with CQ CQ CQ DE then it sounds to me like either TAPHTST or TAPH/TST ?
This sounds like the punch line to my convoluted brain teaser in the "Speed of Light" thread.
Yup, that wild woman is using a VibroPlex keyer, AKA 'bug'. I enjoyed my WB4VVF AccuKeyer in my formative years.
They're called Iambic keyers. Squeeze one side you get dididididit, squeeze the other you get dahdahdahdah, squeeze both together and you get didahdidahdidah.
Jim
cq cq cq de kph/kfs/ksm nw please join us for the traditional closing message bt
dear goddess the members of the maritime radio historical society are your
humble servants and we thank you for protecting us this past year as we
continued our stewardship of the stations kph and ksm the music of morse has
gladdened the hearts of many as we have crossed the barriers of time and space
we ask your aid and guidance in our decisions and actions during the coming
year that we may be worthy of the equipment and tradition that has been
entrusted into our humble hands
bless also the ears around the world that share
the fruits of our labours zut 73/88 da de kph/kfs/ksm cl
Should you want a pure tone, normaize and compress what is left to get a brick wall.
Then make a file full of the pure tone. Mix using the and function, and it will subtract, leaving you with a very pure tone with hints of the orginal signal.
At that point, it's not original audio anymorr, but it will have the timings and hints of the original in it.
That operator has a distinct timing too, and that's always of interest in most code discussions I've been a part of, as are the little pauses and variances in keying.
The actual transmitted tones are something else.
Denice Stoops is just so cool.
https://www.dropbox.com/s/z0vqn7gkgyoqyds/ph-morse-tones.mp3?dl=0
General approach:
1. Normalize the audio
2. High pass filter, then low pass filter, 48db aggressive. I used 730 and 830Hz as my starting boundaries.
3. Apply notch filter, I used 30hz and the most aggressive settings.
4. Use hard gate and Single Band EQ in order to pass maximized tones and drive the rest toward silent. (Gate limits by dB level)
There is some ringing in it. Turns out I was wrong about the clacks. They do not completely overwhelm the morse tones. I probably could work with the gate more, filters less and get a bit better than what you hear on this one.
Worth doing?
Then they "upgraded" here computer from DOS and WordPerfect, or whatever, to Windows. She was immediately complaining like hell. The machine could not keep up with her typing speed.
A valiant effort. It's also an apt demonstration that frequency and time are conjugate variables. Narrowing the uncertainty in one (narrow-pass filter), increases the uncertainty in the other (ringing). There's no such thing as a free lunch in physics. It's the law!
-Phil
It is indeed the law.
My wife, back in the day, could jam up the ball on an IBM Selectric
Jim
IMHO, the best really would be be a mix down of the product of that second pass, and a file full of a pure tone. Brick wall compress the resulting file, then clip to make basically pure pulses out of it to preserve the timing, and the resulting mix would have the timing and subtle keying dynamics of the operator in it, done with an artificial tone. If one loads the optional Audacity plug-ins, a diode processor is there... Honestly, a lot of pretty good tools for freebies.
I may do it, just for fun. The Aucadity tools are good enough.