Cw help


Steve <kd5sbp@...>
 

I am having an issue with cw settings I am using wind 8.1,signalink USB  into an alinco dx8srt  also wkmini keyer,keyed, thru all settings still getting  garbage on decode see screen shot  need some advice 




may the God and Goddess grant you peace and tranquility all of you days


Bob McGraw - K4TAX <rmcgraw@...>
 

The FLDIGI CW decoder is about an average performing decoder.  I've tried CWGET, HRD, DX-40, and a couple of others.  The real issue lies more in the quality of the CW signal received.  Now quality includes signal strength, signal-to-noise ratio, and more importantly, the quality of the generated CW.  I find that computer-generated CW, is best in as much as the length of the dits and dahs as well as the spacing is very important.  Next, is CW sent with a keyer, although the spacing between letters will often confuse the decoder.  At least the dits and dahs are the correct lengths.   And last is hand key sent CW unless the operator is darn near perfect with his element length and spacing.  

Good luck.  

73
Bob, K4TAX


Tom - K5EIS
 

I recommend practicing your rig & software adjustments while copying W1AW Morse code practice or bulletins so you know the objective speed and the W1AW signal can be clear of QRM and QSB at times. But don't expect computer software to translate CW without errors. This is due to QRM, QRN, QSB, error in length of the dits and dahs being sent, proper symbol spacing being sent, and the sending speed may vary. A decent CW translation software I've found at http://www.polar-electric.com/Morse/MRP40-EN/ which has a free download & trial, but charges for its use after the free trial. I have no experience with the electronic code readers, but I would expect they would not perform any better. Without a doubt, the best CW translator that I have found is the one between our ears, our brain. Wish I had better information for you. Good luck es 73.


Bob McGraw - K4TAX <rmcgraw@...>
 

I agree with Tom on this.   Oh, I meant MPR-40 and not DX-40.......which is my old CW rig. 

73
Bob, K4TAX


Ed W3NR
 

Change the -25 and 70 to -10 and 70 for a start. What do you have your filter set to ?? Turn your RF gain back some. Looks to me that you have your gain maxed out.

Ed W3NR


Steve <kd5sbp@...>
 

Ed my rig is an alinco dx8srt  on display on radio rf is lowest  -20  filter is narrow 

may the God and Goddess grant you peace and tranquility all of you days

On Tue, Jun 1, 2021 at 10:27, Ed W3NR
<autek@...> wrote:
Change the -25 and 70 to -10 and 70 for a start. What do you have your filter set to ?? Turn your RF gain back some. Looks to me that you have your gain maxed out.

Ed W3NR






Ed W3NR
 

Fldigi does not display RF gain, you need to have rig control to control rf gain. Now you are seriously over driving the sound card input. I suggested -10 and 70 to start.

Ed W3NR


Steve <kd5sbp@...>
 



Ed I was referring to my display on radio  see pic

may the God and Goddess grant you peace and tranquility all of you days

On Tue, Jun 1, 2021 at 11:58, Ed W3NR
<autek@...> wrote:
Fldigi  does not display RF gain, you need to have rig control to control rf gain. Now you are seriously over driving the sound card input. I suggested -10 and 70 to start.

Ed W3NR






Kevin Woods VE7KHI
 

One thing I see is that the squelch function seems not to be turned on.  It filters the gibberish that your fldigi is otherwise required to 'interpret'.

Set sql  to ON  and set the level such that only the Sent Code that you want to hear,  is interpreted by fldigi as Heard Code.  Anything below the level you set will be ignored.  It's a bit of a dance!

That may blow away much of the "chaff".


K3EUI Barry
 

 A few comments on sending/receiving CW  with FLDIGI

1)  The waterfall display settings  (-25, 70) only affect what you see on the FLDIGI waterfall.
    They do NOT alter what the sound card hears for CW decoding.
   The waterfall is only a visual aid.

2) Try turning OFF  the  AFC  option  (lower right) and see if that helps put proper print on screen.
   I notice AFC on some other digital modes often keeps "searching" for the center, wanders off the sender's frequency, and can't find its way back.  That reminds me of when I search for my car in a parking lot and I can't remember where I parked!  What is my search algorithm?

3) Try copying W1AW  CW bulletins at night.
    When I tune in to  3581.5 at night (over S9) FLDIGI copies nearly 100% at all speeds.

Experiment with changing the radio's  IF filter bandwidth. Don't make it too narrow.
Let FLDGI sound card do the "filtering".

I also find that FLDIGI copies just as well when my radio is in USB mode, not CW.
Of course, FLDIGI is in CW mode.
The pitch may change a bit compared to the CW offset pitch of 400-700 Hz.
So just move your VFO up/down a bit to "center the audio" where you want it.
When I operate CW but with radio in USB mode, I try to keep the pitch set to about 1000 Hz on the FLDIGI wterfall
Surprisingly, if I keep the ALC to zero when I transmit, I can send perfect CW by keying the AUDIO in the sound card with my keyboard, and with my rig in USB mode.  The receiving station of course does not know this, nor cares HOW I generate the dits/dahs.

Writing software to decode CW must be difficult, since the noise comes in pulses, especially on 80m.
Does setting the "noise reduction" digital filter to ON help any with CW?

I've had no problems with CW on any of my Icom rigs with rig in CW or USB.
I also set the sound level input to around  -20dB  

de  k3eui
Barry


K3EUI Barry
 

Oh...  one more observation.

Why is the rig set to a VFO dial frequency of   14.000000 MHz ?
Any CW signal puts you OUT of the ham band lower edge

de  k3eui


Steve <kd5sbp@...>
 


Barry  just took picture of rig and I'm authorized to operate outside band as a Mars station  
may the God and Goddess grant you peace and tranquility all of you days

On Wed, Jun 2, 2021 at 7:20, K3EUI Barry
<k3euibarry@...> wrote:
Oh...  one more observation.

Why is the rig set to a VFO dial frequency of   14.000000 MHz ?
Any CW signal puts you OUT of the ham band lower edge

de  k3eui


Mel Marcus <melm@...>
 

interesting question if at 14000 and you operate CW-U you would still be legal  , correct?

Mel 
NE9A

From: winfldigi@groups.io <winfldigi@groups.io> on behalf of K3EUI Barry via groups.io <k3euibarry@...>
Sent: Wednesday, June 2, 2021 7:20 AM
To: winfldigi@groups.io <winfldigi@groups.io>
Subject: Re: [winfldigi] Cw help
 
Oh...  one more observation.

Why is the rig set to a VFO dial frequency of   14.000000 MHz ?
Any CW signal puts you OUT of the ham band lower edge

de  k3eui


Dave
 

CW is an amplitude modulated signal with sidebands that extend out below and above the carrier.  The shape and power density of the sidebands is a function of keying speed and keying waveshape.  This is what the spectrum of a 20 WPM CW signal with a 4 msec rise and fall time looks like:



To insure that no lower sideband energy greater than 30 dB below the carrier was outside of the band edge you would have to put the carrier about 100 Hertz about the band edge, 14000.100.

73, David, W1HKJ

On 6/2/21 9:35 AM, Mel Marcus wrote:

interesting question if at 14000 and you operate CW-U you would still be legal  , correct?

Mel 
NE9A

From: winfldigi@groups.io <winfldigi@groups.io> on behalf of K3EUI Barry via groups.io <k3euibarry@...>
Sent: Wednesday, June 2, 2021 7:20 AM
To: winfldigi@groups.io <winfldigi@groups.io>
Subject: Re: [winfldigi] Cw help
 
Oh...  one more observation.

Why is the rig set to a VFO dial frequency of   14.000000 MHz ?
Any CW signal puts you OUT of the ham band lower edge

de  k3eui


 

In most new rigs, the dial frequency is the actual frequency on transmit if you are using either CW-L or CW-U – the rig takes care of the audio tone and mode when calculating dial frequency. If you are using USB or USB-D with MCW (keyed audio) then the actual frequency is dial frequency plus your audio frequency.

 

73 Phil GM3ZZA

 

Sent from Mail for Windows 10

 

From: Mel Marcus
Sent: 02 June 2021 15:35
To: winfldigi@groups.io
Subject: Re: [winfldigi] Cw help

 

interesting question if at 14000 and you operate CW-U you would still be legal  , correct?

 

Mel 

NE9A

From: winfldigi@groups.io <winfldigi@groups.io> on behalf of K3EUI Barry via groups.io <k3euibarry@...>
Sent: Wednesday, June 2, 2021 7:20 AM
To: winfldigi@groups.io <winfldigi@groups.io>
Subject: Re: [winfldigi] Cw help

 

Oh...  one more observation.

Why is the rig set to a VFO dial frequency of   14.000000 MHz ?
Any CW signal puts you OUT of the ham band lower edge

de  k3eui

 


K3EUI Barry
 

Yes.  Thank you.
On some newer rigs, the pitch does not change if you switch from CW mode to USB or USB-D mode.


Remember, you can listen to CW with the rig in CW mode, the way we would expect to.
You tune the VFO to the transmitting frequency  (3581.5 kHz for the W1AW CW bulletins).
That is the frequency they are broadcasting on.
This is more critical if you have a narrow filter (250 Hz).
Now, internally the radio has a  BFO  (beat frequency oscillator) which mixes with the RF signal and produces the audio tone.  Old radios had a  BFO adjust knob. Newer radios have a  "PITCH' adjustment or MENU. Most pick 400 to 700 Hz as a comfortable listening pitch.  Of course, FLDIGI does not care, as long as you center the cursor in the waterfall on the pitch of the sender.

The  CW-U  or  CW-L  only refers to the choice of the BFO frequency.  You can produce the same audio pitch CW by placing the BFO 700 Hz below the RF or  700 Hz above the RF wave.
In both cases, the CW you hear is at an audio pitch of  700 Hz.
The difference is that one setting may eliminate a nearby QRM signal from another ham.
Even with the older rigs, I could just turn the BFO knob and accomplish the same result.
The transmitting RF frequency is your VFO dial freq in CW mode, or, as mentioned, the VFO + the audio pitch if your rig is in USB.  Or  VFO - audio pitch if in Lower Sidebanc.
It is very easy to "zero beat" a station calling CQ.  Just click on his signal trace in the FLDIGI waterfall.
In either LSB or USB, you must be on his/her frequency.

Back to why FLDIGI struggles to put perfect print on the Rx window.
There could be many reasons, but most likely it is that the sender is not sending perfectly timed CW notes. When I listen to bugs (the old mechanical keyers) I oten hear the "dahs" being much longer in duration than  three "dits".
It sounds kind of like a slang.  I understand it, but FLDIGI gets confused.

It can be even worse when the CW spacing between letters and words is say 10 wpm, and the individual dits and dahs are at about 20 wpm.  My brain adjusts.  FLDIGI does not.
If FLGIDI  gets the V V V  correctly, I know I am in good shape to demodulate.

Although I can and often have CW QSO's with my rig in USB (or LSB) mode and key the AUDIO via FLDIGI, and send with my keyboard, not a physical key, I would not call that  MCW  (modulated CW) since the rig eliminates the carrier and "other" sideband.
That is, I call the sending mode  MCW when the rradio does not need a BFO, or when the mode I am sending CW has a carrier with superimposed audio modulation.
Said another way, for it to be called MCW, my rig must be in either AM or FM, since both have a carrier.

Keyed audio into a SSB rig does not produce MCW.
It is just CW, generated a different way from keying an oscillator or buffer.
On a scope, you can't tell HOW I generated CW in my transmitter.
Your ears can't tell either.
Both methods are legal.
Just be careful your audio does not overdrive you SSB radio -  same advice as when you are on phone with a microphone.  NEVER use compression when operating CW in SSB mode.

Oh...  and I never turn on the FLDIGI squelch when operating CW and want to use the Rx window as a kind of backup.  Squelch might distort the sound.

de  K3eui  Barry