CW on AO-100 (Help please)

[G4MWR]

So gentlemen,
I can not find an answer in FAQ's on this issue, so I would like to ask the many users with far more knowledgeable and experience with SDR Console a seemingly simple question.
With both a CW Transmit mode and the ability to generate variable tones, can SDR Console easily be hardwired via my laptop USB port or other, to be "keyed" by my straight key?
Or am I to use an external tone generator with my key and inject the audio into the "Mic in" and use a separate PTT?

Thank you for your time.
Bob G4MWR

[Max]

So gentlemen,
I can not find an answer in FAQ's on this issue, so I would like to ask the many users with far more knowledgeable and experience with SDR Console a seemingly simple question.
With both a CW Transmit mode and the ability to generate variable tones, can SDR Console easily be hardwired via my laptop USB port or other, to be "keyed" by my straight key?
Or am I to use an external tone generator with my key and inject the audio into the "Mic in" and use a separate PTT?

Thank you for your time.
Bob G4MWR

Bob, there will be different solutions depending on your hardware. What is your (or proposed) SDR?

73

Max

[Max]

Bob, there will be different solutions depending on your hardware. What is your (or proposed) SDR?

73

Max

Just re-discovered this thread worth a read through regarding Pluto and Lime for example where you would key, as you said, via SSB audio input. If you have Hermes Lite 2 (like me) then this has a standard CW mode and the TX can be keyed via front panel jack and built in sidetone in SDRC.

https://groups.io/g/SDR-Radio-TestTeam/topic/101813931

The program Morse Keyer that Sigi refers to in the discussion:
https://morse-rss-news.sourceforge.net/
https://morse-rss-news.sourceforge.net/ ... keyer.html

CWType - Donationware but can interface with manual key
https://www.dxsoft.com/en/products/cwtype/

MRP40 (unfortunately it's paid-for and not cheap!). Again can interface with manual key entry
https://www.polar-electric.com/Morse/MRP40-EN/

73 again

Max

[G4MWR]

Hi Max, thanks for the reply. I have the Pluto Plus running SDR Console all up and running. So SSB is fine, no problem, but I would like to migrate my key over for some CW on the lower portion of the bird. I'll spend some time going over the suggested reading you have kindly suggested first and then get back to you. I had hoped there would be a simple soulution rather than Key- tone generator- mic in on USB. Many thanks for quick reply. Bob 73 & VA

[Max]

I had hoped there would be a simple solution rather than Key- tone generator- mic in on USB. Many thanks for quick reply. Bob 73 & VA

Ah, yes, I see. Then sadly from what I have read on here there is no native CW mode for Pluto so the only option is to use one of those softwares to send tone to the audio in using serial port for key input to PC and maybe use VOX as semi break-in keying or of course a footswitch for PTT.

So mostly I suggest read though that forum post I linked and especially the reply from Sigi, DG9BFC. He is the big Pluto expert on here and seems to have got his solution working well.

Good luck and 73

Max

[G4MWR]

Well, at least I know that there isnt an in-built solution and I can go find a tone generator and just patch into the audio input Max. That saves time looking in other posts, forums, FAQ's so thank you, most helpful. Iam 100% on SSB, but for my first QSO on the bird, it must be CW. My last satellite QSO was back in the 80's on OSCAR 10 (432 up - 144 down) and now coming back into the hobby, I thought it only right to start where I started a long time ago! Its a bit of a learning curve........Hi
Hope to speak soon on AO-100. all the best 73s G4MWR

[G4MWR]

Dear Max, I have researched the issue " CW tone on SDR Console" and I have read one or two of the CW related comments, articles and questions raised on the forums and I did go and read the solution you directed me too, Sigi DG9BFC solution.
And the answer is:
"If you do not want to ran a Keyer program on top of SDR Console, then just use a tone generator into the mic input. Albeit, ensure the level is right, make it a sine wave as square waves generate harmonics."
You know, I thought CW would have been easier! ANyway, thanks for the info, help and pointing me in the right direction. Very useful. 73s and Gud DX

[jdow]

Slow speed CW is not all that difficult with general purpose PC input ports. This may be REALLY slow speed, mind you. The basic problem is that PCs have large latency issues on IO. Built in printer ports no longer exist. So you have no help from that parallel port IO we used to enjoy. Of course, even it had problems. Today we generally find yourselves polling status signals on a built in or USB serial port or using a USB GPIO card. These all involve polling cycles on a multi-tasking system. USB has IO latencies on top of this. You are looking at as much as 10ms of latency jitter. I'll leave it as an exercise for the student to determine what CW WPM leads to the possibility of a dit becoming a dah or a dah becoming a dit might be. Needless to say at that CW speed your keying would sound "bad".

You really are better off with audio keyed by your keying tool, straight, bug, whatever. It will come out late, 50 ms or more late. But, the signal will be well formed. Just monitor it off your key rather than off the PC audio or signal monitor. This is rude. It is crude. It is the TAO, the way, at some point beyond the 5-10 WPM regime.

With a fully custom hardware and software setup you can vastly improve on this, in theory.

{^_^}

[Max]

You know, I thought CW would have been easier! ANyway, thanks for the info, help and pointing me in the right direction. Very useful. 73s and Gud DX

Yes, I thought the same as you when I first came to this, but then it soon dawned that where any digital system is concerned, then straight away you are fighting latency, and when millisecond timing is concerned (as in CW) it soon causes issues, so it's back to basics. Simon has done a sterling job with the built-in sidetone in SDRC for the Hermes Lite 2 but part of that is because HL2 has a CW mode built in as native, so it can be truly "keyed". Not many of the other SDRs used routinely with SDRC have that luxury.

Even so, there is still a very small latency that is beginning to be just detectable when keying at over about 25 wpm. I'm not good enough on CW to conduct ragchew QSOs at that speed (yet.... working on it) so for me it works, but I'm close to needing zero latency solution now, so I too am looking at getting a local sidetone going driven straight from the keyer. It's not difficult, just not got around to it yet. As with many things in life, simple is often best.

Only thing to watch with local sidetone is of course if you are manually switching (I use footswitch as clicking relays of semi-auto drives me mad) need to allow for the fact that the last character leaves the TX output some milliseconds after the character has finished sounding in the local sidetone! This is combatted (with HL2 anyway) by adjustment of the PTT latency. It works just fine.

Just as an aside, latency is a total PITA in music recording applications also. If you are a musician then there is always much debate with people finding ways to combat latency when adding instruments (particularly via guitar amp simulators) to audio recordings. They nearly always seek recourse to ASIO audio drivers/interfaces that (as far as I understand it) bypass delays in the Windows audio system. Most audio interfaces for instruments (Focusrite Scarlett etc) come with their own ASIO drivers to combat this issue, so we are not alone with this issue!

73

Max

[jdow]

Windows has a new apparently not often used interface that is their answer to ASIO. ASIO is also limited by your sound card or equivalent. They all have a minimum buffer size. For ASIO itself the minimum is 64 samples (at 48ksps). But ASIO4ALL only allows me to take that RealTek on board audio down to about 500 or 600 samples. (I forget the exact number.) At 48 ksps that is about 12.5 ms. Furthermore, the 64 samples, 1.3 ms, still runs afoul of the OS and burps aperiodically as the OS or other tasks do their thing, even though we set the system timing down to 1ms instead of the default two digit timing. The latest OSs make it very awkward to setup a program to run at "realtime" priority class, well above almost anything else. That is the only way we've been able to deliver professional quality low latency audio from a PC. At least this allows a "realtime" priority class "realtime" task priority to work well enough nobody complains when we are running at 64 samples per sample. When the program gets its cue, often by ugly means such as using up a processor with IO polling, it plays "on time" within small single digit ms. If we lower it's priority class to "highest" it can take on quite a bit if variance even with nothing else running. Running at normal priority class is almost comical. The Spiderman car takes its dive with the sound effects at audibly wrong times fairly often, for example. (Reminds me - we have one of those boxes in after it went catatonic from too many sudden Gs and power cycles. The fix should be simple. Getting it done is not. We had some significant hardware changes here and are not fully back on track. It (especially healing) takes more time as you get older, I find.)

{^_^}