Key gets stuck sending CW from keyboard

[Doug Lung]

I like SparkSDR and find it useful for CW using my computer keyboard, which is cleaner and easier to copy than my fist. However, I'm seeing a problem that makes it difficult. Every now and then when I hit a keyboard key my Hermes Lite 2 gets stuck key down - constant carrier. Hitting any other key will complete sending the letter from the stuck key plus the letter from that key. 

For example say I press "D" on the keyboard. The Hermes Lite goes key down (full carrier) until I hit a second letter, say "E".  When I hit"E", the last two dots of the "D" get sent followed by the dot for the letter "E". The problem happens less when I have less of a pause between characters, but that isn't a 100% fix as it can still happen between words. 

I haven't had problems with RF in the shack, but just in case I tried reducing the drive to 10 and the problem still occurred. All this was testing into a dummy load, of course. 

I tried increasing the buffer to 15 ms and the PTT hold to 30 ms but that didn't make any difference. Is there another setting I'm missing? 

Any help is appreciated! 

73, Doug AH6DL

[Doug Lung]

I should have added this happened on SparkSDR 2.0.33 and I upgraded to 2.0.975 but the problem continued. I'm running SparkSDR on Fedora Linux with a hardwired Ethernet connection to the Hermes Lite 2. Other modes work fine. 

[ahop...@googlemail.com]

Hi Doug,

I doubt it is a settings issue, I shall investigate.  How frequently does it happen?

73 Alan M0NNB

[Doug Lung]

I would say every QSO, after a minute or two. It is variable, which I know make it tough to track down. If I keep typing I can sometimes go a minute or so without it hanging but if I pause to think and then start up again it will often stick on the next key press. Not sure but it seems to happen more on characters starting with a dash. Very odd! 

73, Doug AH6DL

[ahop...@googlemail.com]

Hi Doug,

I've managed to partly reproduce this, when it get stuck for me I get the sidetone stuck on but no signal is actually being transmitted. Are you seeing a transmitted signal in the scope/waterfall?  The difference may be caused by me using a simulated radio (a lightning strike destroyed the network link to my shed, should get fixed this weekend).

What wpm are you using? I have also noticed that sometimes typing a single letter does not get sent until you type another, probably connected.

73 Alan 

[Doug Lung]

Hi Alan, 

Traveling on business through next week so no chance to check it, but with the Hermes Lite I'm pretty sure it was transmitting as the PTT was enabled (the PA relay stayed closed) and I don't recall the screen changing back to the receive display. All my testing was at 20 wpm. I hadn't noticed the case of the the letter not being sent until the next key was pressed except when it got stuck. That is, sending a "D" it would stick on the dash and not send the next two dots until I hit the next letter on the keyboard. 

Thanks for your testing on this. If you can get it fixed using SparkSDR with the keyboard to send the CW is a much easier option for me than using a keyer and midi interface, which I haven't gotten around to building yet.

73, Doug

[ahop...@googlemail.com]

Hi Doug,

thanks for that,  just got new network bits so will test on real radio.  There are tricky timing things going on here as spark tries to cope with oddball things like you transmitting wspr whilst in the middle of something else.

73 Alan M0NNB