FLDIGI problems with Serial PTT
I am running FLDIGI in Linux UBUNTU 11.04 everything works great except the ptt. I am having problems with selecting the correct device to key the PTT. I am using a USB to serial adapter to a homebrewed interface that works fine, even worked before on UBUNTU, but changed HDD's and reinstalled, now not so lucky.
Any help would be appreciated. It gives me a choice of 20 different devices. I get/dev/ttyXX XX= 50-30
I started going through the list but quickly lost my desire to chase down the device this way, and am hoping for a better solution, otherwise I will have no choice but to do the daunting task.
No good deed goes unpunished.
A USB adapter will likely be found as /dev/ttyUSB0 and upwards. If you have two or more, they can be assigned in any order. Solving that requires some udev magic and I'm not a udev guru.
Are you using rig control? If so, your radio may be able to key and unkey the PTT via a rig control command. I find that it works well and eliminates the need for an additional serial dongle.
You do NOT need a PTT line to operate most digital modes!!!
99% of the schematics you see on the Internet tell us that we need to control the PTT line to put our transceiver into transmit mode, but that is NOT the case. VOX works just fine to key the rig. I operate PSK31 using Fldigi, and I don't have a thing connected to my PTT line.
The audio from your computer's sound card going into your microphone input is ALL you need to key the rig. Turn on your radio's VOX feature, and play with the VOX GAIN and VOX DELAY controls. Magic, isn't it? :-)
Of course, you're right, but it is helpful, when using this method, to disconnect one's microphone.
Member: Backyard Engineering Group
I think you missed the part that I am going through the DATA port, NOT the MIC, been there done that, works great so long as you don't wish to use voice at same time, cause you have to swap all the time.
Originally Posted by W0BTU
Your right you don't need the PTT, but that wasn't the question or point of my question, it is already existing, and works just fine, so I will NOT be modifying, my home-brewed interface.
I have used acoustic and VOX before, but it is no longer acceptable at this station, as we have changed a few things here. we have several machines and radios, but none with rig control, these rigs predate dinosaurs!
meant to comment on this in other post, oh well stuff happens!
Originally Posted by N0NB
I have been through all this in the setup, and even with "dmesg", or "lsusb" renders no results, in fact not seeing the device at all on the machine. I know it works as it worked once before on UBUNTU, but I screwed the system recently, and had to dump and start all fresh again. In the settings, I see a list from ttyS0 - ttyS31, but none of them will activate. I have even gone as far as gtkterm, and still no results. I am pretty sure it is opperator error, just which error is the question!
If you open a terminal session and issue the command:
does anything show up?
Originally Posted by K7JBQ
Yes, you are right. :-)
I guess I'm just sick and tired of seeing the "you absolutely MUST use the PTT line for PSK31!" mantra echoed almost everywhere (in both text and schematics). That is so misleading, and does a disservice to many people who want to try out the HF digital modes.
It only takes me a second to unplug my 8-pin mic connector and plug in my 8-pin sound card connector if I want to switch to PSK31.
I have the same problem with the same setup, Ubuntu Linux and FLDIGI. The rig I have does not have a VOX so I needed a way to hard key the PTT line. The March 2011 QST had an article describing a circuit that used the audio to drive a transistor which pulled down the transceiver line. The main drawback being intermittent modes (Hell scriber) won't hold the transistor on. My fix is to use the 1Khz VOX option in FLDIGI. Go to configure, rig control, Hardware PTT tab. On top is right channel PTT tone check box. This will place a constant 1000 Hz. tone on the right channel when transmitting. The left channel drives the SSB audio, while the right channel is rectified filtered and used to driving the keying circuit. Using the balance control, level setting is easy.