开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育
  1. QRPLabs
  2. Topics

No Sound Card digital modes

 

Suppose that WSJT-X could be modified to side-step the whole 'translate the desired rf frequency to an audio tone, send the tone out on an audio cable to the radio, where the tone is mixed in on the baseband carrier, after which the carrier and all the intermodulation artifacts are filtered out', and simply send the required rf frequency (the baseband plus tone) to the radio.? The QDX could side-step the sound card and generate the appropriate rf frequency directly (rather than detecting the appropriate frequency by means of the sound card, and then generating the frequency directly).
 

开云体育

Yep, that would certainly make sense, and has been mentioned before. However, it would require a fairly major revision to wsjtx, and since it works as is (even if it’s not technically the most efficient), they are unlikely to put in the work to “fix“ the problem.

73, Willie N1JBJ

On Aug 25, 2023, at 10:38 AM, KI7MWA via groups.io <entilleser@...> wrote:

?Suppose that WSJT-X could be modified to side-step the whole 'translate the desired rf frequency to an audio tone, send the tone out on an audio cable to the radio, where the tone is mixed in on the baseband carrier, after which the carrier and all the intermodulation artifacts are filtered out', and simply send the required rf frequency (the baseband plus tone) to the radio.? The QDX could side-step the sound card and generate the appropriate rf frequency directly (rather than detecting the appropriate frequency by means of the sound card, and then generating the frequency directly).

 

Wsjtx does however at least show what is being sent and received in two places other than the screen. In the UDP data stream, and logged in the all.txt file.
What I managed to do for my experiment is to track the all.txt file with a small node.js app, encode that message to ft8 frequency offsets and send that number via serial port to the Arduino that controls the si5351.
It is clumsy but it kinda works. And no visible latency either.?

While this is far from finished and useful, it is an idea how annoying "audio coupling" between wsjtx and a transceiver that does direct signal generation can be done with a small software shim.

In theory, it wouldn't be too hard to add optional "current message output" to existing wsjtx cat serial data, but haven't explored that yet.?
 

Hi All

The use of audio as the universal way of transferring digital Signal modes between a PC and a radio transceiver makes lots of sense in many ways. Every radio transceiver for more than a century has an audio output and if it's a phone transceiver, an audio input. So the digimodes software writer knows that his software will be automatically compatible with every radio in excistence.?

The moment a Digi mode software starts producing custom ways of sending out digital symbol information, it's no longer compatible with anything. And every radio model then has to update it's capability (if it even is possible) to handle these messages.?

So it's not really a logical direction.?

The way QDX and QMX are designed with the built in USB sound card emulation, the transfer of audio between PC and transceiver is lossless, distortion free, hum free, etc. It's quite straightforward and fast, and incredibly accurate, measuring the audio frequency and applying it at RF. So the system as it stands, doesn't cause any problems and wouldn't be improved by any other method.

73 Hans G0UPL


On Sat, Aug 26, 2023, 1:24 PM Vojislav [YU4HAK] <batica@...> wrote:
Wsjtx does however at least show what is being sent and received in two places other than the screen. In the UDP data stream, and logged in the all.txt file.
What I managed to do for my experiment is to track the all.txt file with a small node.js app, encode that message to ft8 frequency offsets and send that number via serial port to the Arduino that controls the si5351.
It is clumsy but it kinda works. And no visible latency either.?

While this is far from finished and useful, it is an idea how annoying "audio coupling" between wsjtx and a transceiver that does direct signal generation can be done with a small software shim.

In theory, it wouldn't be too hard to add optional "current message output" to existing wsjtx cat serial data, but haven't explored that yet.?

1 - 4 of 4