PSK31

The long awaited experiment was finally conducted and successful results were achieved. So what did we really do? I guess the title would have already explained 50% for what we wanted to achieve. 50% might have been an exaggeration. Ok lets break down the details for our precious PSK31 experiments.

Lets go step by step for all the experiments that were conducted.

First experiment, we procured two personal computers. We later modified the VFO of our earlier version of the receiver the JOTARx. VFO. A XTAL(crystal) was was installed to make it a stabilized Frequency Oscillator. Refer the picture below for a crystal clear understanding.

JOTAVFO modified with a XTAL

Well if your seeing the PCB in a little crazy form please be assured that you are quite sane and that the PCB has been misprinted hence been used in this experiment.

Then we later married this modified FO with a JOTATx. card on our one and once favorite style/trademark Examination board. 

Modified JOTATx.

 As the modified JOTA Tx will be used only for PSK31 experiments we graciously named it as PSK31 Tx.

Now, we connected this PSK31 Tx. to a computer using the computer's sound card, making use of the speaker jack. Why did we use the speaker jack? Good doubt, well we need to transmit only the PSK31 signals. We are not processing any RF signals on the PSK31 Tx. Here are simply just transmitting the PSK31 signal. I guess you will be clear once you read the complete article. Please note that PSK31 is explained completely below, just bare with us till we brag about our experiments.

So, we connected the PSK31 Tx. to the computer.

PSK31 Tx. connected to a Computer

Next, we took a GR-40 Rx. that we built on our Exam board and added a stereo jack so we can connect it to the computer again using the computer's sound card but this time we connect the GR-40 Rx. to the Mic jack as we need the PSK31 signals that are received to be fed to the computer to decode it.

GR-40 Rx. connected to a Computer

Well we sure did take it to the next step, after all we are RnD can't stop at just here. What crazy idea can we think off???

Eureka................Why not try our Famous ISDR to receive PSK31. After all it is a receiver right. We did hook up another computer to our Exam board model of ISDR. I guess by now we have made it clear that we love exam boards...we sure do.

So we went ahead a connected an ISDR to the computer with the same configuration as the GR-40 Rx.

ISDR connected to a Computer

After making all the necessary arrangements and connection, we fired up the PSK31 Tx. and did a little tuning on the ISDR and we were able to successfully receive the PSK31 tones and also the decoded message was quite accurate and clear.

Then we moved on to the GR-40 Rx. and also did a little fine tuning and successfully got the decoded messages. We shall now stop with the bragging and move on to the fine aspects/details of the PSK31 Experiment by looking at the last picture of the total arrangement.

The final arrangement.

The finer details of the experiment:


Note: Please note that all the mentioned software is free to use and open-source. No violations were broken during anytime of the experiment.

Software used for the PSK31 Tx. was a free open-source software called DIGIPAN which is about 700Kb. You can find the following links helpful for you to download, install and also we have provided a link of the user-guide

Digi-Pan Home Page: Click Here
Software Download: Click Here
User Guide: Click Here

The same software was used for the GR-40 Rx. which was an added advantage of having both transmitting and receiving in this software.

As for the ISDR, we alway used ROCKY and we still used ROCKY to push the limits of this free open source software to receive PSK31 Signals. Again couple of links for your help and information.

Rocky Home Page: Click Here

Software Download: Click Here

User Guide for PSK31 in Rocky: Click Here

Here you can see the block diagram for a better understand:

What is PSK31?

"PSK31 or "Phase Shift Keying, 31 Baud" is a digital radio modulation mode, used primarily in the amateur radio field to conduct real-time keyboard-to-keyboard informal text chat between amateur radio operators." : Courtesy of Wikipedia (Click here for link)

"PSK31 is a digital communication mode for amateur radio. It is one of the most common and easy-to-use digital modes as a PSK31 station needs only to consist of an SSB transceiver, an antenna, and a soundcard equipped PC." Courtesy of BPSK31.COM (Click here for link)

"PSK31 is a new digital mode:




designed by Peter G3PLX

that betters SLOWBPSK, an idea and implementation of Pawel SP9VRC

based on the RTTY mode of operation,

useful for live keyboard to keyboard QSO

that works at 31.25 bauds,

that uses varicode caracter coding what gives 50wpm,

easy to use and monitor,

that give very good copy under low Eb/No numbers and is thus suitable for QRP,

that instead of using FSK or on/off keying uses BPSK or QPSK with a Viterbi decoder,

that is available for free for many platforms, including Windows (c) with SoundBlaster type Soundcard,

and uses advanced DSP and narrow band (31 Hz!!) techniques."

Courtesy of  PSK31 OFFICIAL HOMEPAGE (Click here for link)

The links provided have a lot of other information about PSK31 and other related softwares that can be used and utilized. Please do spare a few minutes and have a look at the links. They are very informative and educational too.

We shall now have a look at the whole RnD team having some hands on experience with PSK31.

Stay tuned for more updates and news. Also we really value you most welcomes suggestions, feedback and ideas.

Thank you for your blessings, support and patience for reading our blog.