Proposed frequencies for PSK31 QSO

 

The circuit below shows the method I used which isolates the Sound Card Line In and Line Out from the Radio using a couple of Radio Shack transformers, and a 2N2222 transistor to switch the PTT radio line triggered by the RTS line of the computer Com Port. All audio levels are equalized when running either the computer, the SSTV program or PSK31.  To adjust this circuit, tune to a strong carrier and adjust the Rig Volume until the red overload lines disappear. At this point simply tweak RV1 to give the required output power from the transmitter. The author of this page, WM2U, would greatly appreciate any technical updates and or Interface Schematics sent via e-mail. This would ensure the most current information is available to the user, however there is more Radio to Computer interfacing help on the Hook-up page. Try this if you need more information.

To completely isolate the computer from the radio the PTT line schematic shown above should be replaced by the following optically coupled circuit. I have this unit installed and it works great. The Opto Isolator is a 4N29, ECG 3084 or equivalent from Digi-Key, Newark or Radio Shack, part #901-1617. Thanks to Ed Pearson, KF4JU. for the optical circuit.

An e-mail off Ken, W7LAR gives us a great tip by the way. If you want to get the Optoisolator from Radio Shack it will probably not be a store stocked item. You can get it direct mailed to your home by asking the shop clerk to order it for you from their warehouse. It is number 11305190 and costs about $3.00

 

Set sound card sampling rate to 11025Hz This must be at least a 16 bit sound card. No Signal observed? Check your WAVE slider is not zero. Set Rx and Tx frequencies to 1000Hz. NOTE: This value will get you up and running but if you plan on using a filter change it to the center frequency. If using LSB check the "Inverted QPSK" box. Too much noise! Try using a narrow CW filter. Using a Word Processor, write your buffered messages and save them as .txt files, placing em! in a folder called 'buffers' created in the main PSK31 folder. NOTE: This is NOT a form of type ahead buffer. It is simply a method to pre write 'Standard' messages hence saving you keyboarding time. READ THE HELP FILES. Your sound card output must NOT overdrive your Mic Input. Do not overdrive the sound card input from the Radio. Get used to the Waterfall/Phase indicators for tuning. Do not use your Speech Processor. Be patient. This is a new mode. You will not find all the features you are used to yet!

 

These values work but since this is such a new mode things will probably change in the near future. Please e-mail me for any Requests for Change to the Interface or Tips. Your input is crucial to the free dissemination of information. Mark Erbaugh, N8ME runs a great PSK Net on Tuesday nights at 10:00pm EDT on 7.071 MHz. Their a good crew. Come and join us!

To Subscribe to the TARA PSK Reflector: Subscribe at http://groups.yahoo.com/group/070 or send an e-mail to psk-tara-subscribe@egroups.com and put the following in the BODY of the message:      subscribe psk-tara your e-mail address

Wallpaper collector? Hey! check out these new PSK awards offered by the Troy ARA, (TARA). These digital mode awards are part of the All Seasons Contest package and they are very extensive. Check out this site for all the details.  http://www.n2ty.org/seasons/tara_seasons.html

Join in the Signal reporting debate. For PSK there is a lot of talk about the validity of using the standard RST report. One web site that is devoted to this topic is well worth visiting. Goto http://www.psb-info.net/ with an open mind and decide yourself what you think. :)

Pictures over PSK31?  Hey! it's been done! Skip, KH6TY has a web page dedicated to just that. Check out QuikPSK at http://www.qsl.net/kh6ty/psk63/, you'll see :)

One very last word but not by any means the least--- IMD!  It is essential that your signal is clean on the air otherwise you will probably be splattering all over the band. On all the software available you will see a waterfall indicator which shows all the PSK traces available to you to work, however yours is NOT one of them. So how can you see what your signal looks like so you can take corrective action if needed? Well the other station will help you adjust your station until you have a fb trace or would you believe, there are indeed devices available that will allow you to see your own trace. Check out PSK Meter by KF6VSG or IMD Meter by KK7UQ.

I hope the page gives you a taste of the excitement that this new mode is generating. If you need help please feel free to contact me, Ernie, WM2Uand get into the action. See you there, and Enjoy! de Ernie (WM2U)