Softrock, WSPR, PSDR, and VAC

This page shows how I run a third-party digital mode on a Softrock SDR RX/TX with Power SDR.

This is one way to use WSPR and a Softrock RX/TX, it may help you but there are many variations.

In November 2010 K1JT released a version of WSPR that works directly with SDRs. See the 2.1 supplement. August 2015:- really this is still BETA, IQ is not yet fully integrated. IQ mode is not (yet?) incorporated in the current versions.

PDSR v 1.9.0 sr40 is the version illustrated here. There are many variations of PDSR, some may not have the same options. This version has VOX, others only enable VOX with "Supported Cards" Note this is setup as for a single soundcard with the possible addition of another to be able to hear the received signal.
Some do not recommend VOX but use a Virtual Serial Port. See below.
The Delta 44 is a supported card. I have set it as unsupported as I have three D44s and have had troubles when I have set it as supported. Similarly I have had trouble using ASIO drivers. 

 NOTE:- If you have a Delta 44 use it as a SUPPORTED card! It is unlikely you will have my problems. Setup is automatic, no need for any adjustments. Also if you can use ASIO. It will usually be far better. Is a driver that may be used with cards that do not have ASIO drivers.

Virtual Audio Cable is used to send audio streams between PSDR and WSPR Use v4.09, trouble is reported with the later version.
 NOTE Initially setting the Virtual Cable took several seconds, the screen blanked, I thought there were serious problems! However, no damage was done!
Lots of audio devices! Why WSPR v1.12? Because at the time V2 would not select any of them. Joe has now rectified this. 

PDSR output to Virtual Cable 1 goes to WSPR input. Virtual Cable 2 goes back to PDSR. 
If you want to hear the received audio Audio Repeater that comes with VAC can send it to the on-board sound which has speakers on it's output.
The Delta control panel, driver version This is used with XP. Later versions look different but I presume they have the same setting options.
For maximum power output +4dBu. Input levels set to show antenna noise, at lower HF frequencies Con will probably be correct, for ten metres -10 will be required.
Patchbay/Router H/W 1/2 Out set to Wav Out 1/2. Do NOT use the Monitor Mixer! Setting the output to use this shifts one by 90°, then the 90° of the SDR program's phase difference is added and the two are 180° apart! There will be no TX image rejection! (Maybe just with my particular driver?)



 The large picture below shows settings with an accurately calibrated Si570 controlled by Fred's USB AVR.
Click on the picture to see it all, "Back" returns to this page. Like a normal transceiver PSDR is set to WSPR's dial frequency, the actual signals are 1.4-1.6KHz higher. The thin line on WSPR is my 5.288700MHz DDS marker signal set by GPS. The signal at around 5.2887 on PSDR is actually another transmission from G6WRW. If the PSDR display is set to "Waterfall" it will look like WSPR's display but in real time.
 CFGSR will set the Si570 very accurately if you use the "Callibrate" tab. The basic calibration will not be sufficient. You will have to compare with a known exact standard such as WWV.  I have not carried out this procedure from an on-air source but some form of compensation must be made.
The Si570 divided frequency could be received on an external receiver and CFGSR used to tune to zero beat with WWV, RWM, BPM. Then the Real frequency would be that of the reference station and the Tuned frequency would be that indicated on CFGSR. A second check may be needed.
This program is from  Amateurs, email K5FR for the Windows 7 version. There are several similar free programs available.They enable communication between programs where a COM port is specified. The picture below shows it's Control Panel after I created COM3 and COM4.

This shows WSPR set to COM3, the other end of this "cable" is COM4 which is connected to PDSR setting it to TX mode.

Below shows the other end of the Virtual cable, COM4, attached to the PSDR PTT, setting it to TX when WSPR goes into TX mode.

Below shows PSDR set to key the Softrock on COM1, on my computer this is a real port. Many will use a USB adapter. Adapters with FTDI chips are recommended by many amateurs for reliable operation. Obviously the port numbers will depend on your particular setup.
NOTE All later Softrocks with USB will need this set to "SDR", as lower picture. No COM port is used.

Here are my DSP-Keyer settings, note I found Break In had to be disabled. I presume if I setup the key connections on the LPT it would then work properly and not go into TX.

Accurate calibration helps a lot But you may still need to adjust a few Hz with varying temperature.

If you run XP then PDSR v 1.9.0 sr40 may be the most versatile. It lacks later features but will work well with unsupported soundcards.

PSDR has the capability to control a Si570 by paralell port, LPT. See 
Also here fixed tune Si570, for example with an external controller.

ALL COMPUTERS ARE DIFFERENT! What works on one may not work on another, there are so many things that may conflict or be setup differently. My experiences differ from others, the only way seems to be to try and try until you find out what works for you.

Note much of my use of PDSR has been "try it and see what happens". There is a lot of relevant information on the Flex site and on the sites/Yahoo Groups of the modified versions. It is best you check this rather than just keep settings I have made, that work, but perhaps not properly!

Beta versions of WSPR-IQ are available. These are able to interface directly with Softrocks.  So far no version is fully integrated, if you have mastered the PDSR method I recommend keeping with it until a finished version is released. It could be some time, there have been no new versions since 2010...
All the beta versions need power and some, or all, IQ settings to be made  manually when changing bands. If setup carefully for one band EVERY time the program is used then results are almost as good as PSDR/VAC. 

G4ZFQ alan 4 alan @ googlemail . com
August 2011