PSDR_Si570-LPT
Earlier versions of PSDR had the ability to use the paralell port for control. This may be more reliable than the USB, it will also allow two SDR programs to be run on the same computer. I use SDR-Console or Server with USB control along with PDSR-IQ. Two instances of PSDR may be used with different configuration. There is a warning message when you try, just continue. The Si570 will need a different I2C interface so modification is needed. The I2C lines need to go to PE1NNZ's interface in the Files section of http://groups.yahoo.com/group/softrock40/ Folder Title Si570. Connections vary between PE1NNZ'S version and PSDR-IQ. Information in the software help files.
PSDR-IQ NO fixed frequency TX but the LPT will control the Si570.
Here is the setup. The LPT address needs selecting, the Si570 does not use the AVR so it must be calibrated. This is not too difficult to do by just modifying Xtal Hz. Make sure you keep a note of the default setting, it may make it easier if you lose track!
Below, PDSR v 1.9.0 sr40 shown, different versions will have a few different options.
Frequency.
For a fixed tuned Si570 or crystal the PSDR setup is setup as above. The actual Si570 frequency is entered in the "Center Freq" box.
For WSPR I used Upper Sideband with an "IF" of 10KHz, the centre of the WSPR waterfall will be at 7.0115MHz when PSDR is set to 7.000MHz. Fine tuning I do with the Si570.
These figures are just examples, exact figures will depend on the particular Si570 and soundcard.
Note you may not use fixed frequencies for transmitting with PSDR-IQ. This MUST be controlled by the program.
Note the method of setting frequency in WSPRs "Help" Do not rely on a rig's frequency display, they may well read to one Hertz but may actually be tens of Hertz from the displayed frequency! My method involves a DDS source with a GPS disciplined reference. If I use this to generate a a signal at the WSPR centre frequency it should be exactly at the centre.
A stand-alone LPT Si570 controller here http://groups.yahoo.com/group/softrock40/files/WB8LGA/ DDS.zip You need to be a member.
A possible USB LPT adaptor http://www-user.tu-chemnitz.de/~heha/bastelecke/Rund%20um%20den%20PC/USB2LPT/index.html.en One of these works on my XP setup but I have not tried it for Si570 control yet.
G4ZFQ alan 4 alan @ googlemail . com
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