WSPR 2.1 for I/Q SDRs

Hi all,

The 3 dB deficiency in signal-to-noise of WSPR 2.10 has been traced and corrected. It was an image-rejection problem: not the image about the SDR's LO frequency, but rather the image about the "digital BFO" converting WSPR signals to audio around 1500 Hz. An easy fix, once I understood what I had done wrong.

If you want to use WSPR 2.1 with 3 dB better Rx sensitivity, you can download it from:

http://www.physics.princeton.edu/pulsar/K1JT/WSPR2.10_r2179.EXE

Other changes in r2179, relative to r2165:

1. As many users discovered, the "0 dB" level had been set much too high. It has been re-defined at an appropriate level.

2. I/Q mode setup parameters have been moved from menu item "Setup -> Advanced" to "Setup -> IQ Mode". The checkboxes for "Enable I/Q mode", "Reverse Rx I,Q" and "Reverse Tx I,Q" behave as in previous versions.

3. New controls have been added for "Tx dB", "Tx I/Q Balance", and "Tx Phase". You can use "Tx dB" to reduce the amplitude of Tx audio tones (and thus your Tx output power, assuming a linear transmitter) by a specified number of dB. The Balance and Phase controls are not yet functional, see below.

Still to Come
-------------------
In coming days, time permitting, I hope to implement the following:

1. Full implementation of controls for Tx image rejection.
2. Automatic image rejection for Rx.
3. Control of Si570 and SoftRock T/R switching via the hamlib "rigctl" program, as for other CAT-controlled radios. (This will enable program control of SoftRock from Linux, as well as Windows.)
4. Some general code cleanup.

... and possibly ...

5. Real-time waterfall display of the full 48 kHz passband, or selected subsets thereof.

As always, please continue to send reports/suggestions when you have something to contribute!

-- 73, Joe, K1JT