Transceiver wg. M0NKA

[SP6LTP]

Pojawiła się nowa wersja softu 0.0.183 od KA7OEI :


- The AGC has been improved even more. There is not (yet) an interface with the UI so it is still "fixed" at a medium-slow rate, but the "pumping" or "clicking" has been reduced.

- The RX line output is now fixed (by the AGC) at 0.5 volts RMS, fixing a bug in which it would change (somewhat) with the volume control.

- A few minor things that I have forgotten...

* * *

The major change, however, is the complete revision of the filters - NONE of them are the same as before.

- 300 Hz CW filter - centered at 750 Hz, -6dB @ 605, 896 Hz, -20dB @ 542, 941 Hz, -40dB @ 378, 1034 Hz, -60dB @ 118, 1300 Hz

- 500 Hz CW filter - centered at 750 Hz, -6dB @ 480, 1034 Hz, -20dB @ 410, 1084 Hz, -40dB @ 304, 1184 Hz, -60dB >1283 Hz

- 1.8 kHz Narrow SSB: -6dB @ 539, 2347 Hz, -20dB @ 500, 2519 Hz, -40dB @ 437, 2886 Hz, -60dB @ 393, 3188 Hz

- 2.6 kHz SSB: -6dB @ 291, 2590 Hz, -20dB @ 266, 2838 Hz, -40dB @ 225, 3330 Hz, -60dB @ 200, 3730 Hz

- 3.6 kHz Wide SSB (lowpass): -6dB >3600 Hz, -20dB >3765 Hz, -40dB > 4028 Hz, -60dB > 5000 Hz

- 10 kHz Wide (lowpass): -6dB > 10.0 kHz, -20dB > 10.18 kHz, -40dB > 10.46 kHz, -60dB > 10.88 kHz

All of these new filters are IIR-based, which for limited CPU capacity, can provide more "bang for the buck" in many cases. These are very much sharper than the original filters, as well.

Note that you can change to any filter in any mode. Once the EEPROM save is working, it will "remember" which filter was selected on which mode - and it may limit the selection of the filters somewhat, say, to only 300, 500, 1.8k and 2.3k in CW mode and prevent the CW filters from being selected in the SSB mode.

It should also be possible to provide a degree of Passband tuning (e.g. IF Shift) - but this would, of course, would require a user-interface rework - and a fair amount of work. This wouldn't be a "true" IF shift, but actually a number (say, half-dozen or a dozen) separate filters that are selected as one "tunes" the offset - but THAT is a project for another day, a ways down the road!