apache-labs.com

My only observation about these two items is that the GetPk value changes slightly as Pure Signal goes about the business of correcting non-linearity in the PA of the ANAN (internal coupler being used) or in an external amplifier (external coupler feeding a sample to the bypass port). When transmitting SSB, as you speak the GetPk value will rise and fall apparently in response to the quality of the RF output signal that is produced. I have no idea what that number means or what it does but I assume it's an indication of the Pure Signal algorithm at work.

The bigger mystery to me is the value of the SetPk setting. When I questioned a few ANAN users on the air who were using a mix of Orion II and Orion boards it looks like 0.2899 might be universally applied. However, I'm not sure what SetPk value is used with the Hermes, Hermes 14-bit, and Angelia boards so that might not be correct. In any event, I wonder if anyone can answer these questions:

1. Is this number used across all models of the ANAN radios?

2. If so, why is that number used?

3. What happens if a user increases that number?

4. What happens if a user decreases that number?

5. Is the SetPk number something that could be adjusted by an end user who is having issues with stable correction?

I admit that I experimented with increasing and decreasing the hundredths digit of the default SetPk value by 1 or 2 but could not conclusively see much difference in the behavior of Pure Signal. I didn't "play" further because I really don't know what the SetPk value does and although I like to tinker I don't want to unintentionally invite disaster!

Does anyone on the forum have information about the SetPk setting?

Thanks, Rob W1AEX

Rob,

I read somewhere in a far corner of the Web that you should tailor the SetPk value to closely agree with the GetPk value that appears during PS operation.

So I started playing with my SetPk value by changing it to something between .3400 and .2500 just to see what effect different values had on PS operation. I observed that PS had a difficult (or impossible) time locking into a Correcting condition if I wandered too far either direction from the displayed GetPk value.

So I set my SetPk value to .2916 because that's what's typically displayed in the GetPk field of my particular session. Thetis appears to be very happy with that arrangement. NOTE: your specific value in the Getpk field may differ from mine.

Mark

protocol 1 = 0.4072
protocol 2 = 0.2899

the reset button will always assign one of those two values. If you adjust it, the adjusted value will be used next time. I do need to reset it if protocol is changed in setup (to do).

It is documented on page 106 of the WDSP manual, SetPSHWPeak and GetPSHWPeak.

If you read about GetPSHWPeak in the manual, it will eventually give you a value that should be used for SetPk.

Richie.

Warren - NR0V kindly sent along an explanation for the SetPk and GetPk values that we see in the Pure Signal 2.0 advanced form:

"I happened to see your posting today about GetPk/SetPk. Perhaps I can de-mystify a bit. The SetPk value reflects the gain of the interpolation and decimation filters in the FIRMWARE.
1. The correct value is only a function of the firmware.
2. The correct value does not change from radio to radio.
3. The correct value does not change depending upon the strength of your analog feedback signal.

To my knowledge:
1. For all Protocol_1 releases to date, the correct value is 0.4072.
2. For all Protocol_2 releases to date, the correct value is 0.2899.
3. HermesLite… or other platforms are most likely to be something else, depending upon their firmware.

The GetPk value was originally exposed so I could find out what SetPk was – it was not obvious to the firmware developers. I left it exposed because it helps determine if the firmware is functioning correctly. Slight differences occur between the two numbers due to filter overshoots, etc. Larger differences indicate firmware or other data transport problems.

If you put SetPk only a VERY SMALL amount away from the optimal value, things will probably be OK. If you go farther, you will at times get very unpredictable and bad behavior from PureSignal. If you go farther, PureSignal will cease to work entirely.

The bottom line is that, as the author, I recommend leaving it at the prescribed value for your particular hardware/firmware."