[hpsdr] Predistortion and different types of amplifiers?

[Warren C. Pratt]

Hi John,

If you have AutoCalibrate turned on, it will repeatedly recalibrate and 
track the changes.  You can adjust the rate at which the re-calibrations 
occur, per the 'Information' document.

Let us know what you find.  As far as I recall, you are the first to 
gain some experience with an auto-tuner.

73,
Warren  NR0V

On 2/12/2014 4:34 PM, John Marvin wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Warren,
>
> Thanks. Once calibration is complete, how tolerant is the PureSignal 
> adaptation to changes, i.e. if I switch bands, or just move enough in 
> the current band to cause a change in tuner settings, will PureSignal 
> "catch up" to the change as it might need to do with a change in 
> temperature, or would the tuner change be too significant a change for 
> PureSignal to follow?
>
> But you're right, I can probably figure this out from just trying it. 
> My only concern would be PureSignal making things worse due to a 
> possibly more extreme tuner change than I had tested with.
>
> Thanks,
>
> John
>
> On 2/12/2014 5:24 PM, Warren C. Pratt wrote:
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> Hi John,
>>
>> I'd say give it a try and let us know how things go.  My 
>> recommendation would be to let the tuner do its tuning and AFTER THAT 
>> enable AutoCalibrate.  I suspect it will work fine.  You may want to 
>> increase the Amplifier Delay parameter a bit to compensate for the 
>> extra delay through the tuner.  If the tuner begins to tune with 
>> AutoCalibrate ON, you might get some very strange and negative 
>> results because some samples for calibration may be collected at a 
>> different tuner setting than others in the same set.
>>
>> 73,
>> Warren  NR0V
>>
>> On 2/12/2014 2:12 PM, John Marvin wrote:
>>> ***** High Performance Software Defined Radio Discussion List *****
>>>
>>> I noticed that the documentation shows that the rf sampler should be 
>>> connected between the power amp output and the antenna tuner. In my 
>>> case I'd like to try seeing what PureSignal can do with an Elecraft 
>>> KXPA100 amplifier. However, the amp has the antenna tuner built into 
>>> it. What effect will having the antenna tuner in the path have? I 
>>> can easily believe I would need to recalibrate each time the tuner 
>>> changes its settings.
>>>
>>> Thanks,
>>>
>>> John
>>> AC0ZG
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