[hpsdr] caution with cal routine

[Helmut, DC6NY]

Hi Joe,

it seems that using Pennylane in the loop gives much higher ‚loop gain‘  due
to different kind of power control via ALC. If you open the loop, i.e. no
feedback from the coupler on ALEX, Pennylane needs 3 calibration steps to
get full power, while Penelope works more modest and takes 7 steps to reach
full power. Perhaps that's the reason why.

73, Helmut DC6NY

-----Ursprüngliche Nachricht-----
Von: Joe Martin K5SO [mailto:k5so at valornet.com] 
Gesendet: Donnerstag, 11. Oktober 2012 15:58
An: DC6NY Helmut
Cc: HPSDR list
Betreff: Re: [hpsdr] caution with cal routine

Hi Helmut, 

That's interesting.  Thank you for your testing.  I don't have a PennyLane
here to test with so I appreciate the feedback.  Personally, I always elect
to use less than 100% for the Calib Target value when running the automatic
PA Gain Calibration routine.  

RRR, I understand your position.  It is good to always keep in mind that all
of the various HPSDR software/firmware in this project is offered as
"user-be-aware" software/firmware programs.  Of course it is impossible to
write software and firmware that will be optimum for all of the myriad
hardware configurations and external amplifiers that people will have and
will try, but we still try nonetheless. 

Thanks again for the tests.

73,  Joe K5SO

On Oct 11, 2012, at 5:15 AM, Helmut, DC6NY wrote:

> Hi Joe,
> 
> We can watch an improvement, but we could provoke an ‘overshoot’ in the 3.
> calibration step when selecting 100% target. This will happen only with
> Pennylane not with Penelope!
> 
> For my impression the risks of this automatic routine overbalance the
> advantages. Nobody knows what kind of amplifier cascade the guys are using
> and whether the feedback from the coupler is correct.
> 
> Many thanks for your  untiring  activities.
> 
> 73, Helmut, DC6NY
> 
> 


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