[hpsdr] caution with cal routine

[Joe Martin K5SO]

Hi Helmut, 

RRR, perhaps.  I have a Hermes, which uses the same Tx drive scheme as PennyLane, so I should be able to test things here for both Penelope & PennyLane operation.  

I'll examine the situation some more.  Thanks.

73,  Joe K5SO

On Oct 11, 2012, at 10:09 AM, Helmut, DC6NY wrote:

> 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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