[hpsdr] caution with cal routine

[Ken N9VV]

There was a famous "overshoot" problem with FLEX gear that was 
documented by Jeff K6JCA:
http://k6jca.blogspot.com/2011/03/tx-overshoot-on-flex-5k.html

I hope that all our OpenHPSDR software takes the overshoot at T/R time 
very seriously. It cost my friend thousands of dollars to purchase new 
power supplies and a new Linear only to find out it was a FLEX problem. 
He blew 5 sets of finals that FLEX replaced. It was a nightmare for him.
He sold his FLEX and bought a Yaesu FT-2000D which he loves. It runs 40W 
in Class-A to his Tokyo-Hy-Power Linear and does a wonderful job.

GL to us all with the new code as it rolls out.
73 de Ken N9VV


On 10/9/2012 4:40 AM, Chris Smith wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Amen to that. I've destroyed a matched pair of MRF454s in my PA using that cal routine.
>
> Chris G4NUX
>
> On 9 Oct 2012, at 07:28, Helmut, DC6NY wrote:
>
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> Hi guys,
>>
>> the new calibration routine in the  PA settings of PowerSDR can fire a lot
>> of trouble in the following PA stages: the automatic loop is starting with
>> the maximum power level and decreasing this level according to the feedback
>> of FWD power. This procedure can damage or destroy following amps due to
>> overload.
>> This cal routine should start with low level of power and increasing up to
>> the target.
>>
>> 73, Helmut, DC6NY
>>
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