[hpsdr] PowerSDR Gain settings

[george byrkit]

Chris,
It's 'feeds back' as in 'provides to', not 'feedback in a closed loop
response system', of course.

You may be right about the 'calibrate' function in PowerSDR (I'll let Bill
KD5TFD or others who maintain that speak to that), but of course it's not
used while running to do anything like ALC.

It is regrettable about the toasting of some fine MRF454s.  A number of
those Motorola beasts are no longer available, such as the ones used in
Hercules, resulting in its demise.

73,
George K9TRV 

-----Original Message-----
From: Chris Smith [mailto:chris at vspl.co.uk] 
Sent: Friday, September 09, 2011 3:29 AM
To: george byrkit
Cc: HPSDR list
Subject: Re: [hpsdr] PowerSDR Gain settings

Hi George

Thank you for your response.

I was very lax in my use of English. I didn't mean to imply that Alex
performed the ALC function but that this function probably existed in the
s/w or FPGA of Penny(lane) as a result of the information provided by Alex.

Actually I don't think my assumption was too far off target. The Calibrate
(to a target) function in PA Settings of PowerSDR must use the fwd power
level fed back by Alex to monitor the final o/p. How else would the s/w know
what the overall gain of the PA was?

I have to admit that I'm VERY annoyed with myself for destroying a perfectly
good matched pair of MRF454s because of my own stupidity.

I was aware that the only ALC function that I've seen mentioned in the
documentation is that performed by Penny(lane) to limit the o/p to 0.5W.
Thanks to Dan Mitchell, W0IQ, for refreshing my memory yesterday.

73

Chris G4NUX

On 9 Sep 2011, at 07:12, Chris Smith wrote:

> ***** High Performance Software Defined Radio Discussion List *****
> 
> Hi George
> 
> I was assuming, as Alex feeds back the fwd & rev power to Mercury and
thence to Penny(lane), that this would/could be used as ALC by PowerSDR. I
was obviously mistaken in my assumption.
> 
> 73
> 
> Chris G4NUX
> 
> On 8 Sep 2011, at 23:14, george byrkit wrote:
> 
>> ***** High Performance Software Defined Radio Discussion List *****
>> 
>> Dear Chris,
>> Alex of course has no ALC.  It's not at all shown as having that in the
>> schematics, nor is it described as having that feature (ALC) in its
manual.
>> Why would you think that it had such a feature?
>> 
>> That said, ALEX power levels are for reporting 0-about 110W.  Penny power
>> level reporting is appropriate for Penny only (0 to .5w).  It would be
hard
>> for either to be otherwise.
>> 
>> 73,
>> George K9TRV
>> 
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