[hpsdr] PowerSDR Gain settings

[Paul Fletcher]

Hi Chris,

I'm not sure it's that simple. Penny and Pennylane have different output 
stages for a start. I would do this the simple way and begin by taking your 
100W PA out of circuit and measure the output of Pennywhistle, while 
adjusting the gain figures to get 5W out at 100% drive on each band - this 
will give you some idea of a starting point when setting up your 100W PA. 
Also if you are using Penny you want to adjust your input pad for 
Pennywhistle so that Penny is near 500mW for 5W out from Pennywhistle to 
keep the signal as clean as possible (Pennylane shouldn't be affected by 
this as much if at all)

HTH

73 Paul M1PAF

----- Original Message ----- 
From: "Chris Smith" <chris at vspl.co.uk>
To: "HPSDR list" <hpsdr at lists.openhpsdr.org>
Sent: Thursday, September 08, 2011 7:34 PM
Subject: [hpsdr] PowerSDR Gain settings


> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi
>
> Am I right in thinking that the Gain by Band (dB) settings in PA Settings 
> on PowerSDR should reflect the total gain after Penny(lane)?
>
> If I'm interpreting this correctly then assuming a mean gain for 
> Pennywhistle of around 40dB LESS the 6dB pad I have on Pennywhistle's 
> input PLUS the 14dB mean gain of my PA the TOTAL gain = 40 - 6 + 14 = 
> 48dB.
>
> Should I set the Default gain to 48 or all band gains to 48 before doing a 
> Calibrate with a Cal. Target of 100(W?)? What is the Advanced Calibration 
> Routine?
>
> I'm asking because I think I've destroyed the pair of MRF454s in my PA by 
> over driving them. :-(  I believe I should have had a 12dB pad on the 
> input of Pennywhistle to limit the input to my PA to 5W.
>
> 73
>
> Chris G4NUX
> _______________________________________________
> HPSDR Discussion List
> To post msg: hpsdr at openhpsdr.org
> Subscription help: 
> http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
> HPSDR web page: http://openhpsdr.org
> Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/
> 


 1315515504.0