[hpsdr] Pennywhistle q. about negative feedback

[Chris Smith]

Paul

Please keep me informed of any progress you make on this. I also only need about 5W out from P'whistle to drive a 140W PA from CCI and would rather use f/b than some sort of pad.

Cheers & 73

Chris G4NUX

On 19 Nov 2012, at 07:01, David McQuate wrote:

> ***** High Performance Software Defined Radio Discussion List *****
> 
> Hi Paul,
>  You're the first I've heard of to apply negative feedback.  It sounds like a good idea.  It would be great to have a number of data points that show how IMD performance improves and the corresponding gain & power output.
> 
> On 11/18/2012 2:34 PM, Paul Fletcher wrote:
>> ***** High Performance Software Defined Radio Discussion List *****
>> 
>> Hi all,
>> 
>> I'm playing around with the negative feedback option on Pennywhistle to try and improve the IMD numbers (I only need about 5 watts drive out anyway) and wondered what others have done for the feedback winding on T2? I'm currently using a single turn and R2 / R12 at 10k which gives a noticeable improvement but still develops more power than I need. Any other suggestions on configuration? I'll play around some more but it's always nice to know what everyone else is up to.
>> 
>> 73 Paul
>> M1PAF
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