[time-nuts] Effect of EFC noise on phase noise

Alex Pummer alex at pcscons.com
Tue Aug 2 03:31:41 UTC 2016


Ja Gerhard, bitte schicke mir den LTSpice file,

Danke im Voraus und
73
KJ6UHN
Alex

On 8/1/2016 6:34 PM, Gerhard Hoffmann wrote:
> Am 02.08.2016 um 02:42 schrieb Bruce Griffiths:
>> /"I'm working on a new amplifier based on IF3602 or BF862 FETs that can
>> use 10u foil only."/
>> /
>> /
>> Similar to that published by Groner in Linear Audio?
>> /
>> /
> I know that Groner exists from some web site, but had no personal 
> contact.
> Also I don't read Linear Audio other than 2 articles from Scott Wurcer 
> that I've bought.
> I highly regard Scott, he's the father of the AD797 after all and AD 
> fellow.
> I also had some conversations with him on that.
>
> The preamp will be classical.  Some JFETs in parallel, no source 
> resistors except
> half an Ohm for feedback, more would add to the input noise voltage.
> Cascode with a Zetex bipolar (or whatever they are called now).
> OP37 for loop gain. feedback from OP37 output for 50 or 60 dB gain.
> Post amplifier to 80 db or so.
> Without the cascode, the 1 MHz is not possible. It does not help that
> the feedback limits the voltage excursions on the drain.
>
> I'm not yet sure about the effective input capacitance. I get abt. 1 
> or 1.5 MHz
> bandwidth from a low impedance source. A few nF on the input capacitance
> would be ok, in the end I want it after a ring mixer for phase noise 
> measurements
> but I get unreasonably more in simulation, depending on if I measure 
> it from
> upper frequency corner with a larger input resistor or the resonance 
> frequency
> with an added inductor.
>
> You can get the LTspice file if you like.
>
> regards, Gerhard
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2016.0.7690 / Virus Database: 4627/12724 - Release Date: 
> 08/01/16




More information about the Time-nuts_lists.febo.com mailing list