[Premium-Rx] :-VLF PRESELECTOR

[Peter Rovardi]

Hi Nigel,
I thought it seemed a little too simple to be true but thought, as you do, it might just be worth a try.

And yes,100uV of DC to HF would at least, I suppose, make a great Noise Generator for a  S9+ signal level!!!.

Any advice on a good circuit for a very sharp VLF Preselector anybody?

Regards

Peter   G4HSB.
  ----- Original Message ----- 
  From: GandalfG8 at aol.com 
  To: premium-rx at ml.skirrow.org 
  Sent: Wednesday, November 22, 2006 8:38 PM
  Subject: Re: [Premium-Rx] *** SPAM *** Re: Wellbrook excellence !


  In a message dated 22/11/2006 20:10:41 GMT Standard Time, peter at rovardi.wanadoo.co.uk writes:
    .(Currently playing with a Krohn -Hite Variable Dual Filter  LP 
    /HP.150Hz - 1.5MHz . Model 3200R )
  -----------------------------------------------------------------

  Hi Peter

  I'm also a Wellbrook enthusiast, although have only used the smaller loops so far, but would suggest some caution when it comes to the Krohn-Hite filters.

  I first came across these a few years ago and thought they were worth a try at LF but forgot that what passes for "low" noise in a reasonably high level audio filter might not be quite the same at low level RF.

  My practical results were not encouraging and, as I understand it, the spec allows up to 100uV of internally generated noise which is quite a lot to push into a receiver.

  regards

  Nigel
  GM8PZR




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