[eagle] Re: PAVE PAWS EMI
ku4os at cfl.rr.com
Mon Sep 3 16:42:49 PDT 2007
This reminds me of a briefing we got at work from a UHF receiver vendor
regarding their receiver's susceptibility to radar. In it they demonstrated
how a strong enough RF pulse would actually cause a bias shift on the first
stage resulting in a 'blanking effect' until the RF induced voltage decayed
off. Perhaps we're seeing something similar here?
On Monday 03 September 2007 14:32:05 Juan Rivera wrote:
> The noise blanker is off and when you think about it, it doesn't matter
> anyway since I'm pulling the 10.7 MHz 3rd IF out of the TS-2000. The noise
> blanker is implemented in DSP farther downstream. I'm not sure what is
> causing that. I'll have to scratch my head some more...
> -----Original Message-----
> From: Dave hartzell [mailto:hartzell at gmail.com]
> Sent: Monday, September 03, 2007 10:58 AM
> To: Robert McGwier
> Cc: juan-rivera at sbcglobal.net; David Smith; Dave Black (Work); Dave Black
> (Home); eagle at amsat.org; Samsonoff at Mac. Com; Juan.Rivera (Work)
> Subject: Re: [eagle] Re: PAVE PAWS EMI
> Attached is a Matlab plot of Juan's SDR-IQ PAVE PAWS capture...
> In the plot, you can really see the noise-blanker suppression after
> each spike...
> On 9/3/07, Robert McGwier <rwmcgwier at gmail.com> wrote:
> > Juan Rivera wrote:
> > > Hi Dave,
> > >
> > > I noticed that too. I killed the AGC but didn't think of the noise
> > > I'll take a look and try again if it was on. Right now I can't
> > > with the CAN-Do module or I would switch to the 70 cm prototype
> > > receiver
> > > repeat the test.
> > >
> > > Juan
> > Yes, please. I have some interesting noise blanker stuff I want to work
> > on to eliminate PAVE PAWS pulses on board the SDX transponder. This is
> > the PERFECT set of signal collection (SDR-IQ of IF) for doing that work.
> > Thank you very much once again Juan for your extremely valuable
> > contributions and your unbridled enthusiasm. It is very welcome indeed.
> > Bob
> > --
> > AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL,
> > TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair
> > "If you're going to be crazy, you have to get paid for it or
> > else you're going to be locked up." Hunter S. Thompson
> Via the Eagle mailing list courtesy of AMSAT-NA
> Eagle at amsat.org
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