[hpsdr] Front End protection

[Giancarlo Moda]

Hi Henry,

I believe that front end protector "Cyberus" has a
nice name and certainly it may protect the HPSDR front
end and others too... from anything will try to get
"converted" to 0s and 1s...

73

Gian
I7SWX

--- Henry Vredegoor <henry.vredegoor at gmail.com> wrote:

> Hi all,
> 
> Shouldn't we call it Cyberus?? .......    
> 
> Defender of the gate that leads from RF-space to
> Cyberspace.........
> 
> ;-)
> 
> Henry.
> 
> 
> 
> > -----Original Message-----
> > From: hpsdr-bounces at hpsdr.org 
> > [mailto:hpsdr-bounces at hpsdr.org] On Behalf Of
> Giancarlo Moda
> > Sent: donderdag 22 februari 2007 16:25
> > To: hpsdr at hpsdr.org
> > Subject: Re: [hpsdr] Front End protection
> > 
> > 
> > ***** High Performance Software Defined Radio
> Discussion List *****
> > 
> > Hi  all,
> > 
> > Cerberus or Kerberos (Greek ÊÝñâåñïò, Kerberos,
> "demon
> > of the pit") was the hound of Hades, a monstrous
> > three-headed dog with a snake for a tail and
> > serpentine mane.
> > 
> > Our ADC may need something better than Cerberus as
> he
> > was overcome several times:
> > 
> > • Hercules' final labour was to capture Cerberus,
> > which he did by wrestling it into submission.
> > Fightings between old mixers, qsd and adc could
> give
> > highly distorted and spured signals.
> > 
> > • Orpheus used his musical skills to lull Cerberus
> to
> > sleep.
> > This could be a danger coming on 40m from
> Broadcasters
> > splatters and signals 
 and IMD !!!
> > 
> > • Hermes put him to sleep with water from the
> river
> > Lethe.
> > Water should not be a problem.
> > 
> > • In Roman mythology, The Sybil of Cumae lulled
> > Cerberus to sleep with drugged honeycakes in order
> to
> > permit Aeneas fuller entry to the underworld.
> > Maybe today we could use some good original
> italian
> > spaghetti  and good wines 
 still through
> > advertisements on broadcast  transmissions ... lot
> of
> > IMD !!!.
> > 
> > • In a Greek tale, Psyche also lulled Cerberus to
> > sleep with drugged honeycakes.
> > Maybe we will have to watch some of those sweety, 
> > flashy and porno electrons flying in the air...
> > 
> > Any addition to the front end wiull bring possible
> > noise figure increase, attenuation, distortion..
> ??
> > Maybe we could use a couple of LEDs like the old
> NE-2
> > gas lamp used with valve/tube RXs (my homebrew RX
> 17
> > valves plus a nuvistor had an NE-2 ...not only
> Drake
> > .. hi). Two leds in parallel but opposite
> > pinsconnection could work ... flashing and or
> > blowing.... these are only two heads of our
> electronic
> > cerberus .... people that can afford it could test
> > them in such an application.
> > 
> > 73
> > 
> > Gian
> > I7SWX
> >   
> > 
> > Message: 12
> > Date: Thu, 22 Feb 2007 12:14:02 +0100
> > From: Jeroen Bastemeijer
> <J.Bastemeijer at TUDelft.nl>
> > Subject: Re: [hpsdr] Front End protection
> > To: FRANCIS CARCIA <carcia at sbcglobal.net>
> > Cc: hpsdr at hpsdr.org
> > Message-ID: <45DD7AFA.40408 at TUDelft.nl>
> > Content-Type: text/plain; charset="us-ascii"
> > 
> > Hi Francis,
> > 
> > It wasn't a god, but a dog-like creature called
> > Ceberus (if my memory 
> > serves me well).
> > 
> > In my opninion a combination of resistors and
> diodes
> > (to the power 
> > suply 
> > lines) is the best solution. The resistors will
> limit
> > the current and 
> > provide some "soft clipping". By soft-clipping all
> > sorts of distortion 
> > generated by the receiver are avoided.
> > 
> > Regards, Jeroen PE1RGE
> > 
> > FRANCIS CARCIA wrote:
> > 
> > >***** High Performance Software Defined Radio
> > Discussion List *****
> > >
> > >  
> > >
> > >
> > > 
> >
>
--------------------------------------------------------------
> > ----------
> > >
> > > I don't know which Greek God guarded the gate
> but
> > how are we going to 
> > > protect this fast A/D from static and lightning
> > transients? Racal 
> > used 
> > > an interesting active limiter ahead of the
> RA6830
> > because the older 
> > > RA6790 had real bad burnout problems with the
> FETs
> > in the first 
> > mixer. 
> > > I would think we need more than a NE2 across the
> > input.  Frank WA1GFZ
> > >
> >
>
>-------------------------------------------------------------
> > -----------
> > >
> > >_______________________________________________
> > >HPSDR Discussion List
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> >
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> > http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/
> > >
> > 
> > -- 
> > Ing. Jeroen Bastemeijer
> > 
> > Delft University of Technology
> > Department of Electrical Engineering
> > Electronic Instrumentation Laboratory
> > Mekelweg 4, Room 13.090
> > 2628 CD Delft
> > The Netherlands
> > 
> > Phone: +31.15.27.86542
> > Fax: +31.15.27.85755
> > E-mail: J.Bastemeijer at TUDelft.nl
> > 
> > 
> > 
> > 
> >  
> >
>
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> 
> 
=== message truncated ===



 
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