[amsat-bb] Re: Preamp protection

i8cvs domenico.i8cvs at tin.it
Fri Sep 15 09:20:33 PDT 2006

----- Original Message -----
From: "Angel Peláez, EA4DUT" <angelkilroy at yahoo.es>
To: <amsat-bb at amsat.org>
Sent: Friday, September 15, 2006 4:10 PM
Subject: [amsat-bb] Preamp protection

> Hi everybody:

> I'm looking for the schematic diagram of a preamp
> protector against TX.
> I know the impressive quarter wave design with square
> brass stock and clamping diodes for 432 EME which
> Domenico, I8CVS, described I don't remember where.

Hi Angel, EA4DUT

Just to remember this is the link


> Rather I'm looking for something much compact as I
> would like to use from VHF to above. I mean one of
> these small boxes (RF diode clippers???) I see
> sometimes on commercial pages which promises withstand
> 25W for a short period I'll appreciate any comment
> about the issue.

I understand but the above filter/protection withstand much
more and tested with 400 watt in to the input less than 80 mW
was measured at the output.

While dimensions are for 70 cm they can be scaled in to any
VHF/UHF/SHF  band adding filtering to protection and it is
very inexpensive and reliable.

> Thanks in advance.

> EA4DUT, Angel
> IN80FF

73" de

i8CVS Domenico

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