[amsat-bb] Re: New Preamp

i8cvs domenico.i8cvs at tin.it
Tue Sep 18 09:17:26 PDT 2007


----- Original Message -----
From: "Gary Memory" <gmemory at tks-net.com>
To: "'Jim Jerzycke'" <kq6ea at pacbell.net>; "'Bob Stewart'" <bob at evoria.net>;
"'Amsat-BB'" <amsat-bb at amsat.org>
Sent: Tuesday, September 18, 2007 8:22 AM
Subject: [amsat-bb] Re: New Preamp
>
> I have a WACCOM cavity filter for both VHF and UHF that I'd like to use at
> the mast head, but they are too big to get up there (and they are not
> weather proof).  Oh, and they are only a couple dozen KHz wide, which
makes
> tuning to a different frequency a bummer.
>
>
> Gary, N7BRJ/DA1BRJ

Hi Gary, N7BRJ/DA1BRJ

For my similar situation in the bay of Naples wich is full of RF pollution
I use the following K3PGP home brewed filter at the mast head in front to
the low noise 70 cm preamplifier and a 70 cm cavity filter in the shack in
front of my 70 cm downconverter or 70 cm receiver.

Please read the article.

http://www.k3pgp.org/432filter.htm

Similarly for 2 meters I have scaled the dimentions of the above filter wich
is antenna mounted in front of the 2 meters preamplifier and a 2 meters
cavity filter of the type used for the FM repeaters is in the shack in front
of my 2 meters downconverter or receiver.

I remember receiving OSCAR-13 on 145.950 MHz I was able to locally
translate the satellite at 145.250 MHz FM transmitting with 2.5 watt using
another antenna to show locally the satellite performance without desensing
the bird.

This setup is obviously permanently tuned and devoted for receiving the
70 cm and 2 meters satellite bands and it works.

73" de

i8CVS Domenico





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