[amsat-bb] Re: 432 MHz linear amplifier
domenico.i8cvs at tin.it
Sun Oct 12 12:25:22 PDT 2008
----- Original Message -----
From: "Glen Zook" <gzook at yahoo.com>
To: <amsat-bb at amsat.org>
Sent: Sunday, October 12, 2008 5:07 AM
Subject: [amsat-bb] 432 MHz linear amplifier
> At the suggestion of the AMSAT Treasurer I am posting this request to the
> bulletin board:
> What I need the linear amplifier for is a Microwave Modules 432 MHz
> transverter. The 10 watt linear amplifier board is missing and the basic
> exciter only puts out 250 mW. Now I did know the amplifier was missing
> before I traded for the unit so that was not a surprise. The transverter
> works very well but the output power is not sufficient to really do
> anything with and is way too little to drive my 4CX250B amplifier.
> Glen, K9STH
> AMSAT 239 / LM 463
> Website: http://k9sth.com
Hi Glen, K9STH
I am using a transverter Microwave Modules MMT 432/28 S to drive my
4CX250B linear amplifier.
If your original 10 watt linear amplifier board was missed I can send to
you the schematic diagram of it and a picture showing how the components
of it are placed over the PCB.
Into the transverter board you already have a 250 mW driver stage with a
2N6256 or a CTC CD 3649 or a BL524 depending on the year of production.
To duplicate the original power amplifier you need a 2N5944 a 2N5946 and
two pin diodes UM9401 plus a 5 volt regulator.
The rest of the circuit needs only few air trimmer capacitors of 5pF, 10pF
and 27pF .
The above power amplifier do not use a PCB with striplines but only 4 small
silver plated copper wire air wound coils for the inductances so that if you
are able to found the above active devices at a reasonable price you can use
your skill to build the amplifier by yourself.
It is even possible that someone reading on this BB particularly here in EU
hown an old and unused MMT 432/28 S transverter and send to you only the
aluminum box with the 10 watt power amplifier in it.
What say ?...........someone please !
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