Re: [amsat-bb] Re: Drake 2880 power

["Frederick M. Spinner" <fspinner@xxxxxxxxxxx>]

I'd recommend a good stable low-noise amp, like a MAR-6 for that 
application.  About $2.00 last time I've checked.  My only concern is about 
the comments on the mod pages about excessive gain out of the Drake.  So 
maybe a 20 db pad (just resistors-- nothing fancy) and a MAR-6 is more 
appropriate of a solution.

MMIC circuits typically consist of two coupling caps, a bias resistor, and a 
RFC to supply power to the MMIC.  So in parts, with an "injector" you're 
looking at about $10-$15 plus the box to put it in.

Now I'm still thinking an un-recrystaled Drake at 120 MHz mixed with
a 70MHZ computer clock osc = a 50 MHz IF is a good idea, particularly for 
those of us with FT-847s..  The mixer circuit could have a MMIC after the 
mixer for similiar TX protection.

Fred W0FMS


>From: Doug Faunt N6TQS +1-510-655-8604 <faunt@panix.com>
>To: cbuttsch@slonet.org
>CC: amsat-bb@AMSAT.Org
>Subject: Re: [amsat-bb] Re: Drake 2880 power
>Date: Wed, 31 Jan 2001 00:16:05 -0500 (EST)
>
>Can we have more details, like which MiniCircuits parts are
>appropriate, and what to watch out for when putting this together?
>73, doug
>
>
>    Date: Tue, 30 Jan 2001 11:20:35 -0800 (PST)
>    From: Clifford Buttschardt <cbuttsch@slonet.org>
>    Cc: amsat-bb@AMSAT.Org
>
>    On Tue, 30 Jan 2001, Doug Faunt N6TQS +1-510-655-8604 wrote:
>
>    > As long as people are thinking about the bias Tee for power, perhaps
>    > something could be added to that to provide protection from
>    > transmitting into the converter: perhaps a sacraficial(sp?) cheap
>    > unity gain, low-enough noise, amp?
>    >
>    > 73, doug
>    >
>
>
>    This is a very good idea!  I use a small Minicircuits block amplifier 
>with
>    fifty ohm in and out impedance just to accomplish this.  Cliff K7RR
>
>
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