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Re: 1.2ghz options



I did something similar a few years ago. The DEMI weak signal source can be
used to generate the LO. It has lower spurs if you multiply crystal
frequency by an odd number and use back to back PIN diodes for the
multiplier. RF Parts and Surplus Sales of Nebraska have MiniCircuits mixers
available cheaply and the ARRL Microwave Handbook has design information for
interdigital filters that can be built from brass tubing and sheets from the
hobby store.

73,

John
KD6OZH

----- Original Message -----
From: "Mike Kana" <cosmo224@execpc.com>
To: <amsat-bb@AMSAT.Org>
Sent: Friday, 02 February 2001 02:49 UTC
Subject: [amsat-bb] 1.2ghz options


> Howdy all
>
> Ok, here are some random musings to get on 1269MHz.  A homebrew route
> would be build up a transverter from surplus.  A good source (pun
> intended...)
> for an LO would be to take a California Microwave or Frequency West
> brick
> oscillator who's pre-srd frequency would tune in the range of 1269 -/+
> the IF.
> (Remember that high side injection flips the tuning and sidebands).  The
> mixer,
> and first gain stages could be realized by using a Minicircuits mixer
> and surplus
> 1 to 1.5 Ghz gain stages.  The filters could be interdigital types using
> plans from
> the RSGB microwave manual or hair pin filters.  Curious what type of
> pipe cap
> would be needed to build a simple single stage filter?
>
> The 'high power' stage would be a DEMI kit to get to the 3 watt range.
> This
> could drive another gain block then feed a 2C39 cavity amp (designs from
> the
> Handbook)
>
> Another thought would be to use a DEMI 1296 weak signal source
> recrystaled
> to tune to 1269 for a CW only rig driving one of the 'pod' amps?  (Has
> anyone
> successfuly got one of those running?)
>
> Finally, here is the long way to get there.  Use a HF rig running 21.15
> MHz driving
> multipliers (varactor or otherwise....) to generate the 1269 signal
> (1269/60 = 21.15).
>
> Ok, there are some quick and dirty ways to get a mode L signal.  Any
> other thoughts?
>
> 73 de AA9IL
> Mike Kana
>
>
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