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Re: RE: 2m to 10m to 70cm converters



Robert,
Let us assume that you use two audio tones 900 and 1900 HZ fed into a 14 MHz
transceiver with the resulting output being 14.000900 and 14. 001900 times
31 = 434.0279 and 434.0589, with the difference between the two tones of 31
KHz.
A varactor diode is also non linear, requiring some power through it when no
audio is present.
 All SSB signals must be mixed up or down not multiplied. Also mixes on the
high side, if the IF is less than the mix results in the opposite sideboard.
Art, KC6UQH

----- Original Message -----
From: "Robert Bruninga" <bruninga@usna.edu>
To: <amsat-bb@amsat.org>; <pe1rah@yahoo.com>
Sent: Sunday, June 05, 2005 9:24 AM
Subject: RE: RE: [amsat-bb] 2m to 10m to 70cm converters


> >>> William Leijenaar <pe1rah@yahoo.com>
> >The biggest problem is only to get from
> >HF on 70cm uplink.  These upconverters from
> >28MHz to 435MHz are very rare and...expensive.
>
> But they dont have to be I dont think.  Remember
> the old high-level varactor diodes.  Just one
> active part.  Hit it with plenty of power at 14
> MHz SSB and plenty of power at 449 MHz
> carrier from two rigs and then filter the resulting
> RF mess to only pass 435 MHz and you should
> be able to get a few watts there.
>
> In fact, I thought these days if you cant find the
> old high-power varactor diodes, that  you can
> simply parallel say about 36 1N4148's to handle
> the power and do the same thing.
>
> This depends heavily on people building the
> good filters on the output to keep all
> spurrs down.  But it should work.  This high-level
> mixer doesnt even need a power supply.
> It is totally passive.
>
> I'd love to have time to experiment with this,
> but alas, no time...
>
> de Wb4APR, Bob
> ----
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