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Re: indoor vs. outdoor downconverter



Hi, Eddie:

I've worked AO-40 with the downconverter directly attached to the dish feed
as well as with a preamp attached to the feed and the downconverter in the
shack (this is how I'm operating now).  First some quick downlink details:
I'm using a G3RUH 60cm spun-aluminum dish with his circularly-polarized
patch feed.  The downconverter I'm using is from Parabolic AB
(www.parabolic.se) and has virtually the same specifications as the UEK-3000
for less than half the cost.  The preamp which is now directly attached to
the patch feed is a DB6NT MKU-232 A2 (with notch filter for 23cm) which is
feeding 22 meters of 9913 coax into the shack where the downconverter is now
located.  With this arrangement, I've worked SSB to apogee and at squints up
to 23 degrees.

While the downconverter has a "crystal oven", like the UEK-3000, there was
some frequency shifting due to ambient temperature differences because the
passive components in the downconverter aren't temperature stabilized like
the LO.  I've talked with others using the UEK-3000 and they've reported the
same experiences.  Moving the downconverter into the shack has eliminated
that for me as the ambient temps vary by no more than 10 degrees.  Also, if
weather claims your preamp, they're much cheaper to replace than a
downconverter!  Another benefit of the "downconverter in the shack" approach
is that the dish can be used, with the preamp, to receive on other portions
of the 13cm band.

Good luck with your ground station.

73 de Rick, KG6IAL

----- Original Message -----
From: "eduardo j valdez" <edvaldez@edsamail.com.ph>
To: <amsat-bb@amsat.org>
Sent: Monday, April 08, 2002 2:51 AM
Subject: [amsat-bb] indoor vs. outdoor downconverter


> Hi,
> i am considering getting a downconverter for ao-40 receive at 2.4ghz with
2 meter IF. UEK brand
>
> the cable run will be 50 feet of 9913 co-axial cable.
>
> antenna would be a ssb electronics dish.
>
> what is the difference of the indoor from the outdoor downconverter from
UEK? will i be able to hear ao-40 with either? rig will be an ft-847.
>
> without regard to the technical aspect, i prefer the indoor type because
it will be protected from the elements.  i shall install it in the
philippines which gets a good amount of sun and heat.
>
> 73,
> Eddie
> DU1EV
> N1WLV
>
> __________________________________
> www.edsamail.com
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