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Re: Drake on 122 Mhz



Hi Kent, I'm also using a Drake still on 122MHz output. I incorporated the
early
modifications to increase the IF gain and to reduce the front-end noise
figure. This
was used with a simple 14 turn Helix to listen to and decode the AO-40
beacon.

Now I operate it with a DEM 13ULNA preamplifier which has ample gain and a
measured input noise figure of 4.7dB. (System noise figure 0.6dB using an
ICOM
PCR-1000.) Main thing is to keep lead lengths to the absolute minimum
between
the antenna & the pre-amp, and the preamp & the Drake. Like most folk, I've
got
the DEM mounted at the atenna feed point so there is no coax, only the
connectors.
I'm using about 3 feet of RG-8 between the DEM and the Drake, this has
hardly
any effect on the overall performance. (I'll send you a picture by direct
email.)

Circular polarisation is a must, perhaps you are using an unmodified BBQ
dish and
need to cover the reflector with some mesh and use a circular polarised
feed, either
a short (4.25T) helix or a Patch. This should be make about 2.5 dB
improvement.

Modifications for the Drake are available on the net which dramatically
improve the
unit's performance. I suggest looking sat the site mentioned by Yoshi
JF6BCC.

73, Terry.
----- Original Message -----
From: "Kent" <klandis@woh.rr.com>
To: <amsat-bb@amsat.org>
Sent: 26 October, 2001 01:41
Subject: [amsat-bb] Drake on 122 Mhz


> Hello all
>
> I am new to AO-40 with a converted Drake 2880 using the factory 122 mhz
IF.
> I am hearing the telemetry and qso's but with some difficulty. I'm also
> using the BBQ Grill dish . I'm assuming a pre-amp is in order? Just
> wondering if anyone is having better sucess with a similar setup?  Rig is
> Ft-847.
> Thanks in advance!
>
> Kent  aka N8ZRD
>
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>


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