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Re: false signals-images-harmonics-whatever?




Tracy,

Are you powering it via the coax or a separate line? (the down converter)?

If by a separate line, is it a shielded line? If not....it is a likely cause
of the problem.

I had similar problems when I was using separate power via an unshielded
pair to my UEK-3000. As soon as I changed to RG8-X mini coax for the power
feed, the problem disappeared.

If you are powering it from the coax, try a separate shielded feed (if your
DC permits it...the UEK 3000 gives you the option to use either.)

Also, try getting more physical separation between the TX antenna and the RX
downconverter, if nothing else works.

My problem (severe overload, spurs, fm'ing of the rx signal) all disappeared
immediately upon using a shielded power line.

73,

...hasan


----- Original Message -----
From: "Tracy" <k7kcs@attbi.com>
To: <amsat-bb@AMSAT.Org>
Sent: Thursday, December 27, 2001 11:43 AM
Subject: [amsat-bb] false signals-images-harmonics-whatever?


> Hi all,
>
> I have a Down East Microwave 2400-144RX downconverter.  It works but I am
> receiving many false signals (images?) of my transmitted 435 Mhz signal
(50
> watts) all over the AO-40 passband which makes it hard to hear my real
> signal.  The tranceiver is a IC-910H so I expect it is reasonably clean
and
> 435 does not produce these images on 144.  The 435 antenna is a M2
420-50-11
> yagi 4 feet from the dish which has a helix feed and the downconverter
> mounted directly on the helix.
>
> How do I get rid of these images/signals? Would buying a more expensive
> downconverter (say the SSB electronics UEK-3000) improve things?  In
> general, what do you get for the extra bucks?  Just a little less noise
and
> a few DB gain or more than that?
>
> Thanks for reading this !
>
> 73's  Tracy K7KCS
>
>
> ----
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> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>

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