[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: extra pre-amp



Don,

The UEK-3000 already has 30 dB of gain...you shouldn't need any more. Adding
a preamp after the UEK will not improve sensitivity at all. The basic
sensitivity of your system is set by the front end of the UEK. Make sure you
have as short a connection as possible between the UEK and your 2.4 gig
antenna. Anything more than a foot or so of LMR-400 is TOO MUCH.

With a 24" dish you should hear quite well with the UEK-3000, but you don't
mention the feed? Is it a solid dish? How is it fed? If homebrew, are you
certain the antenna is working up to par?

I'm using a 39" HyperLink Tech BBQ dish with horizontal polarization and the
UEK-3000 and I hear extremely well. I have a base noise level of about S2 on
my FT-847 with internal preamp off, with just the downconverter on...no
passband. I get about 1 S unit of passband noise at low squint angles.

Turning on the internal preamp (which is about the same as adding a preamp
after the UEK-3000) raises the noise floor to S5...and produces not the
slightest improvement in signal to noise...so I don't do it...it's pointless
(and predictable).

If you don't have enough signal from a UEK-3000 there are only a few
potential causes, none of which involve adding a preamp AFTER the UEK:

1. Antenna not working properly.
2. Too much coax loss between Antenna and UEK
3. Defective UEK
4. Incredible loss after the UEK from coax. (affects S-meter but not
sensitivity)

With respect to #4, I initially started with 135' of RG/8X after the UEK and
I still heard wonderfully...of course, I needed the internal preamp in the
FT-847 to make my S-meter go up in the area I wanted...keep in mind, this
didn't change my ability to hear at all...it just made the S-meter more
active.

Hope this helps. 73

hasan schiers, N0AN

schiers@netins.net
or use amsat.org or arrl.net remailer
----- Original Message -----
From: "work" <hair@adelphia.net>
To: "amsat-bb" <amsat-bb@AMSAT.Org>
Sent: Thursday, November 22, 2001 6:14 AM
Subject: [amsat-bb] extra pre-amp


> Can anyone tell me if  putting another pre-amp after the uek-3000 would
help
> increase the audio. Or would that just increase the noise level also.
Using
> a two foot dish. Have a  one meter dish but to heavy for the roof mount.
>
> Don..w2xb
>
>
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>


----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home