Antenna amplifier question

Antenna amplifier question

Post by 123 » Sat, 13 Sep 2003 08:46:43

Why wouldn't I want to do this?
I would like to purchase an amplifier for my scanner antenna. I saw a
cable tv amplifier with 10db gain for the frequencies 10 - 900 mhz.
Why wouldn't this work; or would it?
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Antenna amplifier question

Post by GrtPmpkin » Sat, 13 Sep 2003 09:07:35


Quote:>Why wouldn't I want to do this?

Possible reasons would include having enough intermod/bleed/noise on your
scanner as it is BEFORE adding the amplifier, in which case the amp would only
make it a lot worse. Also, if you have some noise but not much, but the amp
will boost signals below 30 MHz, you may find some added interference from
signals in that region.
IF it boosts FM freq's as well, you have that to deal with.
That said, though, if you already have a fairly clean system and just want a
bit of a kicker in receiving fringe stations, etc., there's no reason it
shouldn't improve things overall.
Just make sure you place it AT the antenna, not at the scanner... you want to
boost as much signal as you can BEFORE the noise added along the feedline, etc.
Good luck-
Linus
 
 
 

Antenna amplifier question

Post by George » Sat, 13 Sep 2003 09:42:20


> Why wouldn't I want to do this?
> I would like to purchase an amplifier for my scanner antenna. I saw a
> cable tv amplifier with 10db gain for the frequencies 10 - 900 mhz.
> Why wouldn't this work; or would it?
> Remove the "123" in my address to reply by email!

It will work, if you go here:
http://www.milaircomms.com/antenna_mounted_amplifier.html  you'll see an
article I wrote about my experiences about using a TV amp.  In the
article I used an Antenna mounted amp.

I've also used a wideband amp for receiving Military Satellites in the
260 MHz range.  You can see this at:
http://www.milaircomms.com/shack.html just scroll down until you see my
Handheld and homemade 5 element Yagi.

In short if you do it rigth it will work wonders.   If you add it and
start picking up FM Overload and Intermod you might want to invest in
some filters.  Depending on what I want to hear and the direction I aim
my beam I will have some problems.  However once I insert my Hi Pass
Stridsberg Filter 99% of my problems go away.  The HiPass filter I'm
using will block signals below 225 MHz.  Since 99% of my listening is
MilAir this is perfect.

George
http://www.MilAirComms.com

 
 
 

Antenna amplifier question

Post by 123 » Sat, 13 Sep 2003 12:05:32

I basically am interested in only trying to bring in one signal that's
just a bit out of reach. Thanks for all the info.


Quote:>>Why wouldn't I want to do this?

>Possible reasons would include having enough intermod/bleed/noise on your
>scanner as it is BEFORE adding the amplifier, in which case the amp would only
>make it a lot worse. Also, if you have some noise but not much, but the amp
>will boost signals below 30 MHz, you may find some added interference from
>signals in that region.
>IF it boosts FM freq's as well, you have that to deal with.
>That said, though, if you already have a fairly clean system and just want a
>bit of a kicker in receiving fringe stations, etc., there's no reason it
>shouldn't improve things overall.
>Just make sure you place it AT the antenna, not at the scanner... you want to
>boost as much signal as you can BEFORE the noise added along the feedline, etc.
>Good luck-
>Linus

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Antenna amplifier question

Post by 123 » Sat, 13 Sep 2003 12:06:56

Thanks for the info. I enjoyed your article. I noticed you use a
Scantenna. How do you like it? Any pluses or minuses you could give
me?

On Thu, 11 Sep 2003 20:42:20 -0400, GeorgeF



>> Why wouldn't I want to do this?
>> I would like to purchase an amplifier for my scanner antenna. I saw a
>> cable tv amplifier with 10db gain for the frequencies 10 - 900 mhz.
>> Why wouldn't this work; or would it?
>> Remove the "123" in my address to reply by email!

>It will work, if you go here:
>http://www.milaircomms.com/antenna_mounted_amplifier.html  you'll see an
>article I wrote about my experiences about using a TV amp.  In the
>article I used an Antenna mounted amp.

>I've also used a wideband amp for receiving Military Satellites in the
>260 MHz range.  You can see this at:
>http://www.milaircomms.com/shack.html just scroll down until you see my
>Handheld and homemade 5 element Yagi.

>In short if you do it rigth it will work wonders.   If you add it and
>start picking up FM Overload and Intermod you might want to invest in
>some filters.  Depending on what I want to hear and the direction I aim
>my beam I will have some problems.  However once I insert my Hi Pass
>Stridsberg Filter 99% of my problems go away.  The HiPass filter I'm
>using will block signals below 225 MHz.  Since 99% of my listening is
>MilAir this is perfect.

>George
>http://www.MilAirComms.com

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Antenna amplifier question

Post by George » Sat, 13 Sep 2003 12:30:23


> Thanks for the info. I enjoyed your article. I noticed you use a
> Scantenna. How do you like it? Any pluses or minuses you could give
> me?

I love my ScanTenna.  In fact using a combination of two Stridesburg
Amplified Multicouplers (seen here:
http://www.milaircomms.com/review_stridsberg_mca204.html) it drives 11
of the 19 scanners in the shack.

I can't think of any minuses at all.  It is a non-dirctional antenna, so
if you have interference in the area you can NOT null it out by rotating
the ant in a different direction.  Because of that I don't use a pre-amp
on the ScanTenna.  However I've had many non-directional antenna
including $110 discones.  The ScanTenna puts any discone to shame...

About the only think I've found that is better than the ScanTenna would
be beams such as the ScannerBeam or the Create Log P.

you might want to try a ScannerBeam (found at
http://www.AntennaWarehouse.com) to receive that one signal you're
trying to get.  You might have better luck doing that, and if that still
doesn't work then add a pre-amp to the ScannerBeam.   If you try to add
a pre-amp to a non-directional antenna you'll increase your chances at
picking up FM overload and other interference related problems.  Not
saying it won't work but saying your chances will be better with a beam.

George
http://www.MilAirComms.com

 
 
 

Antenna amplifier question

Post by 123 » Sun, 14 Sep 2003 04:01:22

What's the difference between an amplified multicoupler and an
amplifier?

On Thu, 11 Sep 2003 23:30:23 -0400, GeorgeF



>> Thanks for the info. I enjoyed your article. I noticed you use a
>> Scantenna. How do you like it? Any pluses or minuses you could give
>> me?

>I love my ScanTenna.  In fact using a combination of two Stridesburg
>Amplified Multicouplers (seen here:
>http://www.milaircomms.com/review_stridsberg_mca204.html) it drives 11
>of the 19 scanners in the shack.

>I can't think of any minuses at all.  It is a non-dirctional antenna, so
>if you have interference in the area you can NOT null it out by rotating
>the ant in a different direction.  Because of that I don't use a pre-amp
>on the ScanTenna.  However I've had many non-directional antenna
>including $110 discones.  The ScanTenna puts any discone to shame...

>About the only think I've found that is better than the ScanTenna would
>be beams such as the ScannerBeam or the Create Log P.

>you might want to try a ScannerBeam (found at
>http://www.AntennaWarehouse.com) to receive that one signal you're
>trying to get.  You might have better luck doing that, and if that still
>doesn't work then add a pre-amp to the ScannerBeam.   If you try to add
>a pre-amp to a non-directional antenna you'll increase your chances at
>picking up FM overload and other interference related problems.  Not
>saying it won't work but saying your chances will be better with a beam.

>George
>http://www.MilAirComms.com

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Antenna amplifier question

Post by George » Sun, 14 Sep 2003 04:07:49


> What's the difference between an amplified multicoupler and an
> amplifier?

The amplified Multicoupler only has a 4 dB amp, just enought to overcome
the looses of the multicoulper itself.  You can buy an un-amplified
multicoupler however each scanner connected would experience a 3dB loose
in signal.

A pre-amp is an amplified designed to actually increase signal, usually
10 dB - 30 dB.

George
http://www.MilAircomms.com

 
 
 

Antenna amplifier question

Post by S-Mete » Sun, 14 Sep 2003 05:12:30

FWIW, if you can get you antenna higher, that might help. If the signal
flying is heading for outer space, you won't hear it any better with an
amplifier. If getting the antenna a few feet higher will help, it might be
worth a shot. Just use high quality coax to minimise loss.
 
 
 

Antenna amplifier question

Post by john wilso » Sun, 25 Jan 2004 07:11:54

  Mainly because the noise factor is too high, the frequency range too
broad and the initial amplification would not be at the antenna but at
the other end of the coax.  Signal losses occur from the antenna to the
amplifier.   Bad idea.

> Why wouldn't I want to do this?
> I would like to purchase an amplifier for my scanner antenna. I saw a
> cable tv amplifier with 10db gain for the frequencies 10 - 900 mhz.
> Why wouldn't this work; or would it?
> Remove the "123" in my address to reply by email!

 
 
 

Antenna amplifier question

Post by john wilso » Sun, 25 Jan 2004 07:19:30

   I have 6 Scantennas tower mounted at 125 ft.  They are pre-amped with the
RS VHF/UHF TV mast mounted amp.  They work great for a broad banded antenna
from 25-800 mhz.  The performance in the 406-420 mhz. range is not as good as
the other frequency ranges, but it is ok.  I highly
recommend them.  I use RG-6 coax cable for a feedline.  I have been using
Scantennas for over 15 years.  I have tried many different antenna
configurations, to include custom made yagis, etc., and the Scantenna always
outperformed the others.  The Scantennas are somewhat directional.  They are
ugly to look at but they do the job.  I consistently hear a NOAA broadcast on
162.525 mhz. from State College, Pa.  State College, Pa. is approximately 225
air miles north of my central Va. location.  I have dedicated
scanners/receivers for different frequency ranges of monitoring interest.
Grove Enterprises sells the Scantenna.

> Thanks for the info. I enjoyed your article. I noticed you use a
> Scantenna. How do you like it? Any pluses or minuses you could give
> me?

> On Thu, 11 Sep 2003 20:42:20 -0400, GeorgeF


> >> Why wouldn't I want to do this?
> >> I would like to purchase an amplifier for my scanner antenna. I saw a
> >> cable tv amplifier with 10db gain for the frequencies 10 - 900 mhz.
> >> Why wouldn't this work; or would it?
> >> Remove the "123" in my address to reply by email!

> >It will work, if you go here:
> >http://www.milaircomms.com/antenna_mounted_amplifier.html  you'll see an
> >article I wrote about my experiences about using a TV amp.  In the
> >article I used an Antenna mounted amp.

> >I've also used a wideband amp for receiving Military Satellites in the
> >260 MHz range.  You can see this at:
> >http://www.milaircomms.com/shack.html just scroll down until you see my
> >Handheld and homemade 5 element Yagi.

> >In short if you do it rigth it will work wonders.   If you add it and
> >start picking up FM Overload and Intermod you might want to invest in
> >some filters.  Depending on what I want to hear and the direction I aim
> >my beam I will have some problems.  However once I insert my Hi Pass
> >Stridsberg Filter 99% of my problems go away.  The HiPass filter I'm
> >using will block signals below 225 MHz.  Since 99% of my listening is
> >MilAir this is perfect.

> >George
> >http://www.MilAirComms.com

> Remove the "123" in my address to reply by email!

 
 
 

Antenna amplifier question

Post by Steve Ston » Mon, 26 Jan 2004 08:06:37

My biggest problem with TV preamps, mast mounted or not is local overload
from poorly attended to paging transmitters.

I could null them out with a directional antenna but I sure would loose alot
of listening fun from my west.

Many years ago I took a Pro-34 on board a flight to Memphis (had permission
from the crew to use it). Once we got a few thousand feet in the air the
scanner was unusable. Just too much of a good thing and too many signals all
over the place.
--

>> Remove "zz" from e-mail address to direct reply. <<



Quote:>    I have 6 Scantennas tower mounted at 125 ft.  They are pre-amped with
the
> RS VHF/UHF TV mast mounted amp.  They work great for a broad banded
antenna
> from 25-800 mhz.  The performance in the 406-420 mhz. range is not as good
as
> the other frequency ranges, but it is ok.  I highly
> recommend them.  I use RG-6 coax cable for a feedline.  I have been using
> Scantennas for over 15 years.  I have tried many different antenna
> configurations, to include custom made yagis, etc., and the Scantenna
always
> outperformed the others.  The Scantennas are somewhat directional.  They
are
> ugly to look at but they do the job.  I consistently hear a NOAA broadcast
on
> 162.525 mhz. from State College, Pa.  State College, Pa. is approximately
225
> air