] On Behalf Of Pointman
Sent: Thursday, November 26, 2009 9:56 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: pre-amp placement
So your suggestion is to get a Band pass/reject cavity instead? Or should I
get 2 for the added isolation?
keep in mind I am on UHF
de
At 11/26/2009 09:39, you wrote:
You might need to add a several DB attenuator
between
the pre amp and the receiver to keep from over
driving
the front end.
Not if you use a good receiver, or not use a preamp with
too much gain.
Bob NO6B
What defines too much gain
At 11/26/2009 10:08, you wrote:
So what is the recommendation to set the loss of the BP cavity? I have a
setting as to 3 db, 1 Db, .5 Db Etc. Running the ARR preamp on a UHF
repeater, it seems the preamp is a little too much and we get a little
desense. I am only running a 4 cavity duplexer
At 11/27/2009 11:14, you wrote:
I would have never considered a dual series RF Preamplifier
layout viable until I'd seen one demonstrated against the
single preamplifier version. The properly installed and
setup dual preamplifier layout with system gain well in excess
of 14dB clearly out preforms
On Nov 27, 2009, at 12:14 PM, skipp025 wrote:
There are Northern California site locations in operation
where the Repeater Rx Antenna System contains the desired
pre-selection, two series pre-amplifiers separated initially
by an adjustable attenuator and later a fixed value. It's
beyond
Hi Skip,
Happy Thanksgiving first off. Go to the Angle Linear web site and read
Chip's documentation he has provided. I don't know too many people that has
a better product than him and his stuff if installed correctly works like no
other.
Mike Mullarkey K7PFJ
From:
Skipp,
It seems as if both of your answers suggest that the preamp be installed in
the same place- between the duplexer and the bandpass cavity. Perhaps your
intent for the second situation was to suggest that the preamp be placed
between the bandpass cavity and the receiver input. The site
The main way of thinking is that you want to put the pre-amp after the band
pass filter.
The reason for this is that if it is before the b/p filter, it amps anything it
sees, noise and unwanted stuff alike.
If its behind the b/p filter, it only amps the signals that are left and need
it.
You
Anyone have a spare bandpass filter tunable for the UHF amateur band like a DCI?
Thanks!
Alan
- Original Message -
From: Mike Dietrich
To: Repeater-Builder@yahoogroups.com
Sent: Thursday, November 26, 2009 10:09 AM
Subject: Re: [Repeater-Builder] Re: pre-amp placement
At 11/26/2009 07:31, you wrote:
Mike Dietrich m.dietr...@... wrote:
The main way of thinking is that you want to put the
pre-amp after the band pass filter.
The reason for this is that if it is before the b/p
filter, it amps anything it sees, noise and unwanted
stuff alike. If its
At 11/26/2009 08:14, you wrote:
Thanks Glenn,
I think I will it where it is since it is a Adv Receiver Research Gasfed.
Good choice IMO. If you want to maximize your sensitivity, just make sure
your pass cavity is very low loss. If the loops are or adjusted for 2 dB
loss, you could easily
You might need to add a several DB attenuator
between
the pre amp and the receiver to keep from over
driving
the front end.
Not if you use a good receiver, or not use a preamp with
too much gain.
Bob NO6B
What defines too much gain can vary wildly. One trick I learned in
At 11/26/2009 08:30, you wrote:
Ralph you bring up a good point of thought.
The ham that built our repeater placed the Decibel Products 4002 Bandpass
behind the Wacom 6 can duplexer and then followed by the ARR Gasfed
P144VDG to the radio.
Now where he built it was his tower site (an old ATT
.
de KM3W
From: n...@no6b.com n...@no6b.com
To: Repeater-Builder@yahoogroups.com
Sent: Thu, November 26, 2009 12:50:18 PM
Subject: Re: [Repeater-Builder] Re: pre-amp placement
At 11/26/2009 08:30, you wrote:
Ralph you bring up a good point of thought.
The ham that built our repeater placed
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: pre-amp placement
So what is the recommendation to set the loss of the BP cavity? I have a
setting as to 3 dB, 1 dB, .5 dB etc. Running the ARR preamp on a UHF
repeater, it seems the preamp is a little too much and we get
Of Mel Swanberg
Sent: Thursday, November 26, 2009 12:40 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: pre-amp placement
You might need to add a several DB attenuator
between
the pre amp and the receiver to keep from over
driving
the front end
Subject: RE: [Repeater-Builder] Re: pre-amp placement
A total insertion loss of about 1.0 dB works well, in my experience. With
two 8 bandpass cavities in series, this gives at least 25 dB of isolation
from the transmitter carrier at a 600 kHz split.
Bear in mind that your notch cavity has
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