We had a similar problem using a Kenwood radio with switching or pin diodes
that was on APRS. The repeater and the APRS radio were on DB224's very close to
each other. The repeater has 6 cans and the aprs had 1 band pass can. Neither
system interfered with the other but we soon discovered we
First of all you do not have enough isolation between antennas with only two
wavelenghts horizonal seperation. A single bandpass cavity will not be enough.
I would try 2 bandpass/bandreject cavities. Reject set for the TX freq and the
other set for the RX freq. I believe that RF from your
Can you receive through a circulator without heavy losses? I've never tried
it...
- Original Message -
From: David
To: Repeater-Builder@yahoogroups.com
Sent: Monday, November 02, 2009 1:31 PM
Subject: [Repeater-Builder] Re: Weird Interference between APRS and 2-M
repeater
:
Can you receive through a circulator without heavy losses? I've never tried
it...
- Original Message -
*From:* David dep...@starband.net
*To:* Repeater-Builder@yahoogroups.com
*Sent:* Monday, November 02, 2009 1:31 PM
*Subject:* [Repeater-Builder] Re: Weird Interference between
:31 PM
Subject: [Repeater-Builder] Re: Weird Interference between APRS and
2-M repeater help needed
First of all you do not have enough isolation between antennas with
only two wavelenghts horizonal seperation. A single bandpass cavity
will not be enough. I would try 2 bandpass/bandreject
On Mon, 2 Nov 2009, dep...@starband.net wrote:
I believe you are right. Simplex is difficult with a circulater.
Can you receive through a circulator without heavy losses? I've never
tried it...
Older Micor mobiles had a built-in circulator and a T/R relay.
--
Kris Kirby, KE4AHR
Only on UHF. VHF was a lowpass filter.
Kris Kirby wrote:
On Mon, 2 Nov 2009, dep...@starband.net mailto:depley%40starband.net
wrote:
I believe you are right. Simplex is difficult with a circulater.
Can you receive through a circulator without heavy losses? I've never
tried it...
At 12:31 PM 11/2/2009, David wrote:
Most people used a simple mobile for aprs which creates alot of
headaches where several transmitters are used. They just dont have
the filtering needed for this application. You should also use a
circulator on your aprs radio. This will help keep RF out of
I am a firm believer that anyone who deploys ANY transmitter on
a mountaintop (or any multi transmitter site) should be shot.
---Darn it.. What I meant is that I am a firm believer that anyone
who deploys ANY transmitter on a mountaintop (or any multi
transmitter site) WITHOUT A
never tried it...
- Original Message -
From: David
To: Repeater-Builder@yahoogroups.com
Sent: Monday, November 02, 2009 1:31 PM
Subject: [Repeater-Builder] Re: Weird Interference between APRS and 2-M
repeater help needed
First of all you do not have enough
I guess there are some sites noisy enough that losing 30 dB wouldn't affect
S/N... ;^)
- Original Message -
From: skipp025
To: Repeater-Builder@yahoogroups.com
Sent: Monday, November 02, 2009 4:29 PM
Subject: [Repeater-Builder] Re: Weird Interference between APRS and 2-M
Thanks for the input folks!
I missed a couple critical pieces of information that are about to get me shot!
;-)
Our FM Voice repeater is running through a 6-cavity duplexer. The APRS setup
had a single cavity, tuned to the 144.39 APRS frequency. I am assuming this
single cavity is acting
Thanks for the input.
I missed a couple critical pieces of information. The FM Voice repeater
is running through a 6-cavity duplexer. The APRS setup had a single
cavity, tuned to the 144.39 APRS frequency. I am assuming this single
cavity is acting as a low pass filter to prevent the voice
Jason Parks wrote:
Noise and desense are one thing, but the popping and crackling when trying to
hook the antenna to a powered
off radio,
I'm assuming that the popping and crackling that you are hearing is on
the active repeater? If so, that is what one can expect if you change
things in
At 04:40 PM 11/2/2009, Joe wrote:
The repeater might be getting into the PA stage of the APRS radio. Try
powering off the APRS radio during the time that you hear the weird
noise. I would bet that the noise goes away as soon as the APRS radio
in powered off.
---Power is irrelevant as the PA
The repeater might be getting into the PA stage of the APRS
radio. Try
powering off the APRS radio during the time that you hear the weird
noise. I would bet that the noise goes away as soon as the APRS radio
in powered off.
What kind of radio is being used for APRS? If it's something
] Re: Weird Interference between APRS and 2-M
repeater help needed
I am a firm believer that anyone who deploys ANY transmitter on
a mountaintop (or any multi transmitter site) should be shot.
---Darn it.. What I meant is that I am a firm believer that anyone
who deploys ANY
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