The situation I was in at the time I experienced this was while
making radio station signal strength measurements from an associate's
vehicle. We were using my laptop with Delorme's Topo USA 7.0 runign
Quad maps and at the same time running a Garmin GPS128 system to
confirm bearing and distance from the transmitter.
I had heard about mutual interference but had never actually had it
happen. In this case we were both having trouble staying
locked. Turning either one of the systems off allowed the other one
to quickly lock and display in DGPS. Turning the other system back
on caused the other one to have severe drop-outs. We were finally
able to resolve the problem by placing the two antennas on opposite
sides of the vehicle.
I'm not sure of the nature of the two receivers, but using
conventional receiver design thinking, the only thing that comes to
mind that might be radiating would be the oscillators or possibly the
I.F. section taling to each other. The antennas were originally
about a foot or two apart so I can't imagine that any first RF tuned
stages could be acting as "Suck-Out Filters" causing a notch to the
other and I can imagine either one re-radiating enough of the bird's
signal to be any problem.
Burt, K6OQK.
From: shali...@gmail.com
Subject: Re: [time-nuts] GPS Antenna -Receiver Mutual Interference...
Content-Type: text/plain
The additional advantage is to give you diversity and some immunity
against multipath (at least it reduces the probability that both
receivers will be affected at the same time due to weird
constellation issues or local interference).
But it now creates an issue which is how do you know who is right
when both receivers don't agree...
Didier KO4BB
Sent from my Verizon Wireless BlackBerry
-----Original Message-----
From: "Rob Kimberley" <r...@timing-consultants.com>
Sender: time-nuts-boun...@febo.com
Date: Mon, 3 Jan 2011 15:59:24
To: 'Discussion of precise time and frequency measurement'<time-nuts@febo.com>
Reply-To: Discussion of precise time and frequency measurement
<time-nuts@febo.com>
Subject: Re: [time-nuts] GPS Antenna -Receiver Mutual Interference...
Yes, I've seen this. On installations in the past, when we were putting up
dual GPS systems, we always put them at least 10 metres apart. What is
actually best practice, is to put one at one end of building and the other
one at the other end.
Rob Kimberley
-----Original Message-----
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark J. Blair
Subject: Re: [time-nuts] GPS Antenna -Receiver Mutual Interference...
On Dec 30, 2010, at 6:53 PM, Burt I. Weiner wrote:
> Has anyone run into a situation where two GPS Navigation type
Antenna/Receivers interfere with each other?
It's possible that LO leakage from one is jamming the other. When doing
mobile GPS receiver testing at work with a single antenna feeding multiple
receivers through a splitter, we sometimes had to insert attenuators in each
receiver's antenna feed to keep them from jamming each other.
--
Mark J. Blair, NF6X <n...@nf6x.net>
Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California U.S.A.
b...@att.net
www.biwa.cc
K6OQK
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
