JR
Jason Rabel
Fri, Sep 30, 2011 1:44 PM
Please don't start a political discussion, I just have a SIMPLE TECHNICAL QUESTION that I'm hoping someone can answer (and I don't
think it was discussed in the past).
In all the stuff I've glanced over about L2, they talk about better filtering for GPS modules to eliminate the interference issue.
Likewise they talk about potential replacement of existing hardware and such because of poor filtering that overlaps into other
frequencies...
My question is...
To filter out the L2 signal, would an actual GPS receiver have to be replaced / modified?
Or would a more simple and cheaper alternative be to get a new antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy? Is that technically possible or does it have to be on the receiver?
Or even something in-line where I wouldn't have to replace either my antenna or receivers... It would just look like an attenuator
that you stick somewhere along the cable?
Okay... so three part question, nothing more, nothing less...
Please don't start a political discussion, I just have a SIMPLE TECHNICAL QUESTION that I'm hoping someone can answer (and I don't
think it was discussed in the past).
In all the stuff I've glanced over about L2, they talk about better filtering for GPS modules to eliminate the interference issue.
Likewise they talk about potential replacement of existing hardware and such because of poor filtering that overlaps into other
frequencies...
My question is...
To filter out the L2 signal, would an actual GPS receiver have to be replaced / modified?
Or would a more simple and cheaper alternative be to get a new antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy? Is that technically possible or does it have to be on the receiver?
Or even something in-line where I wouldn't have to replace either my antenna or receivers... It would just look like an attenuator
that you stick somewhere along the cable?
Okay... so three part question, nothing more, nothing less...
JL
Jim Lux
Fri, Sep 30, 2011 2:01 PM
On 9/30/11 6:44 AM, Jason Rabel wrote:
Please don't start a political discussion, I just have a SIMPLE TECHNICAL QUESTION that I'm hoping someone can answer (and I don't
think it was discussed in the past).
In all the stuff I've glanced over about L2, they talk about better filtering for GPS modules to eliminate the interference issue.
Likewise they talk about potential replacement of existing hardware and such because of poor filtering that overlaps into other
frequencies...
My question is...
To filter out the L2 signal, would an actual GPS receiver have to be replaced / modified?
Or would a more simple and cheaper alternative be to get a new antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy? Is that technically possible or does it have to be on the receiver?
Yes
for that matter one could do fancy antennas that place a null on the
interfering source.
Or even something in-line where I wouldn't have to replace either my antenna or receivers... It would just look like an attenuator
that you stick somewhere along the cable?
Yes
everything is a compromise, of course. A filter that rejects frequency
A doesn't usually have zero loss at frequency B; ditto fancy antenna
designs.
If the interfering signal is strong enough, you won't be able to have an
LNA right after the antenna, because the LNA will saturate. (this is
the potential problem with your "in line" alternative)
The real issue is that these solutions take care of a fairly small
fraction of the total GPS receiver population (e.g. it works ok for
fixed timing receivers, but not so hot for size, power, weight sensitive
applications)
They're also, potentially, fairly expensive in the aggregate ($100 of
filters for 10 million GPS receivers is getting into serious budgetary
area. And there's a lot more than 10 million receivers out there... I
could believe 100 million, but probably not a billion)
On 9/30/11 6:44 AM, Jason Rabel wrote:
> Please don't start a political discussion, I just have a SIMPLE TECHNICAL QUESTION that I'm hoping someone can answer (and I don't
> think it was discussed in the past).
>
> In all the stuff I've glanced over about L2, they talk about better filtering for GPS modules to eliminate the interference issue.
> Likewise they talk about potential replacement of existing hardware and such because of poor filtering that overlaps into other
> frequencies...
>
> My question is...
>
> To filter out the L2 signal, would an actual GPS receiver have to be replaced / modified?
No
>
> Or would a more simple and cheaper alternative be to get a new antenna (with fancy filtering) to replace my existing roof-top
> antenna and expect all my old equipment to be happy? Is that technically possible or does it have to be on the receiver?
>
Yes
for that matter one could do fancy antennas that place a null on the
interfering source.
> Or even something in-line where I wouldn't have to replace either my antenna or receivers... It would just look like an attenuator
> that you stick somewhere along the cable?
>
Yes
---
everything is a compromise, of course. A filter that rejects frequency
A doesn't usually have zero loss at frequency B; ditto fancy antenna
designs.
If the interfering signal is strong enough, you won't be able to have an
LNA right after the antenna, because the LNA will saturate. (this is
the potential problem with your "in line" alternative)
The real issue is that these solutions take care of a fairly small
fraction of the total GPS receiver population (e.g. it works ok for
fixed timing receivers, but not so hot for size, power, weight sensitive
applications)
They're also, potentially, fairly expensive in the aggregate ($100 of
filters for 10 million GPS receivers is getting into serious budgetary
area. And there's a lot more than 10 million receivers out there... I
could believe 100 million, but probably not a billion)
MI
Marco IK1ODO -2
Fri, Sep 30, 2011 2:02 PM
At 15:44 30-09-11, Jason wrote:
To filter out the L2 signal, would an actual GPS receiver have to be
replaced / modified?
Or would a more simple and cheaper alternative be to get a new
antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy?
I think that a new antenna/filter/amplifier unit would be ok. But the
problem is the installed base of receivers, including all those
costly units used for geodesy or navigation, that have embedded
antennas. Those will be hard to modify.
73 - Marco IK1ODO
At 15:44 30-09-11, Jason wrote:
>To filter out the L2 signal, would an actual GPS receiver have to be
>replaced / modified?
>
>Or would a more simple and cheaper alternative be to get a new
>antenna (with fancy filtering) to replace my existing roof-top
>antenna and expect all my old equipment to be happy?
I think that a new antenna/filter/amplifier unit would be ok. But the
problem is the installed base of receivers, including all those
costly units used for geodesy or navigation, that have embedded
antennas. Those will be hard to modify.
73 - Marco IK1ODO
BB
Bob Bownes
Fri, Sep 30, 2011 2:49 PM
Right. The fixed location apps are not all that hard. But the mobile
ones are going to be a big problem.
Not to mention getting them certified for the application. The GPS you
have in your car is not certified for life critical applications. The
one I have in my ambulance is. And let's not even get into commercial
flight certification. A technical issue, but one verging on politics.
To answer your question #3, it is one of two specific kinds of
attenuator. Generally a band-pass (passes the GPS frequency only) or
notch filter (attenuates the undesired frequency only). As Jim said,
these things don't only impact the desired frequency. For more
information, take a look here:
http://en.wikipedia.org/wiki/Band-pass_filter
Short answer, yes it can be done, in a limited set of applications.
Until you reach layer 8.
Bob
On Fri, Sep 30, 2011 at 10:02 AM, Marco IK1ODO -2 ik1odo@spin-it.com wrote:
At 15:44 30-09-11, Jason wrote:
To filter out the L2 signal, would an actual GPS receiver have to be
replaced / modified?
Or would a more simple and cheaper alternative be to get a new antenna
(with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy?
I think that a new antenna/filter/amplifier unit would be ok. But the
problem is the installed base of receivers, including all those costly units
used for geodesy or navigation, that have embedded antennas. Those will be
hard to modify.
73 - Marco IK1ODO
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.
Right. The fixed location apps are not all that hard. But the mobile
ones are going to be a big problem.
Not to mention getting them certified for the application. The GPS you
have in your car is not certified for life critical applications. The
one I have in my ambulance is. And let's not even get into commercial
flight certification. A technical issue, but one verging on politics.
To answer your question #3, it is one of two specific kinds of
attenuator. Generally a band-pass (passes the GPS frequency only) or
notch filter (attenuates the undesired frequency only). As Jim said,
these things don't only impact the desired frequency. For more
information, take a look here:
http://en.wikipedia.org/wiki/Band-pass_filter
Short answer, yes it can be done, in a limited set of applications.
Until you reach layer 8.
Bob
On Fri, Sep 30, 2011 at 10:02 AM, Marco IK1ODO -2 <ik1odo@spin-it.com> wrote:
> At 15:44 30-09-11, Jason wrote:
>
>> To filter out the L2 signal, would an actual GPS receiver have to be
>> replaced / modified?
>>
>> Or would a more simple and cheaper alternative be to get a new antenna
>> (with fancy filtering) to replace my existing roof-top
>> antenna and expect all my old equipment to be happy?
>
> I think that a new antenna/filter/amplifier unit would be ok. But the
> problem is the installed base of receivers, including all those costly units
> used for geodesy or navigation, that have embedded antennas. Those will be
> hard to modify.
>
> 73 - Marco IK1ODO
>
>
>
> _______________________________________________
> 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.
>
CF
Chuck Forsberg WA7KGX N2469R
Fri, Sep 30, 2011 2:55 PM
If LightSquared deploys their high powered LTE network in the satellite band
the GPS world will become very interesting indeed. Are LightSquared willing
to spend $20,000 to upgrade the GPS on my Skylane to a new model which
does not yet exist?
With that many transmitters we may experience areas where RF from multiple
high power transmitters creates hot spots. In some places pieces of metal
with non Ohmic bonds will create mixing products, some of which may fall
directly within GPS bands. These effects have not been simulated.
Who knows who the FCC is listening to - the GPS industry including millions
of current users, or those who appear to have bought under the table favor.
This could make Solyndra look like small change. Film at 11.
On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
At 15:44 30-09-11, Jason wrote:
To filter out the L2 signal, would an actual GPS receiver have to be
replaced / modified?
Or would a more simple and cheaper alternative be to get a new
antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy?
I think that a new antenna/filter/amplifier unit would be ok. But the
problem is the installed base of receivers, including all those costly
units used for geodesy or navigation, that have embedded antennas.
Those will be hard to modify.
73 - Marco IK1ODO
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.
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
If LightSquared deploys their high powered LTE network in the satellite band
the GPS world will become very interesting indeed. Are LightSquared willing
to spend $20,000 to upgrade the GPS on my Skylane to a new model which
does not yet exist?
With that many transmitters we may experience areas where RF from multiple
high power transmitters creates hot spots. In some places pieces of metal
with non Ohmic bonds will create mixing products, some of which may fall
directly within GPS bands. These effects have not been simulated.
Who knows who the FCC is listening to - the GPS industry including millions
of current users, or those who appear to have bought under the table favor.
This could make Solyndra look like small change. Film at 11.
On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
> At 15:44 30-09-11, Jason wrote:
>
>> To filter out the L2 signal, would an actual GPS receiver have to be
>> replaced / modified?
>>
>> Or would a more simple and cheaper alternative be to get a new
>> antenna (with fancy filtering) to replace my existing roof-top
>> antenna and expect all my old equipment to be happy?
>
> I think that a new antenna/filter/amplifier unit would be ok. But the
> problem is the installed base of receivers, including all those costly
> units used for geodesy or navigation, that have embedded antennas.
> Those will be hard to modify.
>
> 73 - Marco IK1ODO
>
>
>
> _______________________________________________
> 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.
>
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
L
lists@lazygranch.com
Fri, Sep 30, 2011 3:09 PM
Why are we rehashing Light Squared again?
Solyndra...eh, the cost of one day of war...the important thing is where is the real birth certificate! ;-)
-----Original Message-----
From: Chuck Forsberg WA7KGX N2469R caf@omen.com
Sender: time-nuts-bounces@febo.com
Date: Fri, 30 Sep 2011 07:55:24
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] GPS Interference Question
If LightSquared deploys their high powered LTE network in the satellite band
the GPS world will become very interesting indeed. Are LightSquared willing
to spend $20,000 to upgrade the GPS on my Skylane to a new model which
does not yet exist?
With that many transmitters we may experience areas where RF from multiple
high power transmitters creates hot spots. In some places pieces of metal
with non Ohmic bonds will create mixing products, some of which may fall
directly within GPS bands. These effects have not been simulated.
Who knows who the FCC is listening to - the GPS industry including millions
of current users, or those who appear to have bought under the table favor.
This could make Solyndra look like small change. Film at 11.
On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
At 15:44 30-09-11, Jason wrote:
To filter out the L2 signal, would an actual GPS receiver have to be
replaced / modified?
Or would a more simple and cheaper alternative be to get a new
antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy?
I think that a new antenna/filter/amplifier unit would be ok. But the
problem is the installed base of receivers, including all those costly
units used for geodesy or navigation, that have embedded antennas.
Those will be hard to modify.
73 - Marco IK1ODO
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.
Why are we rehashing Light Squared again?
Solyndra...eh, the cost of one day of war...the important thing is where is the real birth certificate! ;-)
-----Original Message-----
From: Chuck Forsberg WA7KGX N2469R <caf@omen.com>
Sender: time-nuts-bounces@febo.com
Date: Fri, 30 Sep 2011 07:55:24
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 Interference Question
If LightSquared deploys their high powered LTE network in the satellite band
the GPS world will become very interesting indeed. Are LightSquared willing
to spend $20,000 to upgrade the GPS on my Skylane to a new model which
does not yet exist?
With that many transmitters we may experience areas where RF from multiple
high power transmitters creates hot spots. In some places pieces of metal
with non Ohmic bonds will create mixing products, some of which may fall
directly within GPS bands. These effects have not been simulated.
Who knows who the FCC is listening to - the GPS industry including millions
of current users, or those who appear to have bought under the table favor.
This could make Solyndra look like small change. Film at 11.
On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
> At 15:44 30-09-11, Jason wrote:
>
>> To filter out the L2 signal, would an actual GPS receiver have to be
>> replaced / modified?
>>
>> Or would a more simple and cheaper alternative be to get a new
>> antenna (with fancy filtering) to replace my existing roof-top
>> antenna and expect all my old equipment to be happy?
>
> I think that a new antenna/filter/amplifier unit would be ok. But the
> problem is the installed base of receivers, including all those costly
> units used for geodesy or navigation, that have embedded antennas.
> Those will be hard to modify.
>
> 73 - Marco IK1ODO
>
>
>
> _______________________________________________
> 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.
>
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
_______________________________________________
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.
TH
Tom Holmes
Fri, Sep 30, 2011 3:10 PM
Sticking with the intent to keep this non-political, what good is a filter
if the offending signal is within the necessary passband?
Tom Holmes, N8ZM
Tipp City, OH
EM79
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Chuck Forsberg WA7KGX N2469R
Sent: Friday, September 30, 2011 10:55 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS Interference Question
If LightSquared deploys their high powered LTE network in the satellite
the GPS world will become very interesting indeed. Are LightSquared
to spend $20,000 to upgrade the GPS on my Skylane to a new model which
does not yet exist?
With that many transmitters we may experience areas where RF from multiple
high power transmitters creates hot spots. In some places pieces of metal
with non Ohmic bonds will create mixing products, some of which may fall
directly within GPS bands. These effects have not been simulated.
Who knows who the FCC is listening to - the GPS industry including
of current users, or those who appear to have bought under the table
This could make Solyndra look like small change. Film at 11.
On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
At 15:44 30-09-11, Jason wrote:
To filter out the L2 signal, would an actual GPS receiver have to be
replaced / modified?
Or would a more simple and cheaper alternative be to get a new
antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy?
I think that a new antenna/filter/amplifier unit would be ok. But the
problem is the installed base of receivers, including all those costly
units used for geodesy or navigation, that have embedded antennas.
Those will be hard to modify.
73 - Marco IK1ODO
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.
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
Sticking with the intent to keep this non-political, what good is a filter
if the offending signal is within the necessary passband?
Tom Holmes, N8ZM
Tipp City, OH
EM79
> -----Original Message-----
> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
> Behalf Of Chuck Forsberg WA7KGX N2469R
> Sent: Friday, September 30, 2011 10:55 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] GPS Interference Question
>
> If LightSquared deploys their high powered LTE network in the satellite
band
> the GPS world will become very interesting indeed. Are LightSquared
willing
> to spend $20,000 to upgrade the GPS on my Skylane to a new model which
> does not yet exist?
>
> With that many transmitters we may experience areas where RF from multiple
> high power transmitters creates hot spots. In some places pieces of metal
> with non Ohmic bonds will create mixing products, some of which may fall
> directly within GPS bands. These effects have not been simulated.
>
> Who knows who the FCC is listening to - the GPS industry including
millions
> of current users, or those who appear to have bought under the table
favor.
> This could make Solyndra look like small change. Film at 11.
>
>
> On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
> > At 15:44 30-09-11, Jason wrote:
> >
> >> To filter out the L2 signal, would an actual GPS receiver have to be
> >> replaced / modified?
> >>
> >> Or would a more simple and cheaper alternative be to get a new
> >> antenna (with fancy filtering) to replace my existing roof-top
> >> antenna and expect all my old equipment to be happy?
> >
> > I think that a new antenna/filter/amplifier unit would be ok. But the
> > problem is the installed base of receivers, including all those costly
> > units used for geodesy or navigation, that have embedded antennas.
> > Those will be hard to modify.
> >
> > 73 - Marco IK1ODO
> >
> >
> >
> > _______________________________________________
> > 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.
> >
>
> --
> Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
> Developer of Industrial ZMODEM(Tm) for Embedded Applications
> Omen Technology Inc "The High Reliability Software"
> 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
>
>
> _______________________________________________
> 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.
CA
Chris Albertson
Fri, Sep 30, 2011 3:11 PM
Please don't start a political discussion, I just have a SIMPLE TECHNICAL QUESTION that I'm hoping someone can answer (and I don't
think it was discussed in the past).
In all the stuff I've glanced over about L2, they talk about better filtering for GPS modules to eliminate the interference issue.
Likewise they talk about potential replacement of existing hardware and such because of poor filtering that overlaps into other
frequencies...
My question is...
To filter out the L2 signal, would an actual GPS receiver have to be replaced / modified?
In theory no. but practically most devices that use GPS have a
built-in antenna. For example, your cell phone, How would you add a
filter to a cel phone. I L2 really going to pay to replace every
Apple iPhone on Earth, and every automotive GPS system.
Yes one could in theory change out the antenna in sone kinds of GPSes
that have external antenna but those systems are in the minority
Chris Albertson
Redondo Beach, California
On Fri, Sep 30, 2011 at 6:44 AM, Jason Rabel
<jason@extremeoverclocking.com> wrote:
> Please don't start a political discussion, I just have a SIMPLE TECHNICAL QUESTION that I'm hoping someone can answer (and I don't
> think it was discussed in the past).
>
> In all the stuff I've glanced over about L2, they talk about better filtering for GPS modules to eliminate the interference issue.
> Likewise they talk about potential replacement of existing hardware and such because of poor filtering that overlaps into other
> frequencies...
>
> My question is...
>
> To filter out the L2 signal, would an actual GPS receiver have to be replaced / modified?
In theory no. but practically most devices that use GPS have a
built-in antenna. For example, your cell phone, How would you add a
filter to a cel phone. I L2 really going to pay to replace every
Apple iPhone on Earth, and every automotive GPS system.
Yes one could in theory change out the antenna in sone kinds of GPSes
that have external antenna but those systems are in the minority
--
Chris Albertson
Redondo Beach, California
BB
Bob Bownes
Fri, Sep 30, 2011 3:11 PM
Exactly. The narrower the filter, the more it will cost. In general.
On Fri, Sep 30, 2011 at 11:10 AM, Tom Holmes tholmes@woh.rr.com wrote:
Sticking with the intent to keep this non-political, what good is a filter
if the offending signal is within the necessary passband?
Tom Holmes, N8ZM
Tipp City, OH
EM79
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Chuck Forsberg WA7KGX N2469R
Sent: Friday, September 30, 2011 10:55 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS Interference Question
If LightSquared deploys their high powered LTE network in the satellite
the GPS world will become very interesting indeed. Are LightSquared
to spend $20,000 to upgrade the GPS on my Skylane to a new model which
does not yet exist?
With that many transmitters we may experience areas where RF from multiple
high power transmitters creates hot spots. In some places pieces of metal
with non Ohmic bonds will create mixing products, some of which may fall
directly within GPS bands. These effects have not been simulated.
Who knows who the FCC is listening to - the GPS industry including
of current users, or those who appear to have bought under the table
This could make Solyndra look like small change. Film at 11.
On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
At 15:44 30-09-11, Jason wrote:
To filter out the L2 signal, would an actual GPS receiver have to be
replaced / modified?
Or would a more simple and cheaper alternative be to get a new
antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy?
I think that a new antenna/filter/amplifier unit would be ok. But the
problem is the installed base of receivers, including all those costly
units used for geodesy or navigation, that have embedded antennas.
Those will be hard to modify.
73 - Marco IK1ODO
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.
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
Exactly. The narrower the filter, the more it will cost. In general.
On Fri, Sep 30, 2011 at 11:10 AM, Tom Holmes <tholmes@woh.rr.com> wrote:
> Sticking with the intent to keep this non-political, what good is a filter
> if the offending signal is within the necessary passband?
>
> Tom Holmes, N8ZM
> Tipp City, OH
> EM79
>
>
>> -----Original Message-----
>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
>> Behalf Of Chuck Forsberg WA7KGX N2469R
>> Sent: Friday, September 30, 2011 10:55 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] GPS Interference Question
>>
>> If LightSquared deploys their high powered LTE network in the satellite
> band
>> the GPS world will become very interesting indeed. Are LightSquared
> willing
>> to spend $20,000 to upgrade the GPS on my Skylane to a new model which
>> does not yet exist?
>>
>> With that many transmitters we may experience areas where RF from multiple
>> high power transmitters creates hot spots. In some places pieces of metal
>> with non Ohmic bonds will create mixing products, some of which may fall
>> directly within GPS bands. These effects have not been simulated.
>>
>> Who knows who the FCC is listening to - the GPS industry including
> millions
>> of current users, or those who appear to have bought under the table
> favor.
>> This could make Solyndra look like small change. Film at 11.
>>
>>
>> On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
>> > At 15:44 30-09-11, Jason wrote:
>> >
>> >> To filter out the L2 signal, would an actual GPS receiver have to be
>> >> replaced / modified?
>> >>
>> >> Or would a more simple and cheaper alternative be to get a new
>> >> antenna (with fancy filtering) to replace my existing roof-top
>> >> antenna and expect all my old equipment to be happy?
>> >
>> > I think that a new antenna/filter/amplifier unit would be ok. But the
>> > problem is the installed base of receivers, including all those costly
>> > units used for geodesy or navigation, that have embedded antennas.
>> > Those will be hard to modify.
>> >
>> > 73 - Marco IK1ODO
>> >
>> >
>> >
>> > _______________________________________________
>> > 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.
>> >
>>
>> --
>> Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
>> Developer of Industrial ZMODEM(Tm) for Embedded Applications
>> Omen Technology Inc "The High Reliability Software"
>> 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
>>
>>
>> _______________________________________________
>> 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.
>
>
> _______________________________________________
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> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
CF
Chuck Forsberg WA7KGX N2469R
Fri, Sep 30, 2011 3:20 PM
A wider filter with steep skirts tends to cost more.
Constraints on noise figure, dynamic range, group delay. and flatness
add more cost
and power consumption.
On 09/30/2011 08:11 AM, Bob Bownes wrote:
Exactly. The narrower the filter, the more it will cost. In general.
On Fri, Sep 30, 2011 at 11:10 AM, Tom Holmestholmes@woh.rr.com wrote:
Sticking with the intent to keep this non-political, what good is a filter
if the offending signal is within the necessary passband?
Tom Holmes, N8ZM
Tipp City, OH
EM79
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Chuck Forsberg WA7KGX N2469R
Sent: Friday, September 30, 2011 10:55 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS Interference Question
If LightSquared deploys their high powered LTE network in the satellite
the GPS world will become very interesting indeed. Are LightSquared
to spend $20,000 to upgrade the GPS on my Skylane to a new model which
does not yet exist?
With that many transmitters we may experience areas where RF from multiple
high power transmitters creates hot spots. In some places pieces of metal
with non Ohmic bonds will create mixing products, some of which may fall
directly within GPS bands. These effects have not been simulated.
Who knows who the FCC is listening to - the GPS industry including
of current users, or those who appear to have bought under the table
This could make Solyndra look like small change. Film at 11.
On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
At 15:44 30-09-11, Jason wrote:
To filter out the L2 signal, would an actual GPS receiver have to be
replaced / modified?
Or would a more simple and cheaper alternative be to get a new
antenna (with fancy filtering) to replace my existing roof-top
antenna and expect all my old equipment to be happy?
I think that a new antenna/filter/amplifier unit would be ok. But the
problem is the installed base of receivers, including all those costly
units used for geodesy or navigation, that have embedded antennas.
Those will be hard to modify.
73 - Marco IK1ODO
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.
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
A wider filter with steep skirts tends to cost more.
Constraints on noise figure, dynamic range, group delay. and flatness
add more cost
and power consumption.
On 09/30/2011 08:11 AM, Bob Bownes wrote:
> Exactly. The narrower the filter, the more it will cost. In general.
>
>
>
> On Fri, Sep 30, 2011 at 11:10 AM, Tom Holmes<tholmes@woh.rr.com> wrote:
>> Sticking with the intent to keep this non-political, what good is a filter
>> if the offending signal is within the necessary passband?
>>
>> Tom Holmes, N8ZM
>> Tipp City, OH
>> EM79
>>
>>
>>> -----Original Message-----
>>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
>>> Behalf Of Chuck Forsberg WA7KGX N2469R
>>> Sent: Friday, September 30, 2011 10:55 AM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] GPS Interference Question
>>>
>>> If LightSquared deploys their high powered LTE network in the satellite
>> band
>>> the GPS world will become very interesting indeed. Are LightSquared
>> willing
>>> to spend $20,000 to upgrade the GPS on my Skylane to a new model which
>>> does not yet exist?
>>>
>>> With that many transmitters we may experience areas where RF from multiple
>>> high power transmitters creates hot spots. In some places pieces of metal
>>> with non Ohmic bonds will create mixing products, some of which may fall
>>> directly within GPS bands. These effects have not been simulated.
>>>
>>> Who knows who the FCC is listening to - the GPS industry including
>> millions
>>> of current users, or those who appear to have bought under the table
>> favor.
>>> This could make Solyndra look like small change. Film at 11.
>>>
>>>
>>> On 09/30/2011 07:02 AM, Marco IK1ODO -2 wrote:
>>>> At 15:44 30-09-11, Jason wrote:
>>>>
>>>>> To filter out the L2 signal, would an actual GPS receiver have to be
>>>>> replaced / modified?
>>>>>
>>>>> Or would a more simple and cheaper alternative be to get a new
>>>>> antenna (with fancy filtering) to replace my existing roof-top
>>>>> antenna and expect all my old equipment to be happy?
>>>> I think that a new antenna/filter/amplifier unit would be ok. But the
>>>> problem is the installed base of receivers, including all those costly
>>>> units used for geodesy or navigation, that have embedded antennas.
>>>> Those will be hard to modify.
>>>>
>>>> 73 - Marco IK1ODO
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> 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.
>>>>
>>> --
>>> Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
>>> Developer of Industrial ZMODEM(Tm) for Embedded Applications
>>> Omen Technology Inc "The High Reliability Software"
>>> 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
>>>
>>>
>>> _______________________________________________
>>> 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.
>>
>> _______________________________________________
>> 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.
>>
> _______________________________________________
> 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.
>
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430
