John,
> If a LORAN transmitter were destroyed by a terrorist team, a backup could
> be in operation in hours. A damaged GPS system could easily take many
> months or even years to fix.
>
> -John
A LORAN site, with a several hundred meter high mast, a small house full
of transmitter, signal genera
Agreed.
Furthermore, a GPS jammer is VERY hard to locate because the signal levels
are so low.
An effective LORAN jammer could easily be DF'd with a foot sized loop and
tuning capacitor resonating at 100KHz, diode detector, and a set of
headphones. It would be IMPOSSIBLE to hide.
If a LORAN tran
And all the GPS goodness can easily be disabled by a missile and a
near nuclear burst or a portable handheld jammer at the airport.
The portable handheld jammer is a very real threat to GPS due to the
signal levels from the satellite.
Now they are trying to revive a miswired SVN and add it to t
I have been a private pilot for 40+ years, hold an Airline Transport Pilot
rating and am very interested in 'redundancy'. I very much like the
availability of GPS, LORAN, VOR, ADF, and ILS but have never been able to
afford INS. However, I recognize the we (the USA) have limited resources
(nation
LORAN is a good back up, but it has problems and limitations. Navigating
next to a storm can overwhelm the receiver and make it unusable. The LORAN
system doesn't have a build in accuracy degradation system like GPS(RAIM -
receiver autonomous integrity monitoring), and this make LORAN unfit to fl
Bill,
Thanks for the info. I took the can apart, but I couldn't see the
wires. I'll just have to figure it out.
Joe Gray
KA5ZEC
On Sat, Nov 14, 2009 at 6:17 PM, WB6BNQ wrote:
> Joe,
>
> Usually this type of crystal holder is referred to as a bang-bang oven can.
> That
> is the winding is cont
Joe,
Usually this type of crystal holder is referred to as a bang-bang oven can.
That
is the winding is controlled through a on/off thermal switch. On the unlikely
side it could have a simple thermister and a power transistor for a simple
analog
method.
With the octal plug system there should
> I've read and heard from this forum as well as a number of other
> sources that GPS can be easily jammed. What makes GPS so vulnerable?
> How can it be jammed?
The signal is very very very weak. The question is not how can it be jammed,
but rather how can you find the signal at all.
There
Signal strength.
LORAN transmitters put out multi-hundred KW to MegaWatt class pulses. Wiki
has a list. I would think a GPS bird puts out less than 100 Watts CW.
Also, GPS birds are a LOT farther away, especially measured in wavelengths
(much higher path loss)
Those factors combine to make a huge
I have an OCXO in a small, round metal can with an 8-pin base (like an
octal tube). The label on the top has the following information.
Type
T-29-3BB
5070766
1000 KC
115V 75C
Piezo
Carlisle, PA
I've done some Googling, but haven't turned up anything yet. What I am
looking for is the pinout of th
On 11/14/09 3:28 PM, "J. Forster" wrote:
> Somehow, I think they will keep GPS running whatever the cost. There is a
> huge civilian constituency (everybody who cannot or is too lazy to read a
> map) and relies on GPS to guide their Lexus to the nearest Starbucks.
>
> Also, the military needs
I've read and heard from this forum as well as a number of other sources
that GPS can be easily jammed. What makes GPS so vulnerable? How can it be
jammed?
--
David
masondg44 at comcast dot net
From: Francesco Ledda
Subject: Re: [time-nuts] The Demise of LORAN (was Re: Reference
oscillator
There is a difference between falling off a cliff and being pushed.
-John
==
> Indeed the uscg did agree to shut it down.
> They signed off on it.
>
> On Sat, Nov 14, 2009 at 3:40 PM, Christopher Hoover
> wrote:
>
>> David I. Emery wrote:
>>
>>> I have emailed my brother in law who is a
Indeed the uscg did agree to shut it down.
They signed off on it.
On Sat, Nov 14, 2009 at 3:40 PM, Christopher Hoover wrote:
> David I. Emery wrote:
>
>> I have emailed my brother in law who is a rear admiral (I think
>> now called a vice admiral) and currently CFO of the USCG (and as a note
>> r
Somehow, I think they will keep GPS running whatever the cost. There is a
huge civilian constituency (everybody who cannot or is too lazy to read a
map) and relies on GPS to guide their Lexus to the nearest Starbucks.
Also, the military needs it to guide and target munitions. The initial
Afgahnist
I was thinking about the costs side as well. From the 2010 budget info I
have been able to find, "The savings could top $36 million in 2010", with
something like $190M over the following 5 years.
I think that the GPS birds are far more than that to maintain and replace. I
found the following i
John,
I have asked Alaska's representitives to reinstate LORAN funding due to the
large number of private pilots and small fishing boat operators that rely
on LORAN in Alaska. During periods of high aurora activity in the arctic
the interference with GPS makes it unusable and LORAN is the only viab
OK, so who is in a position to MAKE them care? How about those who
understand this is a Homeland Security (among other) issue? Perhaps FOX
news?
Likely LORAN costs about as much a year as a mile of fence along the
Mexican border, probably less.
FWIW,
-John
> You've hit it on th
You've hit it on the nose. NONE of them are interested in anything but
social issues. LORAN will not get any of them re-elected, and that's all
any of 'em care about.
Don
J. Forster
> Does anybody know who in Congress might take the lead in reversing the
> decision? None of the reps in this state
Does anybody know who in Congress might take the lead in reversing the
decision? None of the reps in this state are at all likely to give a damn.
Their interest is apparently only in social issues.
-John
=
> AOPA is pushing congress to repristinate funding for LORAN. General
AOPA is pushing congress to repristinate funding for LORAN. General
aviation is probably the heaviest user on this Nav system. The
aviation user community would love to see Nav systems with integrated
LORAN and GPS capabilty, but the industry has done little in this
area, due to lack of gov
David I. Emery wrote:
I have emailed my brother in law who is a rear admiral (I think
now called a vice admiral) and currently CFO of the USCG (and as a note
re your alma mater a MIT Sloan grad) and rather loudly said so myself.
He most likely was part of the group that made the decision... I i
Thanks for the good comments :)
I am glad to help.
Didier
> -Original Message-
> From: time-nuts-boun...@febo.com
> [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed
> Sent: Friday, November 13, 2009 12:11 PM
> To: Discussion of precise time and frequency measurement
> Subject
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