[Boatanchors] LightSquared

[D C _Mac_ Macdonald]

More on LORAN: 
 
Unless you had a LORAN-A transmitter VERY close to 
your location, it is unlikely you could tell which 
station was where.  LORAN-A stations had a "MASTER" 
and "SLAVE" relationship.  I no longer remember from 
my days as a student navigator if it was a one-to-one 
relationship or if there could be more than one slave 
per master.  The chains of stations were spread along 
the coasts in many parts of the world.
 
Charts were drawn with parabolic curves of TDs (time 
delays or differences, IIRC) for a given master and 
slave.  A slave had its pulse delayed from that of its 
master and the lines on the charts located all the 
points where a specific time delay would exist.  These 
lines were VERY accurate for the technology of that 
time in history.  When the marine or aeronautical 
operator logged a TD from two (or more) different 
slave/master pairs, the point where those TDs crossed 
provided a definite and accurate "fix." 
 
It was important that the navigator/operator ensured 
that stations providing "direct wave" reception were 
chosen.  Signals arriving via "sky wave" would have 
delays that degraded accuracy.  Accuracy, therefore, 
was higher the closer you were to the transmitter 
chains.  Of course if you are in the middle of the 
ocean, knowing your location within a few miles is 
probably adequate.  Close to shore, accuracy could 
get down to a few yards, I believe.  Fishermen loved 
LORAN for its repeatability in finding "hot" spots! 
 
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk at hotmail.com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
* * * * * * * * * * * 
 
 
 
> From: 1oldlens1 at ix.netcom.com
> To: jfor at quikus.com; w3nu at roadrunner.com
> Date: Thu, 11 Oct 2012 09:20:10 -0700
> CC: boatanchors at mailman.qth.net; drewrailleur807 at yahoo.com
> Subject: Re: [Boatanchors] LightSquared
> 
> 
> ----- Original Message ----- 
> From: "J. Forster" <jfor at quikus.com>
> To: "Charles Ring" <w3nu at roadrunner.com>
> Cc: <boatanchors at mailman.qth.net>; "Drew P." 
> <drewrailleur807 at yahoo.com>
> Sent: Thursday, October 11, 2012 7:31 AM
> Subject: Re: [Boatanchors] LightSquared
> 
> 
> > There is not much to hear on either LORAN-A or LORAN-C.
> >
> > At any fixed location, the signals will not vary in time.
> >
> > LORAN-A is just a short RF pulse, followed a fixed time 
> > later by another
> > identical pulse; repeat ad infinitum.
> >
> > -John
> 
> I used to hear Loran-A all the time, it had what music 
> people call a phasing or flanging effect so that the pitch 
> of the pulses ran up and down cyclically. It was a great 
> signal for testing noise limiters. I could just barely hear 
> a Loran-C station on my BC-779 but I did not attempt to make 
> any sort of LW antenna. I have no idea where that station 
> was but the Loran-A station must have been in San Pedro 
> because it was consistently very strong both day and night.
> 
> 
> --
> Richard Knoppow
> Los Angeles
> WB6KBL
> dickburk at ix.netcom.com