[Lowfer] Spectrum Lab as LORAN receiver

[Stewart Nelson]

Hi John and all,

Many thanks for the post.  I had tried this a while ago with
"out of the box" settings, except for GRI, and was disappointed.
But with a little tweaking, you can get awesome results!
I believe that anyone should be able to see and measure all
stations within 1000 miles with this tool.  I would think that
in a quiet location, at least some of the time, one could
see across the country or across the pond, perhaps even further.

A local capture: http://www.scgroup.com/ham/loran3.gif .

From left to right, you can see Fallon (master), George,
Middletown, and Searchlight.  The chain info is at
http://www.megapulse.com/table.html and there is a map at
http://www.megapulse.com/pix/chain/9940.gif .

The Fallon signal is distorted because I aimed the
loop to null it out, and it was nearly quadrature with
the LO when the capture was taken.  Middletown appears
inverted, compared with the other secondaries.  That's
because propagation delays to this receiver are such
that the carrier arrives in approximately opposite phase.

My settings:
1. Time domain scope connected to output L5.
2. Using LORAN preset, but tSync set to *twice* the GRI
   (0.1988 in my case).
3. Turn on the mixer (DSB) and oscillator for left channel.
   Set oscillator frequency to exact carrier.  You need to
   be within 0.05 Hz for decent results.
4. Turn on lowpass filter with ~1500 Hz cutoff.
5. Set suitable gain on filter output amplifier.

Please post your LORAN DX achievements here :)

73,

Stewart KK7KA


----- Original Message ----- 
From: "John Andrews" <w1tag@charter.net>
To: <lowfer@mailman.qth.net>
Sent: Thursday, January 01, 2004 10:47 AM
Subject: Re: [Lowfer] Question...


> Stewart, et al:
> 
> If you want to play with a "free" Loran-C monitor, try the "Loran Monitor"
> in Spectrum Lab's Time Domain Scope option.
> 
> John Andrews