[Lf] Re: Further results on monitoring 136.745kHz

[Andre' Kesteloot]

Alan,
thanks for your efforts.
I need to think on how to achieve that shift with the minimal amount of
problems.  The transmitter on 136.745 is about 70 minutes from my QTH, so I do
not want to have to go and come back too often the same day :-)
I shall try and think of a simple mod, then try it at home, and then send it to
the transmitter site.
Around what time in the morning did you see those traces of interest?
73
Andre'
***************************
Alan Melia wrote:

> Hi Andre' , hope you enjoyed the festivities.
>
> On the morning Sunday of 2nd Jan 2000, the locals seem to have had a surfeit
> of TV or have gone to church, because I have the lowest local noise level
> for some time. I have continued to experiment with long integration time
> monitoring using Spectrogram. This morning I have a fairly clean plot of the
> 'daytime' Loran-C lines in the area between 136.7 and 136.8kHz. My surmise
> is that because I am within about 500 kms of both the German and French
> Loran-C sites I should get very little diurnal change in signal strength
> (BIG assumption!) as the signal should be received by ground wave. I can in
> fact read off the lines and they check against the frequencies measured on
> my overnight plot that I advised you of earlier.....except that there is
> distinctly only one line received in the vicinity of 136.745kHz !! My
> over-night plot showed two lines with one seeming to fade away at dawn. So
> far so good but I am not really convinced yet!
>
> The permanent lines around your beacon frequency showing here read off as
> follows:-   (Hz only)  734, 739, 741 very weak, 745, 749, 751
> I guess that they are accurate to about 0.5Hz I have a calibration line on
> the plot from a synthasised generator which is calibrated against an off-air
> standard to about 0.2Hz, the rest depends on the linearity of the plot from
> Spectrogram. At least the lines seem to appear repeatably on my system.
>
> In order to get a definite identification, I am suggesting that a frequency
> shift of between 2 and 4 Hz to the hf, for a period of at least 100 seconds.
> This would move your beacon into an area between the lines that is
> relatively clear, as far as I can ascertain. (+3Hz for 2 minutes would
> probably be ideal with my present parameters)
>
> I have copied this to Dave Pick G3YXM for information
>
> 73 de Alan G3NYK (ever the optimist!) in JO02PB
> Alan.Melia at btinternet.com