Hi All,
During my monitoring of 500 KHz I have almost always seen a line on SpecLab
at 504.0 KHz. Whilst attempting to improve a shielded loop for 500 KHz I
have been receiving the signal on 504.0 KHz stronger & stronger with
accompanying hetrodyne. After todays changes to my loop the signal has
become so strong that I now hear garbled audio & SpecLab is showing audio
sidebands (see capture attached). I notice that there is a line at the same
frequency on the Bimingham Grabber some of the time. I first thought it was
some product of mixing strong signals in the MF range. I decided to try to
work it out & realised that in fact it is the second harmonic of RTE Radio 1
on 252 KHz. I have studied the uninteligable audio pattern & it does relate
to that signal.
I must admit that I don't know if it due to improvements or some other quirk
of my loop or just the fact that the filtering at RTE Radio 1 is poor.
Although this signal has got stronger with changes to my loop there doesn't
appear to be the same improvement with normal 500 KHz signals.
Perhaps someone can shed some light on this for me.
73
Gary - G4WGT - IO83qp
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