MF Broadcasting stations often change patterns and reduce power at
night due to onset of distance propagation. A receiving high pass
filter that passes 1.8 Mhz and up should do wonders for you. 73, Guy.
On Mon, Apr 5, 2010 at 8:55 AM, Luciano Gasparini Nachif
<luciano_nachif@yahoo.com> wrote:
> I recently installed a Perseus SDR receiver. Last Saturday afternnon, myself
> and PT9IR were playing with it and noticed a very strong noise all around HF.
> I decided to concentrate our efforts on 40 meters as we could rotate the yagi
> in trying to spot the noise source.
> We also installed an AT-130 antenna tuner in between the 2 elem yagi and the
> receiver. If we had it through, the band noise was at least 20dB stronger
> than with the AT inline and we could hear something like music and voices on
> day light.. that was not very clear at night...
> Interesting to mention is that music and voices couldn't completely disapear
> with AT130 inline on day light but almost gone at night.
> We could see 40m station signals with AT-130 inline but nothing without it.
> I found very strong signals on 3720KHz, 7440KHz and or multiples of 1240KHz.
> BTW, the 1240KHz bracasting station is about a mile from my house and I think
> it runs at least 3kW. And I thought I had a lot of QRN at night....
> I believe the right answer shall be a BCB filter but will a BCB and a
> bandpass in series do remove all interference and bring life back into HF for
> me?
>
> 73,
> Luciano PT9KK
>
>
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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