RE: LF: Mains QRM blanker by PA0LQ

["john sexton" <computernetworks@excite.com>]

 Hi Dick,
The noise blanker is of interest here.
I find Spectran an excellent tool for providing the second item, the very narrow adjustable non-ringing audio filter. On its own it removes practically all of the noise.
73, John, G4CNN

--- On Tue 04/30, Dick Rollema

wrote:
>
> To All from PA0SE


> Harry, PA0LQ, active on LF until his landlord forbade his aerial, lives
> in a 12 story apartment block of which corridors are permanently lit by
> fluorescent tubes. These caused such interference that only very strong
> signals could be copied. Harry then constructed a blanker that operates
> on the audio out of the receiver. The blanker can be synchronised to the
> mains frequency and produces blanking pulses of 50 or 100 Hz. Both width
> and position of the pulses can be adjusted for optimum blanking. This
> brought a great improvement in reception.

> Harry combined the blanker  with an active 30 Hz bandwidth
> non-ringing audio filter.


> I described both items in our VERON magazine Electron of June
> 2000.


> If there is interest I am willing to translate the text into English and
> send text and circuit diagram by e-mail to anyone requesting it. Or
> perhaps it could be placed on a website.

> But before taking action I await responses.


> 73, Dick, PA0SE
>

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