[Fwd: LF: QRN Free Site]
Tue, 09 Mar 1999 16:38:04 -0500
> Hi all,
> Query on QRN versus QRM. LF natural noise levels (QRN) are typically
> well above the front end noise in good receiving gear, and there is not
> much that can be done to improve matters further. The QRN likely
> originates from lightning in the atmosphere. Use of a whip/loop phased
> array producing a carioid pattern can improve S/N a little if the
> atmospheric noise is mainly from directions well away from the signal
> angle of arrival (as verified by Andrew ZL2BBJ and Nat ZL3VN, who
> regularly use phased systems for receiving amateur LF signals)
> On the other hand, man made noise (QRM) can be a real pain in the rear
> end when trying to receive weak LF signals. Keeping as far as is
> practicable away from mains power seems to be the best countermeasure.
> A well decoupled power supply to an active whip sited down the backyard
> can give quite good relief from mains borne QRM at LF.
> Bob ZL2CA
> Andre' Kesteloot wrote:
> > Hello LF Gang,
> > There is nothing that says that my receiver has _got_ to be located
> > next to my transmitter, is there?
> > Over here, we are considering finding a qrn-free site, equipping it
> > properly with a good receiver, taking the whole 2 kHz band and
> > redistributing to all the members, either on a FM repeater, or on the
> > internet.
> > This won't happen probably until the fall, as we are first trying to
> > put a transmitter on the air!
> > 73
> > Andre'
> > *************************************
> > finbar o'connor wrote:
> > WHAT A DIFFERENCE WORKING FROM A QRN FREE SITE MAKES.
> > [...]JOHN /G4GVC HAS MADE A VERY GOOD POINT ABOUT STATIONS
> > PUTTING OUT GOOD SIGNALS BUT BEING UNABLE TO HEAR VERY
> > WELL.