LF: Noise blankers, etc

Frank Gentges gentges@itd.nrl.navy.mil
Fri, 18 Jun 1999 21:29:54 +0000 (GMT)


Properly done a wideband LF front end blanker can be synced with the 
power line to gate out a short interval that coincides with a dimmer 
pulse.  There was some good stuff in the Lowdown many years ago that 
looked promising.  I have put a high gain preamp on my scope, watched the 
antenna signal and used line sync.  These pesky pulses were very narrow 
with the wide bandwidth and could have been gated out nicely.  With 
multiple dimmers at various settings the problem gets much harder.

There is some discussion on this on the LWCA web page.

Frank K0BRA

On Fri, 18 Jun 1999, Andre' Kesteloot wrote:

> Dave Sergeant wrote:
> > >From Dave G3YMC
> >
> > Bob ZL2CA says:
> >
> > <It has been noted in ZL that noise blankers do not work so well on
> > <narrowband loop receiving antennas
> >
> > I have never found a noise blanker on any amateur receiver which has the
> > slightest effect on the sort of noise we encounter on 136 or any of the LF
> > bands, and they only really seem to work on ignition type of noise such as
> > you might expect on VHF.  Some recent rigs may perform better, but in
> > reality the noise blanker on most rigs is wasted space and it is no great
> > loss if it works even less well with a narrow band antenna!
> >
> > 73s Dave G3YMC