[TenTec] Orion Noise Reduction Ability

Grant Youngman nq5t at tx.rr.com
Wed Mar 21 18:27:40 EST 2007


> interesting idea
> 
> > A "trick" under uncrowded band conditions that sometimes 
> makes the DSP NB
> > very effective is to force the main rx roofing filters to 6 
> or 15 Khz -

That's been discussed here before.  Not unique at all to the Orion.  When
many people were modifying the 1st IF filters in the Darake R-4C, this
effect reared its ugly head.  Too narrow a filter there would effectively
disable the otherwise very fine NB in the Drake by stretching the noise
pulses beyond what the blanker could handle.  The pulse stretching that
takes place results in noise "clumps" instead of noise "spikes".  And
blankers don't work well with "clumps" :-)

If the NB doesn't seem to be working to your liking, it's always a good idea
to just go to the widest roofing filter manually and see if that improves
things.  Of course, it may cause other problems, but life is full of
tradeoffs :-)

Grant/NQ5T



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