[HBR] HBR's in 2014?

[Bill Cromwell]

Hi Brian,

I have some radios with some narrow filters. And some narrower filters. 
And some narrower, yet. Somebody mentioned the DSP filtering and that 
does a nice job of slicing things down pretty tight without the ringing. 
It does present other problems but usually also offers a way around 
them. Like - what's going on the rest of the band. Look at the waterfall 
display <grin>.

I always open up my 'conventional' filtering when I'm searching and 
pouncing and if needed I start choking the knothole down after I find a 
"target". If I don't need it I just leave the wide SSB filter in for CW 
- or even the AM filter. And the AM filter for SSB. I have separates so 
whatever I use on receive does NOT apply on transmit.

If we listen to that howling and ringing it's like holding your head in 
a tub of water and is very tiring. Aside from the DSP filtering as used 
in SDR and other digital stuff, there are some slick tricks that can 
enhance the abilities of the grey filter between your ears without 
hurting your ears. Feed your audio signal into a pair of wide audio 
filters - one high pass and the other low pass with the rolloff at the 
same frequency. Hook the two channels to stereo earphones and you find 
signals at slightly different frequencies are "at" various 'locations' 
around you to help you sort them.

Another thing I have done on CW is use two BFOs at different frequencies 
so that their beat note against each other is outside the audio 
passband. You can maneuver the desired signal into a sweet, harmonious 
spot while moving the qrm into a gadawful cacaphony...easily sorted by 
the grey matter. I haven't tried using both tricks in one pass. For a 
simple look at this, tune the same signals with two different receivers 
to just slightly different frequencies. ease one or both up or down just 
a little and see what happens to the incoming signals.

73,

Bill  KU8H



On 12/08/2014 02:23 PM, Brian Burns wrote:
> Hello All,
> ---snip---
>
> Doing a bit of SWLing with my HQ-150, the bands don't seem as crowded as I
> remember their being, back in the day. Perhaps my obsession with selectivity
> is misplaced?
>
>   
>
> If I remember him rightly, Carl KM1H, said that selectivity gotten with
> tuned circuits, I.F. strips, not crystal filters or Q multipliers, leaves
> the signal sounding better. Certainly the high Q devices like crystals tend
> to "ring" a lot at narrow selectivity settings. Any opinions?
>
>   
>
> Cheers,
>
>   
>
> Brian
>
>