[Elecraft] K3 Narrowing the filters on SSB

[David Ferrington, M0XDF]

don't you think that would get complicated and of course you'd have to do
the opposite for USB (wouldn't you?). The way it is now, the rig is not
second guessing what your trying to do and your not having to figure out
what its doing.

just my 2c worth


On 03/03/2008 05:40, "Tony Fegan VE3QF" <jafegan at rogers.com> sent:

> Don,
> 
>     At present the filter centre frequency is unchanged as the filter
> Width is reduced. If the centre frequency on SSB could be reduced by
> half the change in bandwidth then the LO-Cut frequency would remain the
> same. This is the same as how the Hi-Cut works. If we now add another
> variable so that when the bandwidth goes below about 2.2KHz, we slightly
> reduce the reduction in centre frequency, then this could start to raise
> the Lo-Cut frequency up to about 500Hz by the time we reach a bandwidth
> of 1.0KHz.
>     This would allow the Width control on SSB to be used just like on
> CW. Just one control right down to the narrowest bandwidth.
>     I tried your suggestion of moving the VFO at the narrower bandwidths
> but did not find any improvement over raising the Lo-Cut frequency. I
> was careful to tune in to signals close to their correct frequency and
> not where they sounded best. I found that a signal in the clear could be
> copied down to very narrow bandwidths but with QRM it was easier to copy
> on a slightly wider bandwidth. Of course it all depends on which side
> the QRM is.
>     Maybe this topic should be renamed to "Digging in the dirt". I like
> looking for those very weak signals. At least my ears work fairly well,
> even if the associated processor is a bit suspect.
> 
> 73
>     Tony Fegan VE3QF
> 
> 
> Don Wilhelm wrote:
>> Tony,
>> 
>> If you loose substantial intelligibility when moving the Hi-cut to
>> narrow the SSB width, try moving the VFO just a bit.  With a properly
>> tuned SSB signal and Lo-Cut set to 0.25, I can dial Hi-cut down to
>> about 1.05 and still understand what is being said.  If the signal is
>> slightly mistuned, then intelligibility suffers when Hi-Cut is reduced
>> below 1.85.
>> 
>> The problem with making a 'center tracking' SSB width control is that
>> it would do the same thing as Hi-Cut does now - I don't know how that
>> would solve anything.
-- 
A person usually has two reasons for doing something: a good reason and the
real reason. -Thomas Carlyle, historian and essayist (1795-1881)