[Elecraft] Setting shift for different filters?

[Don Wilhelm]

David,

OK, I have perhaps ignored the subtle points - in some cases, you will 
have 50 Hz rounding and in other cases, you will have 100 Hz rounding - 
that makes little difference.  50 Hz to a SSB low frequency response 
does not make much difference.


n 2/29/2012 9:16 PM, David F. Reed wrote:
> Don,
>
> thanks for the reply.
>
>  1. when I try using the Lo-Cut, it seems to be confined to 100 Hz
>     increments, so, 150, 250, 350, but no 200, 300, or 100 available;
>     is there a way to set that differently?
>  2. I can accomplish the same thing either way if I understand what is
>     going on, but is there a way to preserve the setting?
>
> Thanks again.
>
> --Dave W5SV
>
>
> On 2/29/12 7:18 PM, Don Wilhelm wrote:
>> Dave,
>>
>> Yes, the default is 1500 Hz.  with a 2.8 kHz filter, that puts the 
>> low end at 200 Hz and the high end at 2900 Hz.
>>
>> AND that is why you should be using the Hi-Cut, Lo-Cut on SSB instead 
>> of Shift and Width.
>>
>> For good intelligibility, you need to have some content in the 300 Hz 
>> range, so set the Lo-Cut to 200, 250, or 300 depending on your 
>> desires and the QRM conditions.  Then change only the Hi-Cut to 
>> reduce the filter width - the width will change, cutting the highs 
>> and the filter center frequency will be automatically changed leaving 
>> the low frequency end unchanged.
>>
>> You will find that you can use a filter as narrow as 1500 Hz and 
>> still maintain SSB intelligibility (for a male voice, a female voice 
>> may need a few more highs).  Using Width and Shift to accomplish the 
>> same thing is possible, but requires a lot more "knob fiddling".
>>
>> 73,
>> Don W3FPR
>>
>> On 2/29/2012 6:38 PM, David F. Reed wrote:
>>> I note that as expected, the center frequency of the bandpass of any
>>> given filter on SSB seems to be 1.5 KHz, whether its the 6 KHz filter,
>>> the 2.7 KHz filter or the 2.1 KHz filter.
>>>
>>> This seems to work out to be passing from 150 Hz to 2.85 KHz, right?
>>> So the 2.1 KHz filter (without using the shift control) passes 450 
>>> Hz to
>>> 2.55 KHz, right?
>>>
>>> I note that if I shift the center of the filter down to 1.35 KHz, the
>>> voices are more intelligible...
>>>
>>> When I switch filters and get back to the 2.1 KHz filter, the shift is
>>> lost; is there a setting I can use to save that shift setting?
>>>
>>> Thanks&  73 de W5SV, Dave
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