[Elecraft] Variable bandwidth crystal filter

[Chuck Guenther]

Good review of the flexibility of the K3, Don!

My K3 filter slots are all filled: 2.7, 2.1, 400, 250, and 200.  Using 
the K3 Utility, I can set the 250 Hz filter to kick in at a DSP 
bandwidth of 300 Hz, 250 Hz, or 200 Hz.  But with the upcoming firmware 
upgrades, the flexibility will be enhanced, so I can make the 250 Hz 
filter kick in at, say 240 Hz, if I want to. At least, that's my 
understanding of  what's coming up.  This is a significant enhancement, 
especially at narrow CW bandwidths-- and in my opinion-- much more 
desirable than a new variable bandwidth roofing filter. 
73,
Chuck  NI0C
K2-10 s/n 5853  K3-100 s/n 1061


 
Don Wilhelm wrote:
> Chuck,
>
> True, true *BUT* the roofing filter can suppress signals before they 
> get to the hardware AGC.  If one is happy with only the DSP filtering 
> alone, then do not purchase any roofing filters at all, just go with 
> the stock 2.7 kHz roofing filter.  Different strokes for different 
> folks, some need the additional filtering, others do not - and others 
> will purchase a full set of filters just to have them available - the 
> choice depends on your operating habits and expectations as well as 
> your ham radio budget.  The casual operators will have great success 
> with only the 2.7 kHz filter, but a contester will want a full 
> complement of roofing filters to fight those 'tough times'.
>
> 73,
> Don W3FPR
>
> Chuck Guenther wrote:
>> I simply meant that if folks were looking for a more or less 
>> continuously variable selectivity in the K3, then the 10 Hz increment 
>> DSP filters would provide that, for all practical purposes.
>> 73,
>> Chuck  NI0C
>>
>>
>> Ed K1EP wrote:
>>  
>>> At 8/5/2009 07:51 PM, Chuck Guenther wrote:
>>>
>>>    
>>>>  With the upoming 10 Hz resolution DSP upgrade (Firmware 3.23 being
>>>> talked about), I certainly wouldn't see much need for a variable BW
>>>> roofing filter.
>>>>       
>>> Can you explain that relationship?
>>>
>>>
>>>    
>>>> 73,
>>>> Chuck  NI0C
>>>> K2, K3
>>>>       
>>>     
>>
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