[R-390] Filters

[Bob Camp]

Hi

With the right hardware to target and good design software, the filters are a weekend project code. From scratch the design software stuff likely would run you < $500. 

Bob


On Feb 15, 2013, at 9:22 PM, mlmccauley at att.net wrote:

> 
> Absolutely.
> 
> I've seen those come and go. The concept is great, but the market is very limited, hence the cost.
> 
> A savvy ham with the proper background could homebrew a very nice filter for a relatively cheap price. Soldering the hardware together would be a fairly easy weekend project, assuming you had a surface mount adapter board for the DSP chip. The software would take many weeks to write and even longer to debug.
> 
> 
> On 2/15/2013 8:05 PM, Bob Camp wrote:
>> Hi
>> 
>> Thus the variety of outboard dsp filter boxes that have shown up over the years. Once you get them into production, the cost is high enough that there is a very limited audience.
>> 
>> Bob
>> 
>> On Feb 15, 2013, at 8:50 PM, mlmccauley at att.net wrote:
>> 
>>> A DSP filter would be an ideal replacement for a mechanical.
>>> 
>>> DSP chips that work at 455KHz are readily available for very reasonable $.
>>> 
>>> The problem is the software.  To do a nice, flat topped, steep skirt filter would not be a trivial piece of work.
>>> 
>>> The upside is that one relatively simple circuit could be made to do everything from super-narrow CW to full bandwidth AM SWL.
>>> 
>>> 73,
>>> 
>>> Mike, WB5MYY
>>> 
>>> 
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>