Re: K3: killing RX key clicks
Posted by
gm3sek on
Dec 02, 2009; 11:42pm
URL: http://elecraft.85.s1.nabble.com/K3-killing-RX-key-clicks-tp4093607p4103162.html
Paul Christensen wrote:
>> The 'RC rise/decay' wave shape that was in the handbooks for many years
>> is actually a *bad* shape because it has a very sharp corner on key-up.
>
>Ian, *bad* may be a bit too harsh. The League's optimized envelope was
>described during a time when only simple R/C values were used to
>develop a keyed envelope. I'm not sure how one would have produced an
>economical Blackman-Harris or raised cosine function until say...the
>early to mid '90s. How would you have done it? Probably the only
>solution at the time was to set leading and trailing edges produced by
>the R/C network so soft that they're painful to copy.
>
My criticism was that because R/C shaping was judged to be the only
available technology, it was wrongly promoted as being the optimum that
designers should aim for. Given better information, I believe designers
could have produced analog circuits to approximate the true optimum
shape... but that didn't happen.
--
73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek______________________________________________________________
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