Copyright: 1996 - 2024
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling
2 MB. Its primary purpose was to provide me with ready access to commonly needed
formulas and reference material while performing my work as an RF system and circuit
design engineer. The World Wide Web (Internet) was largely an unknown entity at
the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps
while tying up your telephone line, and a nice lady's voice announced "You've Got
Mail" when a new message arrived...
All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the RF Cafe website are hereby acknowledged.
My Hobby Website:
data filter - RF Cafe Forums
RF Cafe Forums closed its virtual doors in 2012 mainly due to other social media
platforms dominating public commenting venues. RF Cafe Forums began sometime around
August of 2003 and was quite well-attended for many years. By 2010, Facebook and
Twitter were overwhelmingly dominating online personal interaction, and RF Cafe
Forums activity dropped off precipitously. If the folks at
phpBB would release a version with integrated
sign-in from the major social media platforms, I would resurrect the RF Cafe Forums,
but until then it is probably not worth the effort. Regardless, there are still
lots of great posts in the archive that ware worth looking at.
Below are the old forum threads, including responses to the original posts.
|-- Amateur Radio
Gripes & Humor
-- CAE, CAD, &
Test & Measurement
Post subject: data filter
Unread postPosted: Mon Mar 28,
2005 3:09 pm
I'm looking for an active filter for my 10kbps
TTL data line.
Any ideas what the lowest possible Fc can be for
the filter? Any suggestions for MFG's of such filters?
Post subject: Data Filter
Unread postPosted: Tue Mar 29, 2005 1:47 pm
to your question probably comes from several other questions:
Why do you want a filter at all?
2. Where is the data going?
How much stop-band attenuation do you really need?
4. How much are
you willing to pay for the very narrowest possible bandwidth?
The (unattainable!) limit would be 5 kHz. Any reasonably narrow
filter will either require a phase equalizer to remove inter-symbol
interference, or be many stages of (approximately) linear phase filtering,
such as Bessel filters.
Most filters are either custom-made (read
$$$) or do-it-yourself with building blocks from an IC company such
as Linear Technology (www.linear.com). LTC offers free design software
for their chips.