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
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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
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Problem with Crystal Filters - IMD - RF Cafe Forums
RF Cafe Forums closed its virtual doors in 2012 mainly due to other social media
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August of 2003 and was quite well-attended for many years. By 2010, Facebook and
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Forums activity dropped off precipitously. If the folks at
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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: Problem with Crystal Filters - IMD Posted: Thu
Dec 04, 2008 10:52 pm
Joined: Fri Jan 26,
2007 2:40 am
Anyone have a problem with IMD with crystal
filters? I'm not quite sure what to do about it. I have a 100 MHz BPF
with 15 kHz or so BW. It is pretty much the driver for the IMD in the
radio chain. I could move around the gain distribution but the filter
doesn't have a constant IP3 like most amplifiers. The IMD3 really doesn't
drop at the 2 for every 1 rate.
Is this a common problem with
Posted: Mon Dec 22, 2008 5:34 pm
Mon Jun 27, 2005 2:02 pm
check the impedance match of the crystal to the amplifiers in the chain.
It can be that this behavior is derived by impedance mismatch of the
IMD products compared to a good impedance match of the fundamental signals.
Just my guess...