IMHO, the best approach is to terminate the mod xfmr (or any audio xfmr)
for best transient (square ware) response of the modulated envelope, not
just an arbitrary upper frequency.
Adjust for best stability, least overshoot and ringing on leading edges,
and the least tilt. Check it at mid freq's,
The phone company is responsible for that illogical 3 kHz upper limit. The
consonant sounds are missing unless you go above 4.4 kHz( 5 kHz is a good
compromise).
Joe W4AAB
- Original Message -
From: Gary Blau [EMAIL PROTECTED]
To: Discussion of AM Radio amradio@mailman.qth.net
Sent:
Gary
I have read several of your writings that refers to tilt. What is it, or
where can I go to learn more about it?
Byron W3WKR
I have always admired what Don has done with his modulation system. That 3400
hertz brick wall filter is a rarity unless one uses high technology active
circuitry such as active op-amps, switched capacitor filters, dsp, etc. I
believe Don has a passive module that does a great job. I wonder
What about bandwidth? +/- 5kc would be a 10 kc band width. I thought we
were supposed to limit our band width to 6kc. Please correct me if I am
wrong.
73, Ed Richards K6UUZ
On Fri, 24 Sep 2004 23:37:25 -0500 Crawfish [EMAIL PROTECTED]
writes:
The phone company is responsible for that illogical
If you listen around on AM much, there are very few 6 kHz signals, just like
SSB. I hear lots of the SSB boys wider than 6 KHz.I don't believe that is
according to the rules, but then, unless someone is being a real pain in the
neck, the FCC isn't going to start measuring bandwidth.They have more
Ed,
You make a good point. I do however need to bring up that bandwidth needs
to be specified with a certain roll off in DB. For example a mechanical filter
in a receiver is often specified at -6, and -60 db and with a certain shape
factor.
A clean AM ham rig may be 30 Khz wide at the
Hi Jim;
For the 55 years I have been in electronics, bandwidth has always been
defined as the half voltage points (-6dB). We all know that band passes
don't have vertical sides. Therefore it will be narrower above the -6 dB
points and wider below. Thanks for your input.
73, Ed Richards K6UUZ
How you interpret the rules or who you believe on the air is always
confusing, so here's the FCC's present rules on emission and bandwidth:
http://frwebgate.access.gpo.gov/cgi-bin/get-cfr.cgi?TITLE=47PART=2SECTI
ON=202YEAR=2001TYPE=TEXT
Here's FCC's General Rules and Regulations:
OPPS I sent this via the wrong EMAIL again. I'm sorry
Here it is via the proper email
**
This is the Official notice for the 2nd annual - WA5BXO BBQ to be held on
Halloween day, Sunday Oct 31, 2004
See The link below
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