Hello Peter...
I don't have a set of FCC rules here at home, but my recollection is that
(in fairly typical FCC fashion) there is no explicit "dB" IMD requirement,
at least for amps. Think rules say "use good engineering practice" -
whatever that may mean at a given time! (Can someone confirm or correct
that?)
While many exciter/transceivers seem to be no better than -25 dBc & some
may be as bad as -20 dBc, I think FCC would frown on a maximum-legal-power
amplifier type acceptance application showing that level. Certainly hope
so! Nowdays, to the best of my knowledge, they rarely if ever request a
sample amp to do their own lab tests -- too buried in cable, cellular, and
similar issues I guess.)
73, Dick
-----Original Message-----
From: Peter Chadwick [SMTP:Peter_Chadwick@mitel.com]
Sent: Wednesday, September 02, 1998 2:09 AM
To: 'amps'
Subject: [AMPS] high IMD drivers
KM1H says
>Feed foreward, aka distriputed amps, have been around for many years in
>SS and tube form.
Nope, Carl. Feed forward could be applied to a distributed amplifier, but
they are totally different beasts.
Another approach is either Polar loop or Cartesian loop, both of which are
a
lot easier for narrow band signals. Feed forward is more of a wide band
technique.
Dick, where does the FCC regulate intermods in the amateur service? I know
it regulates harmonics. I also know that Part 97.307(d) should be updated
if
the FCC regs are to be in line with the ITU Radio Regulations after 2003,
but the FCC are showing no signs of doing this.
73
Peter G3RZP
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|