[TenTec] Orion AM ALC

[Rob Atkinson]

Hi Jerry,

Thanks for your reply.  I'm afraid I remain unconvinced.  A 56 year
old QST article (there have been some technological developments since
then) and your recollection are not an adequate substitute for a cite
of a current FCC Part 97 portion explicitly prohibiting A3 positive
modulation over 100%.   I understand that domestic medium wave AM
broadcasters are limited to 125% positive now.  Such a limit for hams
would be good practice however, once again, if an operator is linear,
not clipping his carrier, i.e. meeting current spectral purity
requirements and is within the American 1.5 KW PEP limit, there is, as
far as I know, no reason why he cannot go asymmetric even to 150%
positive.  As another fellow mentioned, the human voice (especially
the male voice) results in a natural asymmetry.

In your paraphrasing of the FCC's comments, (I imagine they employed a
more technically rigorous term than "splatter") from memory, you
mention that this ham had a problem with "splatter."  That tells me he
probably clipped his carrier and indeed that would violate an FCC
spectral purity rule then and now; but I invite you to examine Part 97
for specifics regarding a positive modulation limit.  I would like to
know about it because I regularly hit about 120% positive while
getting up to around 95% negative, because I have an asymmetric voice
that I limit accordingly.    If you can find anything I will be
grateful and gladly comply with it however it would certainly be news
to me.

73

Rob
K5UJ



http://www.arrl.org/files/file/Technology/pdf/5610027.pdf And I recall
its author loosing his license by insisting ultra modulation met the FCC
rules, probably
57 or '58. My general was dated October 56 the month of that article
(QST Oct 56 pages 27-29).

As I recall, he claimed it couldn't splatter, the FCC said it splatters
so quit using it and he didn't.

73, Jerry, K0CQ