In article , Mike Coslo writes:
Kim wrote:
Hmmmm, Jim/N2EY made that observation also. Then, I see the comment that
spark was a transmission method--not a mode. I think that's splitting
hairs, isn't it? I'm asking--I wasn't around for spark
They called it "Mode B". And there were also arc transmitters - not the same
thing.
and
Whoooohooooo, I know a few of those "forever" gang down here--and they are
as passionate about AM as any ardent CW fan! Dems would be fightin' words
in this neck 'o the woods. At any rate, so you're bringing up the scenario
that someone outside the FCC would bring up a petition to ban a mode.
Hmmmmmm, hadn't thought of that--but why? Why would anyone want to have a
mode banned? I mean, seriously, what would be gained?
Spark is very, very wideband. This was probably a good thing in th
early days of radio, since the transmitter and reciever didn't have to
be tuned too closely to each other.
Some receivers were not even tuned at all.
A modern day example might be a failing transformer on a power line. If
something is arcing inside it or to a connection, it can put out a lot
of rf noise that extends over a lot of bandwidth. It would mess with
almost any rf device in the house.
That's why spark was banned.
That's one reason.
Another was that almost nobody was using it after about 1924-5, but there was
concern about folks looking at "old" books and thinking they could still use
it.
Consider how fast the change came. When hams got back on the air after WW1,
spark was undisputed king. Five years later, it was a memory. The difference
between a "state of the art" 1919 ham station and a similar one in 1939 is
simply amazing. Almost nothing from the former would still be in the latter.
As for AM, I have no problem with it. It does use more bandwidth
though, and that is why some hams and others don't like it. But to me
it's a cool "retro" mode. Not very efficient, but who says it has to be?
Depends how you define efficiency. AM operations tend to be roundtables where
many hams gather on one freq. So the number of "Hz used per ham on the air" can
be pretty low.
73 de Jim, N2EY