Hi! Long-time lurker, first-time poster. I've been into the entire Stargate series since the beginning, and have pretty much soaked up the whole thing like a sponge. After watching the Universe series, and noting some inconsistencies, I've tried to come up with some theories to explain them, which seem to make sense to me.
I don't know if they've been posted before or not. The search function is somewhat less than helpful, so if this has been stated before, please forgive me.
-- Model I
-- Probably made of Naquadah
-- Don't have a DHD or its power source
-- Limited range because of above
-- Can dial galaxy-wide with proper power source and DHD
-- Destiny's Model I can dial earth with enough power, so this isn't an unreasonable assumption.
So, you could basically drop a Model I gate into the Milky way, Pegasus, whatever, and hook
it up to a DHD. It would work just fine within the modern gate system. The differences
between the gates themselves seem to be almost entirely cosmetic. The Model I gates in the
Destiny galaxies don't use a DHD, meaning they aren't linked in a galaxy-wide network, thus
limiting their range. With a DHD and its power source, they should be just as capable as the
Model II and III gates. Stargate technology must have been basically complete by the time
these were constructed, with relatively minor refinements, mostly cosmetic, to come later
on, otherwise the Ancients wouldn't have taken the effort to seed however many galaxies with
Theory: Amelius' Model II specifications are the original, but were inherently flawed in some way.
They were reworked until he arrived at the Model I design. Later on, some unspecified
improvements were made, and the Model II design was completed, similar cosmetically to the
Theory: There may be a number, perhaps several hundred, Model I gates in the Milky Way
Galaxy and possibly even Pegasus, hooked up to DHDs. It's not farfetched, given
the immense number of worlds that haven't been explored. They may in fact have 39 glyphs on
them just like the Milky Way gates, rather than the Destiny-style numerical abstractions.
Theory: The gates constructed by the seedships are a one-off version of the Model I gates.
They're designed as general-purpose gates, rather than for specific galaxies. This way,
they can all use the same symbols in different galaxies. The energy costs of the seed ships
making DHDs may have been prohibitive, or deemed unnecessary for the purposes of the smaller
Theory: The Berzerker Drones were able to blow a huge chunk out of a Model I gate with
relatively small weapons, while a Model II gate can take horrific amounts of blast energy
without even being marked. This doesn't make the Model I gates weaker. It may simply be
that Naquadah is particularly vulnerable to whatever nature Berzerker Drones' weapons
possess. A C-4 explosion and a rock slide didn't leave a mark on a Model I, after all,
which would have more energy than a Berzerker Drone's weapons.
And they wouldn't be very useful, or have lasted as long as they have, if they weren't as durable
as their newer-model counterparts. The gate on Destiny would have exploded in spectacular fashion,
or beenreduced to an inert chunk of metal when they tried to dial Earth if the Model I gates were
Theory: The Model I planetary gates in the Destiny galaxies aren't made of Naquadah, but
another, weaker superconductive element. Maybe, maybe not. That still doesn't explain why a
Berzerker Drone's weapons disabled one gate, but a rock slide and C-4 didn't leave a mark on
another. If Naquadah was that hard to find, there would be a lot fewer Mark II and III
Theory: It doesn't require an Icarus-type planet to dial a 9-chevron address at distances
like Destiny's. A ZPM may be more than adequate for the task. Obviously, nobody on Earth
would take the risk, though. They only have a couple, which they really need where they are at
the moment. Also, the correct 9-chevron address had yet to be found. The Icarus planet
was uniquely suited to testing this out, as it wasn't really good for anything else.
Besides, if anything should go wrong with the ZPM, they'd be kind of screwed, or blown to bits
Theory: The explosion of the Icarus planet had little or nothing to do with the 9-chevron dialing. The
Lucian Alliance was bombarding the heck out of the planet with their suped-up ships. All
they'd have to do is get one lucky shot in and cause an eruption in just the right spot, or
hit the power systems of the base and destabilize them. Then, BOOM. This would also
explain why everyone was hurled through the otherwise stable wormhole at such high speed.