I've just finished watching 48 Hours, the one where they negotiate with the Russians to borrow their DHD so they can get Teal'c out of the Stargate's memory, and I'm confused about something. Chances are that I've just missed something in an earlier episode, but hopefully one of your guys will know.
Earth has two Stargates.
The "alpha" gate was discovered buried under Giza Plateau, and became the gate used by the SGC for the first few years. No DHD was discovered with it, instead the Germans found it and was recovered by the Russians at the end of WW2.
The "beta" gate was discovered buried in Antartica along with its DHD. Both were placed in storage at Area 51, and while there were used by the rogue NID operation until its discovery in Touchstone. After this the beta gate is transferred to the SGC (presumably with its DHD).
During the events in Nemesis/Small Victories the alpha gate is presumed destroyed in the Beliskner crash, and replaced at the SGC by the beta gate.
In fact, the alpha gate is recovered from the bottom of the ocean by the Russians, connected to the DHD they recovered from the Germans, and used (briefly) in their own Stargate program.
In 48 Hours, the Americans borrow the Russian's DHD to rescue Teal'c, and in the process blow it up.
What I don't understand is why this is necessary; from above, the SGC has the DHD from the beta gate and the Russians had the DHD from the alpha gate. So why didn't the SGC just plug in their DHD? In fact, why haven't the SGC done this before and replaced their jury-rigged dialing computer?
Almost certainly, I've missed the loss or destruction of the beta-gate DHD (I can't believe there would be a plot-hole that big in the series), but where did it happen?