How many SDF-#'s are there?


From my understanding, there are three SDFs:

  * The SDF-1 which was the major focus of the first season.
  * The SDF-3 which is the flagship of the Robotech Expeditionary Force (REF), where Rick Hunter is.
  * The SDF-2 I wasn't too sure about, as at first I thought it was a separate ship built, but it was apparently destroyed with the SDF-1 in the final episode of the first season. (Not entirely sure if it's a separate ship or the repaired SDF-1.)

However, in Episode 78 ("Ghost Town"), the communications from the REF were
coming from the SDF-4, so I'm wondering: How many SDF-#'s are there, and are
they all the same as the SDF-1 (minus the aircraft carriers which were just a
patch job)?




The [Robotech Wikia](http://robotech.wikia.com/wiki/SDF) has a list for SDF-1,
SDF-2, SDF-3, SDF-4 and SDF-7. It includes a listing for SDF-M, but I don't
think that was in the TV series (it's mentioned in the Robotech comics).
Wikipedia also has a list of [Robotech
vehicles](http://en.wikipedia.org/wiki/List_of_Robotech_vehicles) that has a
lot of detailed information of 1-4.

  * **SDF-1** : Robotech TV series
  * **SDF-2 Megalord** : Robotech TV series (starting from episode 26)
  * **SDF-3 Pioneer** : First appeared in ["Crystal Dreams" promo](http://images1.wikia.nocookie.net/__cb20120820223908/robotech/images/f/f6/Incomplete_SDF3.jpg) and in the Robotech II: The Sentinels series
  * **SDF-4 Izumo/Liberator** : Last episode of the original series
  * **SDF-7** : Robotech II: The Sentinels novels 
  * **SDF-M** : Invid War: Aftermath comics

The SDF-7 was a Horizon Class T ship, so it's not like SDF-1.




The [Robotech Wikia](http://robotech.wikia.com/wiki/SDF) has a list for SDF-1,
SDF-2, SDF-3, SDF-4 and SDF-7. It includes a listing for SDF-M, but I don't
think that was in the TV series (it's mentioned in the Robotech comics).
Wikipedia also has a list of [Robotech
vehicles](http://en.wikipedia.org/wiki/List_of_Robotech_vehicles) that has a
lot of detailed information of 1-4.

  * **SDF-1** : Robotech TV series
  * **SDF-2 Megalord** : Robotech TV series (starting from episode 26)
  * **SDF-3 Pioneer** : First appeared in ["Crystal Dreams" promo](http://images1.wikia.nocookie.net/__cb20120820223908/robotech/images/f/f6/Incomplete_SDF3.jpg) and in the Robotech II: The Sentinels series
  * **SDF-4 Izumo/Liberator** : Last episode of the original series
  * **SDF-7** : Robotech II: The Sentinels novels 
  * **SDF-M** : Invid War: Aftermath comics

The SDF-7 was a Horizon Class T ship, so it's not like SDF-1.

