What is the difference between V-750V 11D and V-750VM/VMK 11DM/DMK missiles,
Manual from page 27... and between SA-75M/MK Dvina “doghouse” (SA-2F) and say 2, SA-75M Dvina “three van” (SA-2B) with V-750V 11D (Guideline mod.1) (partuculary in tracking and missile guding...).
... Maybe SA-2F has some upgrades we didn't know, except the new missile.
At the bottom of this page, you can find several hundred pages technical bulletins, describing these upgrades.http://historykpvo.narod2.ru/
(after ASURK-1, look for 36..51, CA-75MK)
The first SA-75 Dvina "five van" (SA-2A) was not upgradable, and had lower performance than the "three van" version.
This type was removed from service in 1975.
The SA-75M Dvina "three van" (SA-2B) was the system fielded from 1960, that were constantly upgraded during its lifetime.
1965, it received the H<1 mode (not simulated)
1969, missile beacon transmit power increased from 20W to 80W (against missile channel jamming)
PA-OO cabin the "Doghouse" for target optical tracking (not simulated)
RAB po K3, ADA mode, Ground mode, APP-75M
This Mid Life Upgrade was huge, and took half year of work for each battery.
You can read about it here in detail:http://narod.ru/disk/22604347000/%D0%98%...%201..djvu.html
This modification was noticed by the US, and this version received the misleading SA-2F code.
1973, IFF (not simulated)