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DVST vs MMST Direct View Storage Tube (DVST) vs Multi-Mode Storage Tube (MMST) by Marvin “Marv” Donnelly 19 Dec 2013

The first 080 unit that “6” [F-106] had was called a DVST. This stood for Direct View storage Tube. Most prominent identifying characteristic was that the scope face – when lit and operating – was a blue or bluish in color. Most were very bright in a full on operation. The scope face was somewhat slanted to cut down the glare for the pilot. The top of the scope was mostly just a big round tube with nothing attached. The forward window had a rigid panel mounted in the “V” formed by the two forward cockpit windows. Only things mounted up in that area were the 169, the hanging optical site and a standby compass. This configuration was used up through the 1970 time frame. Back in 1969 or so the new MMST came into the aircraft. The Multi-Mode Storage Tube as it was called was a pretty big improvement for the pilot. The old DVST had controls for brightness and focus, but the new MMST also included a contrast adjustment and a capability to change the screen from all white (Think bright!) to a reverse screen of all black. Added to this config was the new 149 unit. The 149 was the 8mm video tape recorder to record what was displayed on the 080 screen during the pilot’s attempts to lock-on and make a missile run. The old 149 unit was mounted on the 05 door and had to be changed each time the aircraft flew a mission. To do this the MA-1 person would open the 05 door and remove the old film pack and replace with a fresh one. By putting the new 149 up and attached to the MMST, the changing of a film pack was great improved. The new MMST had the 149 mounted on top of the scope tube and received the display info via a reflective image from the angled scope face plate. The image for the pilot was only slightly dimmed as the image transferred through the scope face lens. The vision splitter panel was modified and cut out to accommodate the new 080 with 149 unit attached. The latter life time of the “6” saw the 080 modified again, this was about the 1982 83 time frame. At this time the “6” was gaining the Vulcan gun mount. The vertical instrument “A” models were all selected for the gun. No round instrument models were given the gun system because of the analog nature of the instrumentation. So – the 080 was modified by changing the 149 unit and making it fit farther forward on the 080, and the HUD – Heads Up Display – had a large combining glass added. The combining glass was installed on top of the 080 with another video splitting mirror inside the scope face. That way the 149 camera got the display video and the gun selection displays could be seen on the combing glass – in front of the pilot. The pilot would use the aim points displayed on that combining glass and the real visual image of what they were following through the forward window. This system actually worked very well! The Vertical instrument “A” models had the 080 with the HUD installed. The other aircraft had the newer 149 unit installed but no HUD. No real problem – just had to make sure the HUD Combining glass was installed as needed. The other two units that were modified for the gun mod aircraft were the 083 (Flight Control Stick) and the 305 unit (RADAR range/IR selector panel). On the armament selector panel the gun was elected by going to Special Weapon. This was because when armed with the gun, the MB-1 Special Weapon rack was removed and the gun pod installed in its place. …Marv 19 Dec 2013

Storage Tubes: DVST vs MMST by Marv Donnelly