On 11/30/2021 at 10:25 PM, RWW said:

I asked our question to a fellow collector who is much better at researching things than I am.  He found the answer in the TO on strobe lights.  The answer is a very simple supply issue.  -5209 gets you the strobe, battery, and case.  -1778 only gets you the strobe.  Now we know!

 

Nicely done ! any idea when that T.O. was published ? I've often wondered if a MXU-507 filter would be proper in a late war SRU-20 ?

The stock number for the IR filter was assigned 02/19/1968.  I am not sure the -20 was around much after 1970 or 71. It is listed in the Feb 1968 TO but gone by April 1971. 

 

The TO in post 49 dated 15 June 1987.  Below is from the 1 May 1998 TO.  It has the BA batteries listed.

 

 

Awesome ! thank You !

The strobe in the lower right has the early,  no sticker.. I never looked at the back to see if it was USAF vs US, most likely it was USAF?

I hope someone here saw the early light in the lot on Ebay....wish I paid more attention to the nuances of these little lights... 

 Not sure about the light, the strobe-case however is the early-type without the two lanyard-grommets (seen in the other three cases) 

So here's a an ACR orange-top battery with an 86 date, I've always assumed the orange-tops were strictly 60's era. Enjoy !

40 minutes ago, Jpage said:

So here's a an ACR orange-top battery with an 86 date, I've always assumed the orange-tops were strictly 60's era. Enjoy !

They kept those caps on the civilian batteries for a long time I believe.  The DoD ones discontinued them in the mid 70s I think. 

Here is my current mix of Vietnam era SDU-5/E strobe lights.  1967, 1968 and 1970 contracts, Sorry for the glare on the 67 contract.  I'll have to see if I can find a 69 contract to have sequential years.

Better shot of the 67 contract with less glare.

I have a bag of SDU-5/Es that I got a while back with no batteries. Scored a box of batteries on ebay to equip them all. I took the dead batteries and busted off the cap so you can use 2 cr-123s to power the strobe. Works real well and I'll always be able to use them now. Some people make custom machined brass battery caps but they are typically more expensive than buying a battery

Interesting topic!  I do have a couple or so questions and some additional information.

---What year did the USAF start painting the upper part of the SDU-5/E black?

---What were the FG-1 and FG-1A flashguards?

 

The National Museum of the USAF had on display in their Vietnam section a Japan made light marker/strobe light with a white plastic body and a split clear/red lens at the top.  One of the bottom corners had a removable block which could be turned around and be plugged into an outlet for recharging.

I had one of these in the past, but with an orange plastic body that came with a USAF CWU-27/P flight suit and a lighted USAF kneeboard group.  The one

on display at the NMUSAF is either displayed with their 1966 era SRU-21/P survival vest and contents display or with a B-52 HGU-2A/P helmet and ejection

seat armrest trigger display.

 

As best as I can come up with, the USAF started painting SDU-5/E's in mid 1967. It probably took a year or so until everything was painted.

 

There is no reference to an FG-1 or FG-1A in any manuals or literature that I have seen. There does seem to be some variations in the shape of FG-1B's though. I have seen them where the end with the slots are the same size and shape as the rest of the body and some that have a very defined shape to that 3/4" or so. Below are examples of what I am trying to describe.

Both flashguards have similar markings

 

I think the light you are referring to is a SANYO NL-221 Rechargeable Flashlight.  It is compact, rechargeable, and has dual red/ clear lens focused bulbs and an integral 115-V recharging plug.  Operates ~80 minutes per full charge that can be renewed hundreds of times.  Two 2.2-volt clear bulbs provide you with either red or clear light at the flick of a switch.  Measures 4.5 x 1.75 x 0.75 inches.  At the end of the case is a rubber socket for changing out the bulbs that pushes into the base. These lights were very popular with B-52 crew members stationed on Guam. The photos below are courtesy of a friend who I really wish would join the Forum. He would be a great asset to all of us!

 

That same friend sent me these pictures of one of the earliest strobes issued. This is a 1964 dated USAF marked example.

Thank-you very much for the replies.  Interesting FG 1B variations.  What year was the black plastic below the clear lens introduced on the SDU-5/E?  The ones I had seemed to be around the 1975-1977 timeframe.

 

On 12/1/2023 at 11:08 PM, RWW said:

That same friend sent me these pictures of one of the earliest strobes issued. This is a 1964 dated USAF marked example.

The "Matrix" marked SDUs ( with the Naval Aviator wings) must pre-date 1964 then ?

Both strobes have the same FSN which was assigned 1 January 1963. The SDU-5/E drawings are USAF drawings, so I would say they are about the same time frame, maybe the Matrix USN lights are a little later since the USAF did the drawings, I can't see the Navy getting them before the Air Force did. 

Looking for a blue filter for the SDU-5/E.

Walking through my downtown business district, this caught my eye in a thrift shop window. Couldn't turn that deal down.

 

I finally found a Matrix Navy marked strobe with a Matrix battery!

That's a rare bird. Awesome price too !

Yes, they are!  This is the 1st one I have ever seen for sale in all my years of collecting.

19 hours ago, RWW said:

Yes, they are!  This is the 1st one I have ever seen for sale in all my years of collecting.

Seen three in the last 25 years, bought two.....

I have managed to collect all the filters that we made for the SDU-5 that were available thru China Lake during VN. The green one I just got from a VN era SEAL I know and to be honest I never thought I would ever find one. Also shown is the flash hider and with the rubber collar that was used which also had red, blue, green and IR filters. To use it properly, the lanyard lugs had to be cut off.

Rare stuff!

On 2/22/2021 at 7:53 PM, Jpage said:

Could not edit earlier post about an Applied Science Industries SDU-5E :

  Great post for info. I have one of these with the band of black paint.  Does this serve purpose?