Rather by chance, a topic has arisen concerning many small differences in detail on the MA/V 250W and MA/V 400W lamps manufactured by GEC OSRAM:

- one starting resistor or two starting resistors
- one “zigzag” support or two “zigzag” supports
- different voltage specifications

This article could become a good overview if enough owners of these lamps would participate and post new photos of their lamps here.
The request would be: take new pictures in portrait format and include the lamp diagonally from bottom left to top right.
Please include the date code or insert it as a reduced image in the photo of the lamp. A page width of 1280 pixels for the narrow side would be favorable.
I'll just make a start now:



MA/V 250W , Code 92 (August 1957) , 230V-240V , two starting resistors in parallel circuit

Hello Olav,
Here are my two lamps:


https://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=12274&pos=10&pid=224759
250W: c.1955-1960 NATO Surplus a single arc tube holding spring and two parallel carbon resistor for one ignition electrode in the top.


https://www.lighting-gallery.net/gallery/displayimage.php?album=3934&pos=0&pid=224760
400W: c. 1955-1960 NATO surplus two arc tube springs one single carbon resistor and ignition electrode at the base.


I further did some research in the web:

400W

http://www.lamptech.co.uk/Spec%20Sheets/D%20MA%20GEC%20MAV400.htm
James' last generation of GEC lamp: 400W same as mine with the change from a brass to a nickel plated brass base

https://www.lighting-gallery.net/gallery/displayimage.php?album=search&cat=0&pos=25&pid=238406
400W: 1962 NATO surplus two arc tube springs one single carbon resistor and ignition electrode at the base.

http://lampenmuseum.de/details.php?image_id=1429
Rigo's 400W MA/V lamp, here the construction is mor similar to my 250W lamp with one single carbon resistor on the lamps top


250W
https://www.lighting-gallery.net/gallery/displayimage.php?album=search&cat=0&pos=22&pid=242199
A MA/V lamp from 1959 with a single ignition resistor in the bottom.

https://www.lighting-gallery.net/gallery/displayimage.php?album=search&cat=0&pos=39&pid=224827
A MA/V lamp from 1959 with a single ignition resistor in the bottom and nickel plated base


trying to find an evolution:
The newer lamps have the resistor at the base. The switch from brass to nickle plated brass was around 1962/1963.

Eventually the 250W got its second holding spring back.

best regards,
Alex

Hello Alex,

thank you very much for your work with the additions and tips. It's interesting to compare the individual variants within this lamp-design.

Best regards

Olav