Anyone with listings of WINDOW types?

**petertking** · 23rd August 2023, 08:04

Hi, I am trying to find out some details on two types of Window used in June 44 on Airborne ops. From the TNA I have a copy of tests done on six(?) British and American types in February 44, but the type ids used on the June ops bear no relationship to them. I am interested in type N (which was probably for use against Freya radar) and type M(B) which may have been a composite pack for use against both Wurzburg and Seetakt systems. I am looking for spill dimensions and numbers per pack, and pack weights if anyone has them. TIA

**Ian Brown** · 23rd August 2023, 20:50

The following comes from 'Confound and Destroy' by Martin Streetly.

Type N. Used against Wurzburg, Seetakt and FuG202. Dimensions of strips: 25cm x 0.55cm, 800 strips per bundle; 35cm x 0.55cm, 400 strips per bundle. Bundle weight: 9.5 oz (316.7 grammes)

Type MB. Used against Freya and FuG220. Dimensions of strips: 180cm x 5cm, 605 strips per bundle. Bundle weight: 29 oz (966.7 grammes)

I hope this gives you the information you need.

**JDCAVE** · 24th August 2023, 00:38

I have some material on window, perhaps not exactly what you are looking for. PP 155-156, AIR 41/13 Radio Countermeasures:

"On 6-May-1944, Bomber Command asked the Air Ministry to produce, as a matter of utmost operational urgency, a large quantity of Window on the presumed new A.I. frequency band 156-176 megacycles per second..."

These measures were never, however, put into effect because on 13-July-1944, a Ju.88 landed at Woodbridge, the pilot presuming he was over Holland. This aircraft had the S.N.2 Radar as well as Flensburg. Bomber Command was able to adjust their counter measures to the proper frequency of 90 megacycles per second, determining that the Type MB was "happily available" having been surplus to requirements after the invasion of Normandy.

Window type MB was first used on night of 23/24-July-1944 on a raid to Kiel and two nights later on a raid to Stuttgart. Experiments later showed that the maximum range of Litchenstein MB was reduced to 1/2 mile and S.N.2 was completely ineffective within the Bomber Stream although operators could be effective against bombers on the fringes of the stream.

For Oberhausen, 1/2-November-1944: Windowing was to be normal. The “Old type” or narrow type windowing was to start at 6^oE at 2 bundles per minute until 20 miles before the target and from there through the target and 20 miles past, 5 per minute and then 2 per minute to 4^oE, with new-type or wide-type from just before 6^oE to the target and back to 4^oE.

For Bochum, 4/5-November-1944, Normal - narrow type from about 3^oE to within 20 miles of target 2 bundles per minute. 20 miles either side of target 5 bundles per minute, 2 per minute to 4^oE. Broad one per minute 6^oE to 4^oE.

Jim