A monthly technical report containing details of the following experiments:

Exp. 686 C.W. Spotting Set for Grand Fleet. 2000 to 5000 metres. The first model of this set is nearly complete and ready for test. See Fig. 1192 & 1193.

Exp. 683 Tonic Train Attachment to ½ K.W. Marconi Field Set. The accompanying photograph (see page 8.) shows the first experimental model of the attachment described in the Monthly Technical Report for November, Page 1.

Exp. 668 Report on Test of Murphy Generator with Constant Speed Windmill. The Constant Speed Windmill used was 12⅛” in length, and had a pitch of 9”. For a description of the Constant Speed Windmill see Monthly Technical Report for August, Page 22 and September, Page 20.

Exp. 677 Tf. Receiver Interference Tests. Experiments have been carried out on the interference of Tf Receivers in close formation flying.

Exp. 602 3 – Range Syntoniser. The experimental model has now been finished and calibrated. See diagram 1190 and photographs on page 15.

Exp. 608 Direction Finding. (General). A switch as suggested in the Monthly Technical Report for November, Page 4, has now been constructed and on test in the air. It consists of a wire resistance of 24 ohms with a selector switch on the cover. See wiring diagram No. 1159 and modified diagram No. 1191.

Exp. 608A D.F. Gear in Airships at East Fortune. The two ships intended to be fitted were the Rigid No. 29 (internal Keel) and the N.S. 7.

Exp. 608A W/T D.F. on Flying Boat F. 3 N 4236. The fitting of this boat has now been practically completed and is awaiting its air tests.

Exp. 608E Continuous Wave Direction Finding. With a view to determining the best form of transmission for use in W/T directional work some experiments are being undertaken with C.W. long wave working i.e. 5000 metres.

Exp. 666 Valve Tests. Tests have been made on the following valves: Ediswan “D”, Stearn “D”, Osram “C” and Marconi “V 24”.