Hello.  Before you add in your requirement and then click search, a little bit of advice on how to get the best out of this system.

Let us take the Marconi NT 204 Transmitter, known in the navy as the 640 as an example. When you click search, every page which contains the entry '640' will be returned to you.  Even if a returned page seems to have the obvious answer, be warned that on that page the name 640 may appear several times, each appearance giving separate detail about the transmitter. Therefore, for all returned pages it is better to approach the search as follows.  Open a returned page, then from the page menu bar choose 'EDIT' and then 'Find on this page'. In the find  box below, add in 640. Each and every appearance of 640 will be highlighted. All the details of the find are shown in the horizontal line attached to the 'find' box. Be sure to check the www.museum button for the search and not the WWW button.  Good hunting.