alignment generators ?

[jshorva65]

Another collector recently mentioned that B&K produced a generator similar to the 415 which was set up for 21 MHz IF systems. The model number was unknown so I'm wondering if anyone else has seen this and remembers its model number. I use harmonics of the 10.7 MHz sweep and external markers with my 415 but doing so will also generate marker pips at the difference frequencies so it takes some practice to recognize which ones are correct. I use a dry-erase pen to place a "dot" on the plastic screen cover of my scope at the locations of the useful markers during setup. I borrowed the "dots" idea from an old TV service course textbook which suggested using a crayon or grease pencil.