I am wondering if the HP 8640 is the one i owned briefly. I had admired a friend's example and thought i better have one also. I bought one at a swapmeet and guess what, it didn't play. Looking at the manual, i decided i did not want to devote that much of my life to learning well that one instrument. I bought parts for it too. I lost my shirt on that little adventure.  Well, win some, lose some.

I was given this SG-297 FM sig gen 18 to 50 some MHz. It's about a one foot cube and weighs like kryptonite. It does have a stupendous attenuator which goes way below 1 uV which is what interested me. I had thought of a solution similar to Ray's, a freq divider to give me more HF band coverage. But thinking of the weight of this thing, i think the very best idea i can come up with, is to just pass it along.

-Hue Miller