[Simh] SIMH Raw disk usage

[richard at richard-harper.me.uk]

Hi,

I have managed to obtain a raw disc image for one of the SIMH emulators. 
   This is a bootable disc apparently.  I can attach the disc but when I 
boot nothing happens.

Digging around in the 2012 SIMH FAQ I found this sentence:

“Utility programs are available to convert raw data streams to SIMH 
format.”

Does this mean that I  cannot use a raw disc image in SIMH ?

If this is the case where do I get a conversion program for a DGC 4048 
disc ?

Thanks,

Rich