Couldn't find mention of one on the forum so it's appropriate I share some pics.
Front
![](https://www.eevblog.com/forum/testgear/hp-8654b-10-520-mhz-sig-gen-light-teardown/?action=dlattach;attach=344068)
Rear
![](https://www.eevblog.com/forum/testgear/hp-8654b-10-520-mhz-sig-gen-light-teardown/?action=dlattach;attach=344070)
Top
Note the SMA spanner screwed to the chassis for the rigid plumbing.
![](https://www.eevblog.com/forum/testgear/hp-8654b-10-520-mhz-sig-gen-light-teardown/?action=dlattach;attach=344072)
Top under PCB
Hinged PCB swung away.....still connected.
![](https://www.eevblog.com/forum/testgear/hp-8654b-10-520-mhz-sig-gen-light-teardown/?action=dlattach;attach=344074)
Inside rear
![](https://www.eevblog.com/forum/testgear/hp-8654b-10-520-mhz-sig-gen-light-teardown/?action=dlattach;attach=344076)
Bottom
What appears to be a cavity oscillator take a large amount of the space in the enclosure.
![](https://www.eevblog.com/forum/testgear/hp-8654b-10-520-mhz-sig-gen-light-teardown/?action=dlattach;attach=344078)
It appears fully functional.
![Grin ;D](https://www.eevblog.com/forum/Smileys/default/grin.gif)
Last Cal 2005.
This unit has option 003 installed....Reverse power protection. It's a small self contained module seen on the right of Bottom image.
All that was needed was some sticker residue cleaning and the frequency range knob grub screws tightened.
Manual:
www.ue.eti.pg.gda.pl/~bpa/lab_klb/pdfs/08654b_manual.pdf18 Mb
Other than the MHz range selected there is no accurate display of the output frequency so a counter need be attached for accurate settings. There are/is some adjustment available for signal amplitude and user nulling for the moving coil meter.
A screenshot @ -3dB point of my SDS2304X. (~360 MHz)
![](https://www.eevblog.com/forum/testgear/hp-8654b-10-520-mhz-sig-gen-light-teardown/?action=dlattach;attach=344080)