HP 8654B 10-520 MHz Sig Gen light teardown

[tautech]

Couldn't find mention of one on the forum so it's appropriate I share some pics.

Front

Rear

Top
Note the SMA spanner screwed to the chassis for the rigid plumbing.

Top under PCB
Hinged PCB swung away.....still connected.

Inside rear

Bottom
What appears to be a cavity oscillator take a large amount of the space in the enclosure.


It appears fully functional. 
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.pdf
18 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)

[bjcuizon]

Nice teardown and a great score!
For the sma wrench, don't you need a proper torque wrench when putting the rigid cables back in..Or does it really matter much as its just SMA connectors? (and not the precision 3.5mm and all that sort of stuff)

[tautech]

Nice teardown and a great score!
For the sma wrench, don't you need a proper torque wrench when putting the rigid cables back in..Or does it really matter much as its just SMA connectors? (and not the precision 3.5mm and all that sort of stuff)

I don't think SMA was very common back in 1977 so rather than have techs grapple with them and pliers  it was just easier to add a wrench under a screw on the chassis.

[bjcuizon]

I don't think SMA was very common back in 1977 so rather than have techs grapple with them and pliers  it was just easier to add a wrench under a screw on the chassis.

Hehe, it is assuming that the servicemen are the ones with the grey beards who just hold their tongue at a right angle and know when and where to stop turning the connector.

[xrunner]

Cool deal. What's that component mounted at an angle (a pot or switch?). Is it due to some sort of gear arrangement?

[TheSteve]

It looks like a beautiful unit - thank you for sharing. It might be time for a better camera though.

[tautech]

Cool deal. What's that component mounted at an angle (a pot or switch?). Is it due to some sort of gear arrangement?

It's the mode 3 position switch for the front panel meter. The switch itself is mounted inline with the shaft so only one shaft universal is needed. You can see the switch on the front panel to the left of the meter.

[hendorog]

That's a ripper, nice one Rob.

It looks like a beautiful unit - thank you for sharing. It might be time for a better camera though.

Regarding the images, no doubt he has shrunk them as I know he has a very restricted connection to the interwebs.

[TheSteve]

That's a ripper, nice one Rob.

It looks like a beautiful unit - thank you for sharing. It might be time for a better camera though.

Regarding the images, no doubt he has shrunk them as I know he has a very restricted connection to the interwebs.

Could be, it's a machine worthy of some nice hi-res shots, and looks to be in great shape.

[tautech]

That's a ripper, nice one Rob.

It looks like a beautiful unit - thank you for sharing. It might be time for a better camera though.

Regarding the images, no doubt he has shrunk them as I know he has a very restricted connection to the interwebs.

Could be, it's a machine worthy of some nice hi-res shots, and looks to be in great shape.

Rog is quite correct, they've been compressed from 5 Mb.

At some stage it's had a bump and one of the rear rails has a slight bend  and the pointer lug has been broken off the amplitude selector (visible in the pics) but neither affect functionality. 

Anyways, I'm very pleased with the HP Sig gen, other that my SA it's the highest frequency gear I have......as yet.

[wilgil]

You soooooo owe me now......

[tautech]

You soooooo owe me now......

I do.