HP-8569 Spectrum Analyzer Repairs

[AF6LJ]

I'm not real happy about this

yeah, I bet

I am so sorry Sue.  I know it is a lot of work, but are you planning to relink the thread?  These kinds of threads are sooooo useful for people later trying to fix similar gear.

I still have one more to rebuild, maybe two if I have enough parts....
I may repost the pictures then.

[bitseeker]

Ooh, more rebuilds. Looking forward to it!

[AF6LJ]

Ooh, more rebuilds. Looking forward to it!

The next rebuild will start next month with new pictures.

[bitseeker]

Thanks for the update. Looking forward to it.

[WastelandTek]

yayyyyyyy!!

new pictures!

[AF6LJ]

I am finishing off a project now that is taking up a lot of valuable bench space. (Heathkit HL-2200 linear amplifier). This amplifier has been giving me fits on the ten meter band. Looks like I have a bad input circuit cap, parts ordered and soon enough this project will be done.


Status Update;
We left off with the sweep time knob being stuck on the shaft. This was stopping the removal of the front panel dress plate. and the rest of the rebuild process of the second front panel.
I picked up two left hand drill bits and a 4-40 (right hand) tap) I was able to free up the hex head set screws in the knob, with the threads in the knob insert suffering little or no damage.
SO...
This repair will begin with the remaining disassembly of the front panel module.
I have learned a few things from the assembly of the last front panel module and this one should go with a minimum of rework to get things to align up right.
Here is a sample of what is in store


And the back side....


These were taken from the first rebuild.
I do need to get the picture size down to something like 1024 X 768....

[bitseeker]

Interesting mechanicals back there. I wonder when 3D printing will become a staple of the bench to keep these vintage instruments going.

[AF6LJ]

Quote from: bitseeker on Today at 12:02:51 PM

Interesting mechanicals back there. I wonder when 3D printing will become a staple of the bench to keep these vintage instruments going.

The knobs are fragile, but the switch rotors inside are robust.
The problem is the little metal contacts get lost.

I would love to find a source for those little contact fingers.

[bitseeker]

Yeah, not so easy replacing little metal bits of various kinds. I suppose one could learn to work with spring steel, but I have no idea what that involves to cut, form, etc.

[WastelandTek]

are there pics up there that I am not resolving for some reason?

[bitseeker]

Reply #80 has pics, but the one for #82 seems not to be set for public viewing.

[WastelandTek]

hmmmm, I better look at my noscript settings, all the other pics on this forum are working for me

[AF6LJ]

are there pics up there that I am not resolving for some reason?

I use to post all my pictures to Photobucket...
Now I keep them in my Google album.
Photobucket decided they wanted to charge an arm and a leg for the bandwidth used by people viewing linked images.

[AF6LJ]

Yeah, not so easy replacing little metal bits of various kinds. I suppose one could learn to work with spring steel, but I have no idea what that involves to cut, form, etc.

It's not really that bad, although this time I get to do a lot more of gluing those contacts in place. I have been thinking about drilling and tapping the locations where the broken hot stakes are at. Using 0-80 screws as clamps to hold the contacts in place while the glue cures.
We shall see how this goes.

[VK5RC]

I have a friend who is a dentist, he is a glue and material 'king', some wisdom he passed on was that he often uses a tiny sand blaster (about pencil sized)  to lightly etch materials before gluing.

[AF6LJ]

I have a friend who is a dentist, he is a glue and material 'king', some wisdom he passed on was that he often uses a tiny sand blaster (about pencil sized)  to lightly etch materials before gluing.

You almost have to ether chemically etch or manually etch the surface if you want success with glues. Making the surface a little tacky also helps.

[AF6LJ]

Work has begun on the second HP-8569B front panel module. This one isn't as bad off as the last one, I think there is only one switch contact assembly that needs repair.
As you remember I had to drill out the two set screws in the sweep time / div knob and chase the threads with a 4-40 tap.
Today I have removed the PCB assemblies from the front panel plate and removed the dress plate.
So here is where we are at.



On this unit the Frequency span switch is missing a set of contacts. This requires the rotary switch on the right must be completely taken apart and the rotor prepared to have the switch contact (I managed to save several) glued in place.
With that switch removed I can inspect the input atten., and IF gain switches for missing contacts. There is an issue with the vernier knob, the pot works but the on screen readout isn't working reliably. The contacts for the rotary encoder are there, my thoughts are some adjustment of the wheel that holds the contacts may be in order.

More tomorrow, I need to dig the boxes of parts from the other front panels out of storage.
Be prepared for lots of fresh pictures.

[xrunner]

Cool - pics are good eye candy. 

[WastelandTek]

does anyone know which script is associated with these pics...I'm not resolving them and the rest of the site works fine

[AF6LJ]

I am using FireFox and they look fine.

[Yansi]

Hi guys, would you mind please NOT to link externally hosted pictures into the forum? What I now  see is only a bunch of cats from a f'kin photobucket instead.

[AF6LJ]

Hi guys, would you mind please NOT to link externally hosted pictures into the forum? What I now  see is only a bunch of cats from a f'kin photobucket instead.

The photobucket account is gone, they no longer support external linking without a costly subscription. That is unfortunate. I will continue to use my google photos account, since this site doesn't support uploading high resolution photos.

[WastelandTek]

I am using FireFox and they look fine.

Yes, I am using firefox as well, something in my suite of script/ad/track blockers is nerfing your photos.

Where are you hosting them?

[AF6LJ]

I am using FireFox and they look fine.

Yes, I am using firefox as well, something in my suite of script/ad/track blockers is nerfing your photos.

Where are you hosting them?

Google Photos.

[bitseeker]

The photos appear OK for me on Firefox with uBlock Origin. The images come from googleusercontent.com. Check if your blocker is preventing content from that domain from loading.