3" disks for 8566A/B, 8568A/B on HP 9000 Series 200 Computers - Any interest in images?
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Hello Forum,
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I think I posted this before but no harm in bumping...
Together with an HP8568B, I got a number of 3?-inch disks:
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85863-10027 Rev C : 85863A Opt 630 Basic Software Library
08568-10004 Rev A: HP 8568B Spectrum Analyzer Operation Verification
08568-10004 Rev A: BASIC Operation Verification for 8568B
85863-10027 Rev B: 85863A Basic Software Library for 8566A and 8568A Opt 630.
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All disks (C) 1984 and two of them marked "For HP 9000 Series 200 Computers with Basic 2.0 or 3.0 O/S
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Any interest in images? I do not know if any data remains on them.
If so, How to read and make images on a PC running XP or W7?
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Cheers
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Ulf Kylenfall
SM6GXV
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Re: HP 8673D synthesized generator - need replace RF out connector - partial front panel removal suggestions
8673D is making RF and working as expected. No more leveling problems. Fan (after first minute or so) sounds OK.
Remaining problem (which existed before, and I will address in future) is very low output in the 10 MHz - 2 GHz range (which uses the lower section.) This problem has existed for the time I've had the unit, and I haven't wanted to tackle repair (as I also have HP 8660 series generator and nowadays a TinySA can reasonably suffice).
Now that I have experience with the unit's (partial) disassembly (and some tools to help move the literal boat anchor around in the workshop), I'll revisit the 10 MHz - 2 GHz issue at some point and report on that adventure.
Thanks for the bandwidth!
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Re: HP 8640b range switch
Mark,? i found some spare HP switches on ebay that used those same contacts.? I cut them out and epoxied to my range wheels.? Loctite makes a clear 2 part plastic bonder that works very well and because its clear, is not very noticeable installed.
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-A
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Re: HP 8673D synthesized generator - need replace RF out connector - partial front panel removal suggestions
Successfully swapped the front panel connector (it's replacement was a used pull.) The main challenge is that the front panel PC board comes fairly close to the back side of the front panel connector, making it a little difficult to get a decent grip on the rear nut. Turns out a 1/4" drive, 1/2" thin wall hex socket on a 1/4" screwdriver-style socket driver handle was sufficient once the front panel assembly was rotated sufficiently around to accommodate the handle.
Now begins reassembly (reverse of disassembly, as the HP manual says.....) - the only steps that should take any special care are getting the top-to-bottom semirigid lines (2) back into position, and avoiding trapping any of the top/bottom section interconnect wires while bringing the two halves back together.
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Re: HP 8673D synthesized generator - need replace RF out connector - partial front panel removal suggestions
Decided "go for broke" --- gently lowered the unit onto the table in front of the shelving where it lives (and onto a piece of carpet material), turned it on it's side (3.5mm front panel connector towards bottom - a better choice would have been 3.5mm front panel connector towards top), and continued fastener removal (in many small labeled bags!)
Got to the point where the two halves are split, but not physically separated.
There are numerous wires (towards the front only) connecting the two halves; only two are UT141-type semi-rigid line (RF to and from the lower unit, I believe.) There appears to be enough slack in the wires (except for the two UT141-type semi-rigid lines) to allow about 100mm of separation without unplugging or unsoldering wires (which represents most of the steps involved in separating the two units by service manual.)
Getting to this stage required removing fasteners along the left and right sides that appeared likely to hold the front panel of the upper section in place, as well as fasteners along the sides that join the two halves. The (diagonal, right side) upper fastener at the front was partly obstructed by a U shaped aluminum section (about 5mm radius). I used small diagonal cutters to chew away some of that until I could remove the fastener. The material turns out to be part of the internal cover that isolates the two units, except for an open area near the center/front. I do not think my small cutting will cause problem.
At this point, the front panel of the upper section would still not separate from the body. Along the back of the unit (between the two units) was a span of thin metal (like top and bottom covers, same type of finish, decorative style) with two screws; I removed that piece (exposing the gap between the two units at the rear), and with this, the two units began to move independently, so I focused back to the front panel separation.
On the next step, I removed the decorative trim from the top of the upper front panel (thin screwdriver to pry away the plastic trim piece); under there were three more fasteners that I removed. Once these were removed, the front panel showed some more possibility of independent movement but still was stuck in position.
At this point (with the rear mid-point cover removed and the two units beginning to move independently), I began separating the two units, but discovered that the two semi-rigid (UT141) hardlines connecting the two halves was preventing much movement. I removed the 3.5mm male connectors from the upper unit termination (one of the two switches alongside the output attenuator). This required temporarily removing one end of two of the local (terminating both ends between the two switches) UT141 hardlines so that I could get better access to one of the two top-to-bottom hardline connectors. Once both of those connectors were removed from their switches (on the top side; no attention to the bottom side of the two cables), I was able separate further the two units (requiring careful steps to navigate the two now-free male hardline connectors.) Although I took some pictures, I will consult the service manual during re-assembly because it is possible to reverse the two top-to-bottom UT141 hardlines.
Once the two halves were separated enough to allow access to the bottom front of the upper section, I found no decorative trim, but three more fasteners of the same type, which I removed. I also saw several threaded (like machine screw end) visible along the same bottom front area, but fortunately these do not impede separation.
At this point the front panel assembly can move freely (still constrained by numerous wires) from the upper unit body, maybe 50mm clearance possible for access to the failed connector through what would be the bottom and side of the unit nearest the connector. The attachment of the internal connector is a simple hex nut, like used on old style potentiometers.
I believe (tomorrow, hopefully) I will be able replace the 3.5mm male connector from the front panel (remove both ends of the UT141 hardline connecting to the output attenuator.
Two photos are attached, one of the partially separated units, and other close-up of the 3.5mm-type switch connectors that are temporarily removed.
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Re: HP 8673D synthesized generator - need replace RF out connector - partial front panel removal suggestions
(Yves - I now see from the picture - you were able restore operation by adding component to the existing connector? In my case, the internals of the connector are damaged so my attempt to add component was not successful - very poor RF path resulted. Sorry for the mis-understanding.)
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Re: HP 8673D synthesized generator - need replace RF out connector - partial front panel removal suggestions
Thank you, Yves - I appreciate your information and agree that the unit is very nice tool (although very heavy!). Fortunately, this unit appears to still work internally, as the problem of leveling/output seems isolated to the periphery of the system, not the internals.
I do not directly see the need to separate the assemblies, provided that I can physically move the upper unit front panel forward slightly to gain access (working inside the gap between the bottom of the relocated upper unit, and the fixed lower unit, it seems access to the mounting nut for the connector should be accessible.
Do you remember what path you followed to reach the connector nut behind the upper unit front panel?
Thank you again!
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Re: HP 8673D synthesized generator - need replace RF out connector - partial front panel removal suggestions
Hi Dave,
I own an 8673D and I'm very satisfied with this generator; it performs quite
well.
I was able to get it back in exchange for another working instrument,
however, this 8673D was considered DEAD.
After several repairs and... several weeks later, I was facing the same
problem as you: separating the two stages to gain access to the 3.5mm
connector I wanted to replace.
Unfortunately, I wasn't able to separate them.
Let's just say I didn't try too hard, but I still removed or freed all the
cables and semi-rigid cables connecting them, and I couldn't find a way to
separate the two front panels.
I thought it was the central screws that were blocking everything.
But according to the procedure you attached, it seems the central screws
weren't involved in the disassembly.
So, I don't know what was preventing the separation.
All the metal support clips were removed.
In my case, it was the external part of the 3.5mm connector that was
slightly damaged.
I had corrected the connector with an exacto, but it was by installing a
3.5mm connector extension that I resolved the problem.
This 3.5mm connector came from a defective (non-repairable) module that
fitted an 83480A.
Since then, it has remained stable and meets specifications.
If you ever find the correct procedure, I would be interested to know it.
Yves
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HP 8673D synthesized generator - need replace RF out connector - partial front panel removal suggestions
My adventure fixing up my workshop's RF gear brings me to the last repair, the heaviest unit (94 pounds, and I'm older now than when I put it in position!)
The HP 8673D synthesizer uses a 3.5mm male panel connector (used on some other HP units supporting K-band). On this 8673D, at some point someone glued (?) a SMA female-female adapter into the 3.5mm male connector, and subsequently the adapter was sheared off, leaving half it's corpse in the 3.5mm male connector. I tried holding a spare SMA jack in place with a copper pipe cap, however, the RF path is impaired enough with this scheme that return losses badly confuse the leveling loop (otherwise the unit appears to function without errors.)
I have a replacement connector (08673-60040 is the HP part number) in hand.
I have service manual in hand (likewise quite large/heavy).
The procedure for replacing the (A4J1) connector isn't specifically called out, however, it appears the normal course of action is to remove the front panel assembly, gaining access to the back side of the connector. Removing the front panel, like most significant service procedures described in the service manual, begins by "separate the two units". I've attached photo of the relevant start of service sheet A pertaining to disassembly for front panel removal.
My idea is this - the front panel (A4) may (hopefully) only need to be moved slightly forwards (enough to get access to the back side of the RF output connector.) It appears that removal of the four internal screws that hold the front panel casting to the top/bottom internal structure (runs the length of the left and right sides) would allow the front panel to be moved forward away from the body of the unit (I don't know if there is a screw along the bottom front of the top section rendering this idea moot).
Although there are a number of connections (referring to service manual service sheet A), only one appears to be the semi-rigid output coax, and it can be removed from it's top connection (attenuator) easily (the cable cable would then come away with the front panel pulled forward.)
So, looking for any comments, suggestions, observations (and of course can supply any additional images that might be helpful.)
Dave
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Switched attenuator issue
I've noticed excessive through attenuation with my HP attenuator set (8497K / 8494H).
The repeatability was out of spec. After switching there would be a difference of 0.1 to 0.2dB.
I tried IPA on the RF relay switch contacts with no effect. I was hesitant to try anything more aggressive but with little to loose I applied Deoxit Gold ... and it fixed the problem completely.
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The spec for through attenuation is 0.4dB + 0.09dB/GHz & 0.6dB + 0.09 dB/GHz. The repeatability is now much better than spec.
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(I'd already replaced the o-rings)
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Re: HP 8640b range switch
Hi,
I bought one British made last year with obviously such missing ones, (not falling from the body either Mark!) and was also prepared to work there. Then another one presented itself (US made) cheap here in France. What could I do? I bought it and it happens that it's working fine. Even the plastic gears are good. So I neglected the other but I will do it. They are wonderful stuff. Mine have both the 1 GHz option.
Do tell us how it's going Mark
Renaud
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Re: HP 8640b range switch
You can count missing contacts by counting the locations on the rotor where the little plastic posts are broken off.
Dave Wise
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On Mar 10, 2025, at 10:18 AM, G H via groups.io <gkhoefer@...> wrote:
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Renuad,
Those are all great places to start. I have one of these units and I used the technique described on these articles. The epoxy/glue option works very well. I did this on all of the wipe contacts whether they were ready to separate/fall off or not. Good
insurance down the road for the original ones to stay in place.
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Re: HP 8640b range switch
Renuad,
Those are all great places to start. I have one of these units and I used the technique described on these articles. The epoxy/glue option works very well. I did this on all of the wipe contacts whether they were ready to separate/fall off or not. Good insurance down the road for the original ones to stay in place.
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Re: HP 8640b range switch
Hello Mark,
Indeed there's a lot on the net about those.
Here are some:
Good luck!
Renaud
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Re: HP 8640b range switch
There are some good articles on the Internet regarding this problem.
Also there is a web site for a company that offers serving of these units, for a price. You ship the entire unit to them and once repaired they ship it back.
Start up your favorite Internet search engine and fire away.
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Re: HP8510C TRL Calibration
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Ian,
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The owner is very knowledgeable about them & will answer technical questions.
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Bill Higdon
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Thats better, hopefully someone will recognise the issue.
Picture is still a bit fuzzy, though I can easily see the two
lines at the top of the screen, the second showing the error.
The other displays, with negative (black) text on a bright
background, don't come out too well.
Best Regards.
Dave 'KBV
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Hi to the group new to this group I have an HP 8640b the frequency range switch has dropped some of its contacts and looking with the times 30 loop on the plastic discs it looks like I'm missing a couple of contacts that I could not find inside the chassis anybody have any information on how many contacts on each of the three discs that are inside that machine appreciate any help thank you
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I saw three and ordered two to have a spare.? Since I have three of this meter and now know about how they can fail I can just replace them as needed.
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On 3/9/2025 3:39 PM, Razvan Popescu via groups.io wrote: Hi Peter,
If I am not mistaken there are 2 Omron relays on the board. If one
failed maybe the other one will fail soon so if you make an order and
have the unit open it is better to replace both.
Regards,
Razvan
On 09/03/2025 20:17, Peter Gottlieb via groups.io wrote:
I have tracked this down to K104 and confirmed by bench test the relay
has a bad side and won't make continuity to the DC high range
attenuator.? With the relay removed I can jumper pins 9 to 13 and get a
voltage reading on the higher range which confirms the rest of the meter
works.
This is an Omron G6AK-274P-STLT-US-5VDC which is commonly available.? I
will get one on order from Mouser.
Peter
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