Re: HP 8116A woes with E42 error
I did check the supplies. Sorry I forgot to mention that. If I remember correctly the +15 V supply was off, and it wasn't off by much. It was in the millivolts range if I recall. I was able to get that back into range with no trouble.It didn't catch me off guard as I would expect these to drift out of range slightly over time.
I will double check these values again this evening before I move on to recapping a Monsanto 101A counter. Like this nixie tube counter too. Pretty neato.
Thanks,
David
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Re: HP8563E-Damaged red coax from A4 PCB-Is it easy to replace?
I'll also give the warming up trick a try as well and I'll check the continuity as well. Thanks.
David.
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Re: HP8563E-Damaged red coax from A4 PCB-Is it easy to replace?
George,
I will confirm if there is a connector on the other end and the exact length this coming weekend. Thank you.
David.
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Re: HP8563E-Damaged red coax from A4 PCB-Is it easy to replace?
Hi David
Having looked at the photograph I would first try slightly warming the cable and then using my thumb and a finger try to roll the damage out of the coax.
?
SMB connectors are not normally used in high frequency RF or critical circuits so a little cable damage may not matter.
?
To remove an SMB pull on the sleeve nearest the matting connector as they are a latch fitting.
?
G Edmonds
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Re: HP8563E-Damaged red coax from A4 PCB-Is it easy to replace?
Hi David
This is an SMB connector.? The cable is almost certainly 50 Ohms impedance as is the SMB connector.
The red is just for identification, does it have connectors on both ends?
What is the length?
G Edmonds
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Re: HP8563E-Damaged red coax from A4 PCB-Is it easy to replace?
Thank you for your replies so far.
Please find attached a photo of the connectors and the damaged coax cable (Red). If I was to buy cable it is important to buy the correct type so that it's the correct impedance and also so that it fits any connector properly. I hope you can help me further. Thanks
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Re: HP8563E-Damaged red coax from A4 PCB-Is it easy to replace?
Hi David
I suspect that you are asking for a cable using SMB connector/s.
Sugest that you photograph it and post the photograph.
I have some SMB made up cables
G Edmonds
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Re: HP8563E-Damaged red coax from A4 PCB-Is it easy to replace?
There is no such thing as a push on SMA , the connector you are referring to is more than likely a SMB connector which are common in HP equipment to connect IF and low frequency signal lines, crimp tools you can find on ebay and the cables and connectors you
can get at digi key , mouser, newark or similar places but you can find the cables are common and you can find them on ebay?
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On May 29, 2022, at 11:51, David via groups.io <david@...> wrote:
?I am reassembling my HP8563E SA and I have found a red coaxial cable (approx 2.7mm diameter) that connects to the A4 PCB that has compression damage to the insulation. It has a right angle push on type SMA connector. I don't have the exact length
measured yet, and I need to confirm if it has continuity. However, ideally I would like to replace the cable if possible. The problem is I do not have the tooling available to make a cable up myself. Is a crimping tool available for a reasonable price? If
so, which one? What is the type of coaxial cable used? Are these right angled push on SMA connectors still available and if so does anyone have a part number and supplier information they can share. Is there anywhere in UK/Europe I can get a single cable made
up? Or does anyone have a spare cable they don't need? Thanks.
David,
Hemel Hempstead UK.
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Re: HP 8116A woes with E42 error
Did you check the supplies? You mentioned checking a bunch of stuff,
but not that. I've fixed a couple of these (I think), and the
problem was simply a bad negative supply, if I recall correctly. In
any case, check supplies if you haven't already.
--Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 5/29/2022 08:59, Swiss via groups.io
wrote:
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Show quoted text
Hello everyone.
Long time lurker / never poster.
Waned to see if anyone may have some ideas on an issue that I am
having with an 8116A? function generator.
The output of the unit slowly started to become distorted over the
last year in every waveform form mode. The distortion would come
and go. Intermittent so to speak. One day it would work fine, and
the next it would be unusable. It looks like it has finally
broken, still comes good every now and then, but it seems to be in
a consistent failure mode now.
I've followed the troubleshooting steps in the service manual
starting in 10.4. The results are as follows:
The output at test point 4 is not distorted below 999 mV. I also
checked the pins on U401, pin 18 and pin 19 and all looks well
according to the manual. Once I increase the amplitude above
1.00Vp-p, TP 4 starts to become distorted for both the triangle
and square waveforms. Amplitude - vernier control voltage is
within spec.
I removed U401 to reseat it just to make sure there wasn't a bad
connection there. Checked the current at pin16 and measured 2.366
mA. 2.5 mA is what it is spec'd for.
The current mirror on the output of U401 (Q401A and Q401B) is what
concerns me the most. The measurements are as follows:
With the unit set @ 4.00V? amplitude output: (I can't find the
datasheet on this matched pair, so I don't know if I have the
naming convention correct below) The tab on the can is pointing to
the right <-- as modeled by MAT01, or MAT03 matched PNP.
? C(2)? ? ? ?|? ? B(2)? ? ?|? ? ?E(2)
3.1090 V? ?3.9568 V? ? 4.7701 V?
? C(1)? ? ? ?|? ? B(1)? ? ?|? ? ?E(1)
3.8617 V? ?3.9564 V? ? 4.7746 V?
@ 999mV
? C(2)? ? ? ?|? ? B(2)? ? ?|? ? ?E(2)
3.1081 V? ?3.9626 V? ? 4.7722 V
? C(1)? ? ? ?|? ? B(1)? ? ?|? ? ?E(1)
3.8625 V? ?3.9626 V? ? 4.7766 V
The offset-vernier control-voltage is slightly out of spec for the
negative side. Although I don't think this is my issue, however it
might be related.
WIth offset set to -5.00 V, I measured 3.3122 Vdc. This is 62 mV
out of spec.
WIth offset set to -7.00 V, I measured 2.0840 Vdc. This is 34 mV
out of spec.
I diode checked all the output transistors from Q501 to Q513 and
didn't see any usual values. No shorts or opens. Just some caps
charging.
I also checked the A2 board for offset control and the DACs and
didn't find anything out of sorts there either.
When switching from 999mV to 1.00V, it seems that the reed
switches K2 and K3 are the only ones that change. If any of the
circuits were pulling down the signal at TP4, I would suspect the
issue to be on K3. However, the main output from the front panel
is still distorted regardless of the reed switch positions.
The unit has no negative offset control. Only positive offset
control. I can add the full positive DC offset, and the signal
will rise above ground and the waveform will not be distorted.
Looks nice and clean above ground reference.
I do have another good working 8116A that I could use to compare
measurements from, but i'd rather not probe around in it unless I
really have too. I want to try and keep this unit as I like the
8116A. Don't want to turn it into a parts machine unless I have
too.
So I guess my question is, should I try to replace Q401, or is it
possible that the issue could be else where. Was wondering if
someone here had experience with these units, and if there are any
common failure points with this error.
Sorry that I made this so long.
Thanks for the help,
David
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HP8563E-Damaged red coax from A4 PCB-Is it easy to replace?
I am reassembling my HP8563E SA and I have found a red coaxial cable (approx 2.7mm diameter) that connects to the A4 PCB that has compression damage to the insulation. It has a right angle push on type SMA connector. I don't have the exact length measured yet, and I need to confirm if it has continuity. However, ideally I would like to replace the cable if possible. The problem is I do not have the tooling available to make a cable up myself. Is a crimping tool available for a reasonable price? If so, which one? What is the type of coaxial cable used? Are these right angled push on SMA connectors still available and if so does anyone have a part number and supplier information they can share. Is there anywhere in UK/Europe I can get a single cable made up? Or does anyone have a spare cable they don't need? Thanks.
David,
Hemel Hempstead UK.
|
HP 8116A woes with E42 error
Hello everyone.
Long time lurker / never poster.
Waned to see if anyone may have some ideas on an issue that I am having with an 8116A? function generator.
The output of the unit slowly started to become distorted over the last year in every waveform form mode. The distortion would come and go. Intermittent so to speak. One day it would work fine, and the next it would be unusable. It looks like it has finally broken, still comes good every now and then, but it seems to be in a consistent failure mode now.
I've followed the troubleshooting steps in the service manual starting in 10.4. The results are as follows:
The output at test point 4 is not distorted below 999 mV. I also checked the pins on U401, pin 18 and pin 19 and all looks well according to the manual. Once I increase the amplitude above 1.00Vp-p, TP 4 starts to become distorted for both the triangle and square waveforms. Amplitude - vernier control voltage is within spec.
I removed U401 to reseat it just to make sure there wasn't a bad connection there. Checked the current at pin16 and measured 2.366 mA. 2.5 mA is what it is spec'd for.
The current mirror on the output of U401 (Q401A and Q401B) is what concerns me the most. The measurements are as follows:
With the unit set @ 4.00V? amplitude output: (I can't find the datasheet on this matched pair, so I don't know if I have the naming convention correct below) The tab on the can is pointing to the right <-- as modeled by MAT01, or MAT03 matched PNP.
? C(2)? ? ? ?|? ? B(2)? ? ?|? ? ?E(2)
3.1090 V? ?3.9568 V? ? 4.7701 V?
? C(1)? ? ? ?|? ? B(1)? ? ?|? ? ?E(1)
3.8617 V? ?3.9564 V? ? 4.7746 V?
@ 999mV
? C(2)? ? ? ?|? ? B(2)? ? ?|? ? ?E(2)
3.1081 V? ?3.9626 V? ? 4.7722 V
? C(1)? ? ? ?|? ? B(1)? ? ?|? ? ?E(1)
3.8625 V? ?3.9626 V? ? 4.7766 V
The offset-vernier control-voltage is slightly out of spec for the negative side. Although I don't think this is my issue, however it might be related.
WIth offset set to -5.00 V, I measured 3.3122 Vdc. This is 62 mV out of spec.
WIth offset set to -7.00 V, I measured 2.0840 Vdc. This is 34 mV out of spec.
I diode checked all the output transistors from Q501 to Q513 and didn't see any usual values. No shorts or opens. Just some caps charging.
I also checked the A2 board for offset control and the DACs and didn't find anything out of sorts there either.
When switching from 999mV to 1.00V, it seems that the reed switches K2 and K3 are the only ones that change. If any of the circuits were pulling down the signal at TP4, I would suspect the issue to be on K3. However, the main output from the front panel is still distorted regardless of the reed switch positions.
The unit has no negative offset control. Only positive offset control. I can add the full positive DC offset, and the signal will rise above ground and the waveform will not be distorted. Looks nice and clean above ground reference.
I do have another good working 8116A that I could use to compare measurements from, but i'd rather not probe around in it unless I really have too. I want to try and keep this unit as I like the 8116A. Don't want to turn it into a parts machine unless I have too.
So I guess my question is, should I try to replace Q401, or is it possible that the issue could be else where. Was wondering if someone here had experience with these units, and if there are any common failure points with this error.
Sorry that I made this so long.
Thanks for the help,
David
|
On Sun, May 29, 2022 at 03:51 AM, Bill Higdon wrote:
It's a little known fact that we have seen Google engineers tinker with Lack tables since way back in 2009." https://wiki.eth0.nl/index.php/LackRack
Yes... yes it is! I'm not saying I have enough style to avoid this; but, I don't smoke as much of that stuff as some Google engineers might (whatever a Google engineer might be.) Fortunately, equipment racks turn up here, and Ikea is far away.
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Re: Limits of the Port Extension on the Cal screen for calibrating at end of cable
Dr. Kirkby: " You will need to slow the sweep speed down, below that automatically chosen for you. Otherwise the frequency of the oscillator will have shifted outside the passband of the receiver by the time it gets back to the receiver. This is well documented in one of the HP Application notes"
-----------
Attached is an example.
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This might be an interesting idea for small rack mounts
"The LackRack is the ultimate, low-cost, high shininess solution for your modular datacenter-in-the-living-room. Featuring the (side table) from Ikea, the LackRack is an easy-to-implement, exact-fit datacenter building block. It's a little known fact that we have seen Google engineers tinker with Lack tables since way back in 2009." https://wiki.eth0.nl/index.php/LackRack
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Re: 53181A 3 GHz prescaler from China
I saw a clock multiplier module on eBay the item number is 362887003547 - P1: Input Port (Input 2~50MHz, Minimum Input Voltage 100mVp-p) SMA Interface. - P2: Output Port (Maximum 150MHz) SMA Interface - P3: Power Supply Port (3.3V~5V) Configurable for 2x, 3x, 4x, 5x, 6x, 8x, and some others Might be useful for getting 40 MHz from 10 MHz for your applcation. I was thinking to try this to get 40MHz from 10MHz ref for ADI Pluto SDR module. I purchased one but have not tried it yet. I have no connection to the seller. -Eric Haskell
?
?
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This fellow rebuilds the 8649B range gear assembly. ?I sent mine in and got the rebuilt back soon. ?Can¡¯t recall cost. ?
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If I'm not mistaken, these fingers are the same ones that are on those disks:
https://www.ebay.com/itm/125225534497
Thanks,
Barry - N4BUQ
From: "Tom Lee" <tomlee@...>
To: "HP-Agilent-Keysight-equipment" <[email protected]>
Sent: Saturday, May 28, 2022 4:10:51 PM
Subject: Re: [HP-Agilent-Keysight-equipment] HP8640B no rf out
If you are unable to find exact replacements, many have successfully
improvised substitutes. I've used the contact fingers from cast-off
solderless breadboards and Lothar's method of screwing them down.
They don't look pretty, but they work fine.
Good luck, The self-disassembling contact fingers is a fairly common
problem in a certain vintage of HP products (HP8557A/8558A, just to
name a couple others).
--Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 5/28/2022 08:06, Donald Prins wrote:
Hi Ellud,
Can you tell me where one can obtain those wipers? I have a
HP8640B that is missing 3 in total on the FM/RANGE switches. Your
help will be much appreciated.
Donald?
PE1AHJ
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Re: Limits of the Port Extension on the Cal screen for calibrating at end of cable
On Sat, 28 May 2022 at 00:50, Karin Johnson < karinann@...> wrote: I realized a couple of hours after sending the initial post, that I was incorrect with associating Calibration with the Port Extensions.
Here is, I hope a better explanation of what I am trying to do.
First off the measurement frequency is 14 MHz.? So not too beyond the capability of the 8753C.
? A wavelength of roughly 20 m.
I want to place the measurement plane at the end of a 100 foot length of RG213.? ? Em, wish you would work in metric! Let's call that 30 m. So your cable
is 1.5 wavelengths long, which is far from unusual for a VNA.? My 20 GHz
VNA has cables that are 600 mm long, so 40 wavelengths. It calibrates okay, with cables 40 wavelengths long.
So I place the SOL standards, one at a time at the
end of the cable.? Supposedly the 8753C measurement plane is now at the end of the cable.
? More precisely, at the reference plane of the connector on the end of your cable. Depending on the connector, the reference plane may or may not be near the end of the connector. The reference plane of the connector is the outer conductor mating plane. In the case of a female N, it is well inside the connector - roughly 8 mm, as I measured with a bit of wire and ruler next to me. ????
Now I can take S11 measurements relative to the measurement plane at the end of the cable.? My question should have been
" Is there a limit in terms of how long a cable can be before this calibration technique fails."
This is probably related to the storage of the cal correction factors in the memory of the 8753C.? Is it via floating point numbers, or integer numbers?
How large or small can the calibration correction values be???
? The calibration factors to be entered into the VNA include the offset delays (lengths) of the calibration standards. They are only of the order of mm. The fact your cable is 100 m long does not change those numbers.
I seem to be able to obtain valid data using this technique, but wanted to ask on the Keysight forum with some of the folks who actually designed
the instrument.? I think Dr. Joel it still active there.? ?
I would certainly slow the sweep speed down, and see if that changes your results. If it does, then you have a problem.
?
My rant about not being able to login to the Keysight forums still exists.? It seems their login/validation screen seems broken.
At one time I had an account over there but they have seemed to have changed the supporting vendor for the forum sites.
I wish Keysight would just use some open-source forum software, instead of all this proprietary crap, which they keep needing to change.?
As always,
Regards,
Karin Johnson
? Dave
|
If you are unable to find exact replacements, many have successfully
improvised substitutes. I've used the contact fingers from cast-off
solderless breadboards and Lothar's method of screwing them down.
They don't look pretty, but they work fine.
Good luck, The self-disassembling contact fingers is a fairly common
problem in a certain vintage of HP products (HP8557A/8558A, just to
name a couple others).
--Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 5/28/2022 08:06, Donald Prins wrote:
toggle quoted message
Show quoted text
Hi Ellud,
Can you tell me where one can obtain those wipers? I have a
HP8640B that is missing 3 in total on the FM/RANGE switches. Your
help will be much appreciated.
Donald?
PE1AHJ
|
Re: Limits of the Port Extension on the Cal screen for calibrating at end of cable
On Sat, 28 May 2022 at 02:22, Tom Lee < tomlee@...> wrote: As far as I am aware, the port extension feature only adds pure phase.
You enter a delay parameter, or a physical length + velocity factor. I
don't recall ever seeing any option to dial in any other parameters
(e.g., loss), but that may be due to my rarely using port extensions,
and then only to shift the reference plane by tiny amounts.
--Tom
--
Prof. Thomas H. Lee
That's true on the 8753, but the PNA-X, and probably some lesser instruments, allow loss to be added too. But no port extension is needed here.
Dave
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Eric Haskell [KC4YOE]
Dr. David Kirkby, Kirkby Microwave Ltd