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Re: HP 8566A large amplitude error in 2-22GHz range
An additional "expiriment" to try instead of REACLL 8, is to do CENTER FREQ = 100MHz with the calibrator conneced to the input. Then press FREQUENCY SPAN and use the down arrows to slowly narrow the frequency span. Are you able to see the calibrator signal at 100MHz and is it at about -10dBM, Can you use the front panel CAL ADJ to make it at about -10 dBm?
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Now start reducing the scan width (down arrow) assuming you cn see the cal signal, does it stay centered, if not, at which combination for FREQUENCY SPAN, RESOLUTION BW, VIDEO BW, does is slide off the display. If it slides off the display, does it do so slowly (closer to an edge with each down arrow press), or does it appear to jump off the dispaly (move from near the center ot of the screen). Good luck Quoting huszaghmatt@...: John, thanks for the info! |
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Re: HP 8566A large amplitude error in 2-22GHz range
On Tue, Dec 8, 2020 at 03:47 AM, amirb wrote:
Assuming the LO level driving the harmonic mixer is OK (the correct level must be in the service manual)A bit of a wild guess, since I don't know these SA's very well, but ISTR there's an el. cap. on the YIG drive module itself that was bad (leaky or low cap.) in one story I read, causing hunting and phase noise in the YIG. Could be a completely different SA model though. Raymond |
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Re: Agilent 54831M
Bostonman
I have an old USB stick with Slacko (Puppy Linux) on it. I thought using this to boot the mother board would be more reliable than any Windows based CD. Unfortunately it didn't seem to boot as I got the following message (see attached).
To confirm the thumb drive was good and Linux still loaded, I tried it on my dummy PC and got a 'press any key to reboot' message. Questioning the thumb drive,I tried it on a known good working laptop, and it loaded Slacko perfectly fine. Assuming the scope motherboard is capable of booting an OS, maybe it dislikes booting from the USB, or it can't handle newer operating systems. Do you have a suggestion (and a link) for an ideal basic OS that I can burn to a CD and try letting the motherboard load it? |
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Re: HP 8566A large amplitude error in 2-22GHz range
Think I missed an e-mailor two.
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Did you do recall 8 and what was the result? Did you measure the power at the calibrator output? Also, I agree with John 100% - DO NOT try to adjust anything until you have an idea as to the basic failure. It is too early to determine if it is adjustment or part failure, but you can ake yourself feel better about the YIG by watching the power output during a very slow scan from 2.3 - 6.1GHz The other thing to remember is that parts for these analyzers are available and fairly inexpensive. One last question that i forgot to ask - How many cards are there in the enclosure with the CPU - it will be either 3 or 5 as I remembr. Cheers! Quoting huszaghmatt@...: John, thanks for the info! |
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Re: HP 8566A large amplitude error in 2-22GHz range
I second John's comments. As I have been saying all along, first of all you should FORGET the amplitude issue and solve the YTO unlock
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the reason that CAL does not run is that the instrument switches to narrow spans during cal where the LO has to be locked for spans wider than some threshold (not sure about this particular instrument but typically the threshold should be a few MHz) the YTO? is not swept in Locked mode They just lock it at the beginning of sweep and then sweep the main coil as a free run oscillator for spans narrower than the threshold the LO must be locked all the time and when it is not, then you miss the signal completely because the drift in your LO is larger than your span and the signal appears somewhere outside of your span, as soon as you make it a large span you suddenly see the signal (sort of) in the right place. Cal needs very small spans, so LO lock is crucial otherwise siganl is lost and Cal stops since your LO amplitude was flat strong, your YTO is good and unlock issue is most likely in the YTO drive circuit (can very well be bad caps) or it could be in the Reference section. As I mentioned before, a simple test is to make sure your Cal out signals is rock solid on another SA that most likely rules out any problem in reference section.? now, after the LO is locked, your amplitude problem can be addressed and as John said and I said from the beginning I dont think this is a calibration issue. Assuning the LO level driving the harmonic mixer is OK (the correct level must be in the service manual) then I think the YTF is not tuned correctly, either the YTF itself is bad which I dont think it's the case here or again its driving circuit is bad. In any case, as John mentioned, you should never even attempt calibration on a faulty unit unless all circuit defects are fixed or ruled out. otherwise it will just mess up the good calibration that your unit might already have On Mon, Dec 7, 2020 at 09:16 PM, John Miles wrote:
?On Mon, Dec 7, 2020 at 09:16 PM, John Miles wrote: circuitry that determines the stepped baseline level for the noise |
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Re: HP 8566A large amplitude error in 2-22GHz range
John, thanks for the info!
The signal is still there actually. I can see it if I connect that output to an oscilloscope. It just doesn't show up when I do recall 8, which I guessed might be another symptom of the YTO unlock issue. But, take my guesses with a grain of salt since they're not very well informed at this point... Would you mind clarifying why you believe this is a component failure, rather than just a tuning issue? I very much appreciate your concern that if I tune these and that turns out not to be the issue that may end up being a lot of work in the wrong direction. In any event, it seems like checking the caps is a harmless place to start. |
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Re: HP 8566A large amplitude error in 2-22GHz range
¿ªÔÆÌåÓýThe complete loss of signal might be a blessing in disguise, if it makes it easier for you to narrow down the problem.? Contrary to what you've been hearing, that's not an adjustment or calibration issue, but an actual component failure, possibly more than one.? The trick, as usual, is finding it.? With these particular instruments, step #1 is to get an ESR meter and shotgun-test every axial electrolytic you can find.? That may not identify *the* problem, but it can save you from additional hair-pulling later. ? One possible clue: the circuitry that determines the stepped baseline level for the noise floor in the 2-22 GHz band is mostly, but not entirely, separate from the circuitry that drives the YTO.? I'd look at the areas of the block diagram that are common to both, such as the sweep ramp voltage generator.? ?Do this after a careful check of the power supply voltages, of course. ? Whatever you do, don't attempt to solve this issue by 'calibrating' the trimpots for baseline leveling.? They are probably fine, and if you tweak them unnecessarily, it can take hours of work to bring them back into proper adjustment. ? I don't know that I would hold the seller's feet to the fire on this one, because these things are old enough that any number of things are likely to break, especially after long periods of inactivity. ?For many sellers, "Perfect working order" means "Showed something on the screen and didn't trip the circuit breaker, at least not right away."? That's eBay for you.? :(? A partial refund might be a fair request, depending on the language in the original listing, but that's about all that can be hoped for as far as compensation is concerned. ? -- john, KE5FX ? ? From: [email protected] [mailto:[email protected]] On Behalf Of huszaghmatt@...
Sent: Monday, December 07, 2020 3:25 PM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] HP 8566A large amplitude error in 2-22GHz range ?
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Re: HP Catalog : Sold
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On Dec 7, 2020, at 6:52 PM, Mike Feher <n4fs@...> wrote:
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Re: HP Catalog : Sold
¿ªÔÆÌåÓýRick ¨C Simple mistakes happen all the time and we have all been on the receiving end one time or another. I would not lose any sleep over it. I sold an expensive microwave horn on eBay last year and I still cannot find it. 73 ¨C Mike ? Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 ? From: [email protected] <[email protected]> On Behalf Of Rick - WA6NDR
Sent: Monday, December 7, 2020 7:16 PM To: [email protected] Subject: Re: [HP-Agilent-Keysight-equipment] HP Catalog : Sold ? David: You sent me an email that said "Sorry but the catalog was taken and paid for before I saw your reply."? So I am losing out because of your mistake.? Please consider refunding the person that replied after me and giving the catalog to the first reply (me). |
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Re: HP 8592b
Thank you for your answer Bob.
Let me rewrite my problem since the beginning: - There was not any problem about a year ago. - I got error 0030 1 week ago - Replaced the battery - Screen was flickering after battery replacement, and I fixed that with calibration - I calibrated FREQ and AMPTD without any problem - I cannot calibrate YIG since I got "LOST COMB SIGNAL" |
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Re: HP 8566A large amplitude error in 2-22GHz range
One other thing you could try is the frequency diagnostic test - not sure the A version supports this but try the following: This worked yesterday, but now I'm no longer seeing a signal... |
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Re: HP 8566A large amplitude error in 2-22GHz range
Image was fine - shown frequency response needs adjustment. Try manually sweeping the 2.3-6.1 GHZ range and see if you can get a feel for where the YTO is locked and where it is not locked. Also note whether any other error messages show up in the RH middle of the CRT (where the YTO message appear).
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One other thing you could try is the frequency diagnostic test - not sure the A version supports this but try the following: Connect the calibrator to the input; press GREEN KEY; RECALL 8; and adjust for -10db marker. Next Press GREEN KEY; BLUE KEY; FREQUENCY SPAN(W) (with calibrator still connected) - it will run a test for some time - when (if) that test completes - Press BLUE KEY then LINE(w); BLANK A TRACE;ENTRY OFF (above the rotary dial) - you should get a couple colums of numbers - send us a picture. All this is documented in the first few pages of the service manual HAVE FUN !!! Quoting huszaghmatt@...: Bruce, |
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Re: HP 8566A large amplitude error in 2-22GHz range
Put a power meter on the LO output and sweep band 1 (slowly) - if the LO remains relatively level, the YIG is OK (which is what I'd suspect).Thanks, I'll try that. The only problem is that you will need access to a spectrum analyzer to do a competent YTO adjustment. You could try it with a frequency counter and a power meter, but it would be BRUTAL. The range you will need to cover is 2.3-6.1GHz which is band #1The only other SA I've got is really cheap (although I believe it does cover those frequencies). In any event I'll give it a shot. Do you have the use and service manuals? If not, you should download them and start reading. I do, and that is my plan. Thank you for all the terrific advice! |
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Re: HP 8566A large amplitude error in 2-22GHz range
OK - clearly in need of frequency response adjustment but DON'T TRY that at this point. Is the YTO unlocked during the entire sweep or only at some points. You could try to find sweep ranges where the YTO stays locked, and ranges where it unlocks. Based on what I've seen so far, there may not be significant problems. Put a power meter on the LO output and sweep band 1 (slowly) - if the LO remains relatively level, the YIG is OK (which is what I'd suspect).
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The only problem is that you will need access to a spectrum analyzer to do a competent YTO adjustment. You could try it with a frequency counter and a power meter, but it would be BRUTAL. The range you will need to cover is 2.3-6.1GHz which is band #1 Cheers! Do you have the use and service manuals? If not, you should download them and start reading. Quoting huszaghmatt@...: Bruce, here's the image using the 150s 8566A sweep. |
Dave McGuire
Rick - WA6NDR