Re: HP8560E SA Display oddness
Jaap - thank you that's a great find!
Now ....? how did you get to that control? I have the cover off and can't see how to get to that board!
Thanks
Dan
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Re: Hp 8590a spectrum analyzer
I checked the shotky diodes in first mixer and they beep in both directions with the meter in diode check. .262 volts. Not a continuous beep but a short one. Also it spears both ends of the diode are tied together,? I read continuity.? Is that correct ?
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Re: E4418A/4419A vs N1913A/1914A
Perhaps someone dialed in an offset? Press the green preset button to put the instrument back to its normal state and see if that fixes the issue.
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I'm having a issue with a fail code 1310 . Of the 16 leds number 4 and number 12 are lit, but this problem go's away sometimes.? I think the revision is 11,12,86.the service manual is kinda confusion.is this something I can correct entering info or something . Thanks.?
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On 9/5/22 10:59, Yue wrote: Did you check the battery for memory backup ? not sure the 70000 has battery or not but the module should easy to remove for inspection The 70900A/B Local Oscillator module contains a Tadiran TL5104/P battery. It maintains the SRAM contents, including basic configuration info and any stored DLPs. I don't know what's causing the problem with Dave Miller's LO module, but I'm pretty sure it's not the battery. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Did you check the battery for memory backup ? not sure the 70000 has battery or not but the module should easy to remove for inspection?
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I have 2 HP8563E both bought with dead YTO. and both YTO has aged BJT that has insufficient gain to keep the oscillation happen. The new original YTO is not obtainable, so I modified the YTO driver loops and installed two different type YTO (omini / advantek)? and both of them works without problem.
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Also check the power supply. HP YTO (EYO) in 85xx has output level control loop. The loop will over voltage the BJT and finally destroy it if 5V (for output FET) is not present for some extend period.
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I¡¯m also work on the new oscillator board for the EYO. With some modern tiny SMD device the rebuild YTO performance can even better than the old thin film circuits.?
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Re: Hp 8590a spectrum analyzer
On Fri, Sep 2, 2022 at 11:32 AM, Richard Cook wrote:
If you need a terminator I'll send you one .
Thanks! But I have one. Used to install coaxial networking in a distant past!
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Re: Hp 8590a spectrum analyzer
Thanks. Did not know that! 50 ohm I guess?
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Clear screen protector for 16702 touchscreen?
I have my 16702b apart right now.?? I was pondering adding some clear screen protector over the touchscreen.
Large sheets of generic film are available inexpensively.?? I couldn't find any past discussion on this here.? I'm not expecting any issues but thought I'd ask before I ordered some.
Thanks
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Re: Hp 8590a spectrum analyzer
Yes, there should be a termination on the LO output. ?The YIG drives a balanced splitter, with one leg going to the mixer and one to the front panel jack. ?Without the termination, the LO injection will be a bit off and it will skew the displayed amplitude off a bit from expectations. ?Not much, but a bit. ?The LO output is usually used for connecting to a tracking generator. ?
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Re: HP8560E SA Display oddness
8560E - the display characters are not so good Hi Dan and others, Found the problem, at least in my case. It's the DISPLAY CUTOFF adjustment. I did not adjust anything else for the time beeing, just this one. It's on page 64 (PDF page 65) of the 8560E/EC Service Guide from December 1999.  I now have perfect looking characters again. Give it a try Dan. Jaap
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On 9/4/22 18:58, John Lyles wrote: I was using the Hp 436A in the 1980s, and the 438A was a significant improvement, in being able to read forward and reflected power from a dual directional coupler, for example, with built in math abilities. I didn't see the 437A until the 1990s. We bought a few of them, and quickly found that they are not as reliable as their predecessors. I have scrapped more than one dead 437A while the 438A models are still going. One problem in the 437B design is that some parts of its power supply are powered up whenever the instrument is plugged in, but the front panel power switch is "off". I've had several 437Bs, three or four, and I've had one fail because of this. The 4700uF capacitor in the 5V power supply, before the power switch, had dried out. Replacing it solved the problem. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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I was using the Hp 436A in the 1980s, and the 438A was a significant improvement, in being able to read forward and reflected power from a dual directional coupler, for example, with built in math abilities. I didn't see the 437A until the 1990s. We bought a few of them, and quickly found that they are not as reliable as their predecessors. I have scrapped more than one dead 437A while the 438A models are still going.
You can tell about old Hp instruments, if they have LED 7 seg displays and the click style rounded corner buttons, they came before the ones with the rubbery "flubber" square cornered buttons. But their scopes came from a different style again.
These days we buy the N1912A with N1921A sensor, as we are measuring pulsed RF power. I like a Boonton model as well. The specs for the Keysight meters are more detailed where the Boonton has some vague specs that are surprising.?
John Lyles
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E4418A/4419A vs N1913A/1914A
Can anyone explain the major differences between these two series of power meters?
I have a number of E4418A/4419As and they have proven reliable and easy to use, except for one which does not calibrate correctly (after calibrating, the 0dBm reading is off, and this is true even if I use an alternative cal siggen). I haven't figured out how to fix that problem but if anyone knows how to do it...
The N1913A/1914A are newer and more expensive. Any major advantages making the higher price worthwhile?
Thanks!
Jim
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Re: FS: (US) HP 83525A and 83522A RF Plug-ins for 8350A/B Sweep Generator
The HP 83522A has been sold. Thank you for looking. The HP 83525A is still available and ready to ship.
Details are here:?
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Clamp tip for hp current probe
Hello All,
I have an hp 01110-61601 Current Probe that needs the clamp which threads at the tip. Does anyone have any of these they would be willing to part with?
Thanks in advance.
Christopher Tucker
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Re: Which Vector network analysis book to buy - help
On 9/4/22 06:26, Andrew Hakman wrote: Oh god, one of the books on Algorithms you're talking about must be this one
Yup, got that one. While I do like that book, it's a bit too academic, and I'm more on the practical side. My favorite is "Algorithms" by Robert Sedgewick. The book of the class I hated the most, and practically the only class I really cared about that I did poorly in (and the majority of the class did poorly in too). I always loved how the prof started almost every lecture of that class with a huge sigh - he clearly hated teaching that class, and it showed in the performance of the entire class!
I never thought to get a different book, I just took the less than stellar mark and the hit to my GPA and moved on... Being goal-oriented is good. Despite the sales job universities give us since birth, it's actually possible to learn things outside of a school. And it seems like as time progresses, no one knows jack s*it about algorithms or data structures at all. I recently had the (dis)pleasure of interviewing people applying for jobs with "Data Science" focuses - you ask them anything about algorithms or data structures, or complexity / big O notation, and they don't have the first clue about any of it. Then on top of that, EVERYONE now is an expert at Python / C / C++ according to their resume, even if they're a physics major, because at some point they wrote 5 lines of code for some experiment they did one time. Then you ask them "ok, if you know C and C++, what's the fundamental difference between the two?", and once again you get silence back as a response (or the incorrect answer). Yup. And people are just fine with that. China is eating our lunch because they've earned it. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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From the units I have and use about 45-60 minutes is reasonable. I use an external reference to drive them so they are stable very quickly. Paul WB8TSL
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I have a 5245L chassis that I set up for use only as a signal source. I mounted a small incandescent lamp on the front panel, and wired it to the juice that drives the oven heater. It's a sine wave that varies in amplitude (not just an on/off heater), so I can "see" the feedback loop settle in as the temp stabilizes.
Pete
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Dave Smith
Dave McGuire
Anders
Christopher Tucker
saipan59 (Pete)