The following files and folders have been uploaded to the Files area of the [email protected] group.
By: Yves Tardif <yves_tardif@...>
Description:
EYO 5086-7934 PCB interface, Electrical schematic
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Re: HP 8447x Series Amplifiers Power Switch
Thanks for your advice. I actually found a couple new switches and ordered them.
By the way, according to a Keysight post (https://edadocs.software.keysight.com/kkbopen/part-number-for-s1-on-the-8477a-588266906.html), the correct switch p/n is 3101-1395 not 3101-1248.
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Whitham D. Reeve
Anchorage, Alaska USA
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Re: HP 8447x Series Amplifiers Power Switch
The switch is an HP 3101-1248 Illuminated AC DPST switch 10.5A 28VDC 125/250VAC. The OAK 53-55480-121 was often used.?
It is a riveted design. Normally I would recommend disassembling a switch to clean and lubricate each part as needed. If you have a lite touch you can drill the rivets and replace them with screws and nuts.
If you choose the less invasive option, use a contact cleaner without lubricants or general electronics cleaner also without lubricants. Either option should not damage the switch or degrade it in anyway. But should is not won't. If you need absolute certainty, disassemble the switch.?
I'm looking for some advice on the 8447x power switches and how to fix them so they operate smoothly.
All these amplifiers use a similar push-button latching power switch and they all seem to have the same problem related to their age - sticky motion when turning on or off.
I know I could try using chemicals but I'm hoping someone has specific experience with these amplifiers and what chemicals to use, how to apply and so on. Also, I'm concerned about the long-term effect of the wrong chemicals.
Thanks
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Whitham D. Reeve
Anchorage, Alaska USA
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N5181A Sig Gen Intermittent Power Switch
Greetings to all readers!
This 6GHz sig gen is functioning properly in every way, except for apparently intermittent operation of the ON-OFF button and associated electronics.? When the button is pressed, sometimes the sig gen starts immediately, whilst on other occasions the amber and green LEDs oscillate "...green-amber-green-amber..." and so-on at about 2 Hz until the machine eventually does start.? The length of time the LEDs spend oscillating in this way is unpredictable, from just a couple of seconds to, say, two minutes.? In the end the sig gen does eventually start, but obviously something is amiss and should be attended to.
I believe that the occurrence of this intermittency is more frequent when the atmospheric humidity on the day is greater than usual and, in that I am located in sub-tropical Brisbane, Australia, this effect is becoming more bothersome at this time of the year.? (I am not having any problems with any of the other soft-touch buttons on the front panel.)
Page 1-57 of the Service Manual mentions these green and amber LEDs, but does not reveal much more.
My intuition is that some dirt has built up in the high impedance electronics associated with the operation of the ON-OFF button and that as soon as the touch of the button is detected, either the 'switch off' sequence is also initiated, or some sort of high impedance short to somewhere is also detected, aborting the switch-on process.
Has anyone had this type of problem before?? Can anyone please suggest a solution?? All replies will be greatly appreciated!? Thanks in anticipation....
--Doug Friend, VK4OE.
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Will an HP8753ES with the built in S-parameter test set slow down calculations compared to using an HP8753ES with opt 011 and the Transmission/Reflection test set (HP85044A)? Our present analyzer is an HP8753ES - 011 --- It does not have a?built-in or attached S parameter test set - it only uses a Transmission/Reflection test set ( HP 85044A).We measure the properties of resonances in our cavity, up to 3 GHz,in?the "thru" mode ( i.e. transmission mode) - We need the peak frequency?and the coupled Q of each resonance.Our unit displays them on the screen when we select the correct display?mode.More importantly, we use a Labview-based program and GPIB commands to?interrogate the Network Analyzer and have the pairs of peak frequency?and Q numbers for each resonance sent to our control computer.?In doing this, speed is very important to us. Our present system can?measure the f and Q of 6 peaks in 3 seconds.
I have a few question relating to what performance we might expect if we?used an HP8753ES with a built-in S-parameter test set:
- Can the peak frequency and Q be accessed via GPIB commands in this S?parameter test-set configuration ?? We have no interest in the S?parameters as such - just the peak frequency and Q .
- If this can be done, will the GPIB commands be different from the ones?we use now with our system ? We don't want to modify the software or have two versions to deal with.
- If all this is a go - will the speed of acquisition be decreased compared?with our present system ?? Will the S-parameter "system" slow things?down in any way ?
Note that the same system using an HP8753C is considerably slower than using an HP8753B which is slower than the HP8753ES.?
Thanks for suggestions or help !
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HP 8447x Series Amplifiers Power Switch
I'm looking for some advice on the 8447x power switches and how to fix them so they operate smoothly.
All these amplifiers use a similar push-button latching power switch and they all seem to have the same problem related to their age - sticky motion when turning on or off.
I know I could try using chemicals but I'm hoping someone has specific experience with these amplifiers and what chemicals to use, how to apply and so on. Also, I'm concerned about the long-term effect of the wrong chemicals.
Thanks
---
Whitham D. Reeve
Anchorage, Alaska USA
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Re: HP 3400A Upgrade PCBs Available
I've had a good look at the differences between the Rev C & D boards and the pdf manual I bought.
Errors I found in the manual;
Parts list,
R601 should be 105k (was 174k) and R604 should be 174k (was 105k).
The circuit diagram, component layout & boards are correct.
Circuit diagram;
C10, missing '+' symbol
R615, decimal point missing from 61.9R
Differences between A6 Rev C and Rev D;
R608 was 22.1k, now 21k
R609 was 22.1k, now 21k
R610 was 2k, now 1.87k
R611 was 2k, now 1.87k
R616 was 1.21k, now 1.02k
R625 was 1M, deleted
R627 was 1k, now 500R
R629 was 100k, deleted
U602 was 1826-0310, now 1826-1381 (LT1012)
I haven't been able to verify all the diodes & capacitors, CR601 is not readable and some tantalum capacitors are facing the wrong way (both on my Rev C and Hal's Rev D).
I've now completed the Rev D design in KiCAD, I used the Rev C board for location measurements, then adjusted the traces for the Rev D design.
Most parts should be obtainable, the 2N4384 transistors seem to be obsolete, but I do have some BCY59X low noise NPN in my spares to try instead, the 1901-0518 Schottky diode I need to find some data for, Molex test point pins have been salvaged from some scrap SA plug-ins.
David
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Re: Adding front panel output to 8340B
Physical space might become a problem (depending where you put the attenuator.? HP has a service note covering rear to front "upgrade" that describes changes to a resistor on the ADC board.? You could implement a relay to switch a resistor in parallel with the existing resistor and retain the calibration. (The rear output has more attenuation due to coax length)
I did not do that because I only use the rear output with my 8510 which does not care about the small change in output.
Cheers!
Bruce
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Re: 1741A - Calibration Frequency at 1.6Hz
The manual states approx 1400Hz, the older 180 series state approx 1kHz, circuits are quite different.
There is the possibility of component drift and capacitors dropping in value around IC U4B on A3.
David
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1741A - Calibration Frequency at 1.6Hz
Greetings, first post.....
I have a 1741A and a couple frequency counters.? Just futzing around while reading the manuals I decide to plug the 1741A calibration posts to the counter. The documented frequency of the 1741A is 1400 Hz. The counters tell me another story, both agreeing to something? like 1611.x Hz, each using the internal clocks as opposed to a shared external time base. On their internal tests the counters are spot-on.
There is a volt peak-to-peak adjustment in the 1741A but not a frequency adjustment, even then a +-14% offset just does not make sense. With a slow DMM the output is measured at 0.495v, which seems sort of normal since it is a 50% duty cycle square wave. So, I am thinking that there is something going on inside the scope, i.e. some component(s) on it's way out.
Has anyone seen this in a 174x or similar scope? Is this frequency used internally for measurement results and if so what? Any suggestions would be welcome.
Cheers, Bert
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Re: 4195A restoration adventure*
Hi Ruben, ? ??????????????? I would be tempted to look for octal D-flipflop, octal buffer tri-sate first. ? On the image I put the curve corresponding to that of the Spectrum analyzer (image Spectrum), it is certain that the PLL integrator will create a delay, and the shape will be a more or less symmetrical sawtooth depending on the charge pump. So, the waveform I drew will tend to shift to the right if there is more delay in the PLL loop. ? The image on the right would be output J12 of the SUM LOOP PLL. ? Good luck, without an electrical schematic, it won't be easy. ? ? 
? ? Yves, you got point
That MSB locked on high level makes all sense, mate. I will check that. Must indentify all IC in A18 to get an idea of how it works, separated by sections acording to rude block diagram I have. Sure there's logic circuitry in charge of control. It will be hard without schematics...
Thanks again, Yves, you excel is a true key to troubleshoot ;)
Regards,
Ruben
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Re: YTO 5086-7080, label interpretation?
Aha, I see. Thank you for this information.
I plan to check if it still works sometime this week[end]
Wilko
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Re: 4195A restoration adventure*
sorry for the error, sentence to be corrected::? ¡°and this problem would NOT affect other frequencies higher than 266.66... MHz since the MSB is already at 1 normally.¡± ? ? ? Hi, ? Just a quick comment that may have nothing to do with your problem. ? You say "The output signal from A18 (rear LOCAL BNC named J2) has to vary between 233.33 and 413.33 MHz. But it starts at 266.x MHz." ? If you look at the image below, it is perhaps just a coincidence, but the fact that the MSB would always be fixed at 1 for example (some defective register), the start freq would then be 266.66... instead of 233.33 ... and this problem will only affect other frequencies higher than 266.66... MHz since the MSB is already at 1 normally. So, in the faulty location, there would be no detection and probably PLL unlock. ? 
? Yves ? ? ? I have retraced my steps to check the signals passing from the upper unit to the lower unit.
The LOCAL signal, responsible for being the LO in the lower unit for both the Sources and Inputs, has improved its behavior. But he still has a problem. This signal is the product of mixing of a signal from A10 that varies between 5.83 and 10.33 MHz and is sweeped three times to complete the scan seen on the CRT. That signal has the appropriate frequency, although I cannot be sure of the amplitude because I don't have extenders for this boards and probing the signal is difficult and erratic. The output signal from A18 (rear LOCAL BNC named J2) has to vary between 233.33 and 413.33 MHz. But it starts at 266.x MHz. Hence the attenuation observed three times during the scan on the CRT.
I though in amplify the A10 signal with an external amplifier in case it's attenuation isn't enought to drive the first mixer in A18. But the sweep is too flat to be a problem with mixer input, imo
In the excerpt added you can see the procedure suggested to isolate the fault and then toss the entire board :D 1990 was the year to reject component level service, that's clear for me now...
Regards,
Ruben
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Re: 4195A restoration adventure*
Hi, ? Just a quick comment that may have nothing to do with your problem. ? You say "The output signal from A18 (rear LOCAL BNC named J2) has to vary between 233.33 and 413.33 MHz. But it starts at 266.x MHz." ? If you look at the image below, it is perhaps just a coincidence, but the fact that the MSB would always be fixed at 1 for example (some defective register), the start freq would then be 266.66... instead of 233.33 ... and this problem will only affect other frequencies higher than 266.66... MHz since the MSB is already at 1 normally. So, in the faulty location, there would be no detection and probably PLL unlock. ? 
? Yves ? ? ? I have retraced my steps to check the signals passing from the upper unit to the lower unit.
The LOCAL signal, responsible for being the LO in the lower unit for both the Sources and Inputs, has improved its behavior. But he still has a problem. This signal is the product of mixing of a signal from A10 that varies between 5.83 and 10.33 MHz and is sweeped three times to complete the scan seen on the CRT. That signal has the appropriate frequency, although I cannot be sure of the amplitude because I don't have extenders for this boards and probing the signal is difficult and erratic. The output signal from A18 (rear LOCAL BNC named J2) has to vary between 233.33 and 413.33 MHz. But it starts at 266.x MHz. Hence the attenuation observed three times during the scan on the CRT.
I though in amplify the A10 signal with an external amplifier in case it's attenuation isn't enought to drive the first mixer in A18. But the sweep is too flat to be a problem with mixer input, imo
In the excerpt added you can see the procedure suggested to isolate the fault and then toss the entire board :D 1990 was the year to reject component level service, that's clear for me now...
Regards,
Ruben
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Re: Adding front panel output to 8340B
I have an 11801/SD-24 so I should be able to make a matched pair such that the instrument doesn't care.
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8341B key cap pn 5041-2731
All,
As part of a restoration project I¡¯m seeking a key cap, HP pn 5041-2731. It is labeled ALT and is used on both the 8341B and the 8340B. I have neither the skills nor the equipment to 3D print one and would prefer an original.
Thanks,
Steve
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Re: YTO 5086-7080, label interpretation?
Don't worry about those numbers. There's an oscillator and an amplifier stage. The "I" is the desired emitter current, determined by the "R" which are selected to optimize the stage performance for that particular YTO and its transistors. The "R" values are the actual resistors on the support board - you can read them out, and you could estimate the currents too, for diagnosis of problems, but you shouldn't need to. They have nothing to do with the coil currents.
Ed
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Re: Looking for Dual Banana Plug test cables
True.? I understand there is Star Quad cable for even better balance, at least at audio frequencies.? Never used it myself, though.? Good luck!? ? ? ?Jim?
Sent from my T-Mobile 4G LTE Device
toggle quoted message
Show quoted text
-------- Original message -------- From: Tom Haynes <tomhaynes.net@...> Date: 11/26/23 12:24 AM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Looking for Dual Banana Plug test cables
That would produce a shielded dual banana plug cable but it wouldn't be balanced.
A balanced shielded cable has 2 twisted signal wires and a shield wire or outer braid. Or get a Pomona Electronics female BNC to dual banana plug adapter and use a BNC? cable.? ? ? ? Jim Ford
Sent from my T-Mobile 4G LTE Device
-------- Original message -------- Date: 11/25/23 10:29 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Looking for Dual Banana Plug test cables
Pamona makes what you are looking for.
Available in digikey or mouser for $55 for most lengths.
On Sun, Nov 26, 2023, 2:45?PM Bruce < bruce@...> wrote: I am looking for up to 3 dual banana plug BALANCED - SHIELDED test cables - these cables would have two banana plugs cast in plastic on each end and a third connection (shield) on one end.? I would purchase or trade for them.? Please let me know if anyone has any they are willing to part with.
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YTO 5086-7080, label interpretation?
On a recent hamfest I acquired a HP YTO 5086-7080. I want to check it out to see if it still works. Google told me this YTO is used in a HP 8558B SA. Also delivered me some manuals for that SA model.
Now the question: the YTO is labeled?
IA = 71 mA
RA = 68.1 ¦¸
IO = 32.2 mA
RO = 196 ¦¸
What are these values referring to? I measured both the main coil and the FM coil and these are ~47.4 ¦¸ and ~1.2 ¦¸ respectively. I used the info from the 8558B service manual to determine which pin is which on the YTO.
The service manual also told me that the current through the main coil must be in the range of approx 50 - 8 mA. For the FM coil it indicates -25 mA ... +25 mA for " <= 1 MHz / division.
So... I am now thoroughly confused ? Who can enlighten me please?
Wilko
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HP5340A Repair Suspect A22 U9 Schmitt trigger, type 5086-709
Hi Folks, My HP5340A has stopped working at the input to A22 first 2 digits input selector. The U9 Schmitt trigger in a gold can seems to be loading it's input. It is driven by a EECL logic switch which has no output, so I've swapped it with U3 which is an identical switch with the same result, hence my suspicion that is is the next IC that is loading the output. I then tried to simulate an EECL input to U23 output. I think I have damaged this.
My question is are these chips available at a realistic price anywhere or have I now got an HP5340A shelf queen?
Any advice would be gratefully received. Thanks. Chris Hayes. Norfolk, UK.
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WReeve
DougF VK4OE
factory
Chris Hayes