Re: HP 5086-7842 Attenuator - max input power
You can find the pin outs, schematics, specs, for the 33320 through 33323 series attenuators in the older HP, Agilent Microwave Accessories catalogs. You may find some of them posted on this forum site. The PN seams familiar to me and may be the attenuator used in the 8566B. Check the manual for the 8566B for this PN. If this is the case then it is a 70dB attenuator (10, 20, 20, 20 dB sections), 0-22GHz, 1W max input, atten. drive should be +15VDC (think current). There were several different part nos. used in the 8566 spectrum analyzers, but all are equivalent. At one time you could look up the part no. on the HPAK website, replaceable parts, and find out where this part was used. I don't know if you can still do this. This is definitely an HP 33321 series attenuator.
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Re: HP 8341B Firmware Questions
Hi, From what I have read a v7.xx of 8510C requires 1992 version of 8341B. I am therefore interested in hearing your answer. I have a 8510C with firmware v7.10 Mar 30, 1995 and a 8341B with firmware 11 May 88. They work fine together with a 8515A. Also remote control with GPIB works fine with various adapters. Best regards, Job
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Re: 8566B - Low signal on 2-22 GHz band
Re...
On 09/07/2024 21:01, [email protected]
wrote:
During this time I
found R106 was burned on my original A6A12. Concerned this could
have been caused by a damaged coil in the YTX, I decided the next
logical step was replacing the YTX with one from the donor unit.
Success! I was able to achieve a full amplitude signal across all
tested frequencies.
I wonder if a shorted turn in the YTX device could cause that?
Was there any noticeably different behaviour at faster sweep speeds
than slower?
Regards to All.
Dave B.
--
Created on and sent from a Unix like PC running and using free and open source software:
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Re: HP8341B not being detected over GPIB with GPIB-USB-HS and NI MAX
Hi.
Glad to help.
IO-Trace is "The" tool to have, for any GPIB/HPIB weirdness you might come across using NI's tools.? (I have no idea if the Agilent/Keysight equivalent systems have a similar tool.)
It works for all traffic going out/in over the GPIB, not only VISA calls, but "old school" board level calls too.
(It might even log calls to other interfaces, if managed by the NI drivers, I'm not sure.)
NI has a good description of how to use it here:-
There are lots of options, many will lead to "HUGE" files being created (they compress very well with the usual file compression tools etc) but they will contain all the info needed to see what's happening.
Re the faulty HPIB board.
"If" your HP machine is one of the products that uses the famous HP "Nanoprocessor" on the HPIB board, check it's local DC power rails.
As usual, they should be clean and stable.? Especially the "bias" pin (38) on the processor, that should have the voltage on (wrt to local 0V on Pin 17) it that is marked on top of the 'processor chip itself.? Typically between -2 and -5V
Pin 39 is the main +5V, and Pin 40 "Vgg" could be +9 or +12V (+- 5%)? Depending on version of Nanoprocessor.
1820-1692 (NP-A) uses +12V?? 1820-1691 (NP-B) uses +9V
(According to the documentation I have dated 11/10/1975.)
It uses an external (on the same board) ROM for the code it runs.
As I recently found on a little HP 3438A DMM I have.
The GPIB board's dedicated PSU rail (it's main +5V!) was bad.? A failed (open) rectifier diode, and the resulting bad electrolytic cap in that case, no doubt due to the excess ripple current, was causing 100% ripple on the +5V!? (It was more like a 50Hz Square Wave!)? Replacing the diode and the cap' (plus another similar cap for the +12V rail, that had not quite failed) restored full operation!
(The DMM circuitry is fully floating with it's own PSU rails, communicating with the HPIB board via opto isolators.)
What I was initially seeing, was partial GPIB activity (using an Arduino or PIC based USB-GPIB device I have, I do not use Windows) it could be addressed, showing the indicator on the front panel, but fail to complete any handshake.? Even in the data streaming "Talk only" mode, it would not do anything!
Quite how the Nanoprocessor survived that abuse for presumably an extended time, I do not know.? HP obviously designed and fabricated those things very well!
(If only a lot of modern stuff was just as forgiving!)
Hope something helps.? The HP8341B is a very nice instrument.? I'm green with envy!? :-)
Regards.
Dave G8KBV.
--
Created on and sent from a Unix like PC running and using free and open source software:
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Re: HP 5086-7842 Attenuator - max input power
Power handling.
All thase attenuators use tha same atteunuator "cards". Power rating is 1 W average, 100 W peak with maximum pulse width of 10 microseconds.
Note that 10us is much shorter than a quick press of the PTT. These are NOT power attenuators.
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Re: HP 5086-7842 Attenuator - max input power
Forgot to say,
Common coil voltage options are 24V, 15V and 5V .? Resistances are 190, around 100 and 17 Ohms respectively. Also if there is a ribbon cable connection the colurs are consistent to function whatever the connector.
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Well, it took a little longer to get results, but here it goes: After constructing an adapter board for the FM16W08 (the readily available ones from China do not fit the socket) the patient seems fully cured: all things work as expected, and the settings are remembered. "Look ma! No batteries!" ;)  For those interested: I have 1 fully assembled FRAM adapter and three bare PCBs left over for sale...
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Re: 8341B with 8510C v6.xx. Is it possible?
I don't think the uprade is a problem.? AFIK anything working with V6 will work with V7, but the reverse is not true.
Do you have a complete 8510C system now?
Cheers!
Bruce
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Re: HP 8566B - Can my high voltage transformer be faulty?
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Re: HP 5086-7842 Attenuator - max input power
On Tue, Jul 9, 2024 at 12:41 PM, <fpgadaemon@...> wrote:
5086-7842
That part is replaced by the 33321YT so it probably has the same pin-out as the 33321Sx range. Voltage is another question may be 5V or 15V It may or may not have auxilary contacts to disconnect the coil after it has latched. If not you must puse the signal. I use the attached circuit to test these. It uses a pair of BCD thumbwheel switches to select all options. Set required attenuation and press the momentary switch. 
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Re: HP 8566B - Can my high voltage transformer be faulty?
Common fail in old TV receivers. Shorted main winding usually damages transistor driver.
Always diffucult to diagnose.
Try, with power off to excite the main winding with RF oscillator. May be several KHz frequency. Does it resonate? See a voltage waveform for the driver, it may help indicate the frequency.
In TV it was 15,750 KHz.
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Re: HP 3754A RF Switch Utility?
Thanks Bill! Thats what I needed to know! Jeff
In a message dated 7/9/2024 2:50:40 PM Eastern Standard Time, bill.lauchlan171@... writes:
?
3754A is for Telco FDM baseband test access in a central office. 3 level higherarchy. Controlled? by hp3755a? via twisted pair or coax. Probably no use to you.
Bill Lauchlan
> On Jul 9, 2024, at 1:43 PM, Peter Gottlieb via groups.io <hpnpilot@...> wrote:
>
> Not entirely sure.? There must have been some ATE need they designed this to satisfy at the time.
>
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>> On 7/9/2024 1:38 PM, Jeff Kruth via groups.io wrote:
>> I have one of these in the pile. I have read the manual, and apart from the fact you can stack these 10 channel witches so you can access 1000 RF signals. what good are these. Only good to 25 MHz. Any thoughts, anyone? Need space here. Jeff Kruth
>
>
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HP 5086-7842 Attenuator - max input power
Hi, I've recently purchased a 5086-7842 attenuator from a radio amateur, with the intent of making a stand alone adjustable attenuator. However, I am unable to find a datasheet for this attenuator, and am curious about the following:
1) Whether the DIP pinout might be the same as attenuators of a similar form factor, such as the 33323K?
2) What the maximum input power might be.
Any advice, or suggestion of resources to check, would be appreciated. I've tried googling, but only come across other units for sale on Ebay.
Regards, John.
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Re: HP 3754A RF Switch Utility?
3754A is for Telco FDM baseband test access in a central office. 3 level higherarchy. Controlled by hp3755a via twisted pair or coax. Probably no use to you.
Bill Lauchlan
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On Jul 9, 2024, at 1:43 PM, Peter Gottlieb via groups.io <hpnpilot@...> wrote:
?Not entirely sure. There must have been some ATE need they designed this to satisfy at the time.
On 7/9/2024 1:38 PM, Jeff Kruth via groups.io wrote:
I have one of these in the pile. I have read the manual, and apart from the fact you can stack these 10 channel witches so you can access 1000 RF signals. what good are these. Only good to 25 MHz. Any thoughts, anyone? Need space here. Jeff Kruth
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Re: 8566B - Low signal on 2-22 GHz band
Hello, All,?
I am happy to report a successful repair! By a stroke of pure luck, I found a parts 8566B locally for a very attractive price. It was missing the entire A11 section, and the 2nd converter, but was otherwise in-tact.?
I wound up replacing the A6A12 YTX driver card with one from the donor unit. This was a partial success, as it would finally display a meaningful signal, albeit 30 dB low and not 90 dB low. By performing a factory reset of the YTX current (SHIFT, PRESEL PEAK) the error improved to -20 dB, and by adjusting the DAC control (SHIFT, GHz) I was able to get a full amplitude signal, although it was non-linear as I changed the input frequency.?
Ok, so on the right path, but something is still off.?
During this time I found R106 was burned on my original A6A12. Concerned this could have been caused by a damaged coil in the YTX, I decided the next logical step was replacing the YTX with one from the donor unit. Success! I was able to achieve a full amplitude signal across all tested frequencies.?
TLDR for those reading this from the future, looking for help with their 8566B. The conclusion is a failed coil in the YTX that overloaded the A6A12 driver card. Replacing the YTX and A6A12 solved the issue. R106 could likely be replaced, but as I had a spare card, and one that was tuned to the YTX, I elected not to repair the original.?
Thank you everyone for all of your help and advice!?
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Re: HP 3754A RF Switch Utility?
Not entirely sure.? There must have been some ATE need they designed this to satisfy at the time.
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Show quoted text
On 7/9/2024 1:38 PM, Jeff Kruth via groups.io wrote: I have one of these in the pile. I have read the manual, and apart from the fact you can stack these 10 channel witches so you can access 1000 RF signals. what good are these. Only good to 25 MHz. Any thoughts, anyone? Need space here. Jeff Kruth
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HP 3754A RF Switch Utility?
I have one of these in the pile. I have read the manual, and apart from the fact you can stack these 10 channel witches so you can access 1000 RF signals. what good are these. Only good to 25 MHz. Any thoughts, anyone? Need space here. Jeff Kruth
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Re: HP EPM 4418A cracked plastic
For the rear bezel, go on eBay for decent reproduction parts. I do that quite a bit since many come through with broken rear bezels.
For issues on the front bezel, I have used service cement (if you can still obtain it). I have found CA accelerator to soften the abs and use it very sparingly.
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Re: What group deals what resistance standards ???
hi Bruce,
I realize you are asking for "Repair" instead of "Calibration", ... but the Cal aspect will come shortly thereafter:
? So, you might also reach out to the two North American?? National Measurement Standards?? groups, to see if a technician there *might* have any technical information, suggestions, tips,? or repair/refurbishment info on your particular Resistance Standard.
( ... Or if in the EU, then try NPL, PTB, BIPM ).?
These orgs have publications freely available on the Web concerning all types of Calibration measurements.
Either or both of? NIST (US)
? or NRC (MSS?? - was INMS ) in Canada:
rick
(electron/photon & Time-Volt? nut)
**
a)? NIST:
?Refs (? or? possible bedtime reading ) :
b)? NRC Canada ( MSS or was called INMS ) :
{ typically faster turn around Calibration times, at typically a cheaper price }
Refs:
Also,
?? for measurement guidelines, have a peek at:
and? its derivative:
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Re: HP8341B not being detected over GPIB with GPIB-USB-HS and NI MAX
Apologies if this is incorrect, but if the GPIB has selector switches for address and talk only/listener functions, then it might be worth exercising them as they have been known to go hi-res and cause issues. ? Usually operating them a few times and possibly cleaning them usually helps a lot ¨C just can¡¯t remember if your instrument has those or if it is done in s/w. Regards Nigel ?
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From: [email protected] <[email protected]> On Behalf Of saevar via groups.io
Sent: Tuesday, July 9, 2024 11:12 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP8341B not being detected over GPIB with GPIB-USB-HS and NI MAX? Dave, thanks for the advise on using the IO-trace, it helped me see what was going on on the bus.
A little update, it turns out that there is a problem with GPIB on my A60 board which was causing this. It, as far as I can see, works otherwise. If someone has a spare that they are willing to sell for a fair price please contact me offline, its part no. is 08340-60299.
Regards
Saevar
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