I have a HP 3456A 50Hz fixed without selectable switch. European model I think.
It is possible to modify without major expense?
Do you need to modify it?
Good question. Yes, I think so.
I don't know exactly but afraid there will be too much heat which may cause
1) fire
and or
2) meter's inside high temperature might affect the meter's accuracy.
and
3) shortens parts life.
No?
all that switch does i tell the integrator to adapt timing to coincide with the power line crossing.
-No?-
read the schematic to be sure.
all that switch does i tell the integrator to adapt timing to coincide with the power line crossing.
So ignore the frequency? Sorry, I am not clear.
-No?-
read the schematic to be sure.
Which part of the schematic should I read? What to make sure?
Thank you
More questions popped up.
I turned on the meter and
it shows ----- instead of numbers.
Pressed the test button and shows fail no 3.
Manual eventually pointed to 8.B.35: 50Hz or 60Hz?
I opened the case and measured the frequency at the crystal. 4.875MHz(50Hz)
So just exchanging with the 5.85MHz(60Hz) crystal will solve the problem?
Any European 3456A users? Could you take a look at the back of your meter if it looks like my meter?
Thank you in advance.
I have a HP 3456A 50Hz fixed without selectable switch. European model I think.
It is possible to modify without major expense?
The 3456A will work on 50 or 60Hz frequency just fine with no overheating. The issue is with the common mode rejection of the 50 or 60Hz, depending upon the power line frequency. This is accomplished by changing a crystal (A30Y1) on the A30 board. The 50Hz crystal is P/N 0410-1225, 4.875 MHz, and the 60Hz crystal is P/N 0410-1226, 5.85 MHz. The HP/Agilent website shows the parts to be obsolete. These are a pretty standard package so I would guess that you could find a replacement somewhere. I have done this many times depending upon where were we installing the equipment. I am not sure why HP just didn't include both crystals in the 3456A, having the unused one in a holding clip, so that you could just change the frequency by installing the correct crystal. Good luck.
Bill
I did the conversion from 60Hz to 50Hz some months ago. The package is HC-50/U, not the common HC-49/U type. The HC-50/U has thicker pins, these are needed to make proper contact with the PCB-mounted holding clip.
I had the crystal custom made. For people located in Europe I can highly recommend these people (no affiliation, just a happy customer):
KRYSTALY, Hradec Kralove, a.s.
Okruzni 1144
500 03 Hradec Kralove
Czech Republic
krystaly@krystaly.cz
Note that my 3456A worked fine with a line frequency of 50Hz, even before I replaced the crystal. Using the correct clock frequency is important only for achieving the specified rejection of noise at the power line frequency.
I believe that the 34401A measures the mains frequency at turn-on and sets its internal timing accordingly. Not sure about the 34410A.
Best regards,
Martin
Interesting that they actually bothered to make a version for 50Hz. We bought an Agilent 34410A recently and I had to write some software for it. Turns out that all the integration timing is based on 60Hz no matter what the power line frequency is.
U902 in the 34410A will sense the frequency for you (judging by the sch). timing is different, where you plug your DMM into the wall.
Anybody know where to buy the crystal in US?
Being made by HP, the popular retailer like Digikey doesn't carry that specific frequency crystal, I think.
Thank you for all the information you provide.
<Edit - added> I want to make sure .... So there is no difference other than the crystal's frequency between 50Hz and 60Hz?
Make sure you check for the correct fuse as well.
Can you understand all the markings on the back of the unit?
Those are pretty odd frequencies and it is not likely that you will find them widely available.
One potential solution is to use a programmable PLL to generate that frequency. A lot more choices available there.
A simpler solution, not likely successful however, is to see if you can find easy multiples of those frequencies and run the signal through a divider.
Nadona, I have a 60Hz 3456A that I would like to convert to 50Hz. Perhaps we could exchange the crystals, so we both get what we need? Send me a PM if you are interested.
Nadona, I have a 60Hz 3456A that I would like to convert to 50Hz. Perhaps we could exchange the crystals, so we both get what we need? Send me a PM if you are interested.
I called them and don't have it. Thank you for the URL, though.
Nadona, I have a 60Hz 3456A that I would like to convert to 50Hz. Perhaps we could exchange the crystals, so we both get what we need? Send me a PM if you are interested.
Great this will be THE solutions.
Hi guys.
I have 1 spare crystal for 3456A/ 50Hz and 3 pcs of 3456A/ 60Hz crystals.
Price: 8EUR / each + shipping cost from Poland.
Maybe someone would find this helpful.
Update:50Hz crystal sold. If someone needs more, please wite an email to
http://www.krystaly.cz/en/Then say them, that you want to order 4,875MHz crystal same as customer "14-03-19 RF Scientific"
It won't cost You a fortune.
Hello Bartlomiej,
i am interested in the 50Hz version.
Please let me know how to order.
Regards,
Martin
I am not sure why HP just didn't include both crystals in the 3456A, having the unused one in a holding clip, so that you could just change the frequency by installing the correct crystal. Good luck.
Bill
I am not sure if continental transfer after initial placement into service was part of expected life cycle. What you're describing is probably only relevant in Japanese market where you have 60Hz in some parts and 50Hz in other parts.
I'm in the need for a 50Hz crystal. I have a 60Hz crystal available. Before i try the link mentioned here, i would like to know if anybody is in for a swap ?
Got one from
http://www.krystaly.cz/en/Actually you don't want the same one as "14-03-19 RF Scientific", this has a package with thin leads (HC-49).
You want HC-50/U with plug type pins. But don't worry, they know what is required for the 3456A
"It won't cost You a fortune." Correct
It fixed my second 3456A, the reading are now stable. It used to be 'noisy' with the wrong crystal present. Happy
Thanks for the information, I wrote an email today to the company, I await their response, Paolo
Ordered two crystal from krystaly. cz for 22 euro included tax and delivery.
Inviato dal mio ONEPLUS A3003 utilizzando Tapatalk
I need to convert a 3456A from 60 to 50Hz and wonder whether someone wants to trade crystals or has a spare 4.875MHz one to sell.