Author Topic: HP 3458A VFDs  (Read 455 times)

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Offline perdrix

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HP 3458A VFDs
« on: October 12, 2019, 02:58:38 pm »
Looks like someone in China has found a case of the VFDs used in the 3458A!  eBay item number 113920233966

Not cheap but ...

David
 

Offline Bill158

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Re: HP 3458A VFDs
« Reply #1 on: October 13, 2019, 05:06:30 pm »
There are several questions to be concerned about on these VFD displays.
1. Are these the "old" pin spacing?
2. Who manufactured these VFD displays?
3. Are they original H/A/K parts or knock offs?
I purchased a 3458A VFD display 2090-0217 a few years ago when they were being listed as available for sale on the HP/Agilent/Keysight website, without having to buy the entire Display PCB assembly.  It was around US$80 as I remember.  After I had removed the old VFD from my display PCB, which was a job in itself (60 pins), I discovered that the pin spacing from top to bottom of the new display was 1.6 inches while the PCB and the old display was 1.4 inches.  It took hours and hours to carefully bend and then insert 60 pins into the old board.  After I was done the display worked correctly as expected.  But apparently H/A/K had redesigned the Display PCB to accommodate the new pin spacing of 1.6 inches.  BUT the part number was the same.  So my question on these displays is pin spacing.
A friend found a source of 3458A VFDs a year ago or so.  The best as I can determine these come from "TAOBAO" at https://item.taobao.com/item.htm?spm=a230r.1.14.46.14590d6eLuFDRV&id=538154307229&ns=1&abbucket=6#detail.  The price is ¥750 which seems to convert to around US$105.  So with handling and shipping the final price was around US$150 each.  He ordered 1 initially to try out and then ordered 3 more total for himself,  another friend and me.  I still have mine because I don't have a need to install right now, just hedging against the future.  The originals from H/A/K are made by NORITAKE.  These from TAOBAO are NOT (obviously a Chinese knock off), but work just fine and are brighter than the originals.  Also  there are physical size problems, as my other friend who did not order these, found out.  There was a shield that was touching some of the pins which he didn't see when he did the installation, but with a little bending fixed the issue.  Also the VFD from TAOBAO has the 1.6 inch spacing which means I face another 1 day task of changing once I have to do this job.  Also from what I can see in the various listings on ebay most of these seem to be the knock offs.  The "give away" is that the knock offs have a small "circular" something in the lower right corner of the display which appears to be a "getter" as we used to call it in the old vacuum tube days.  The only listing that I see that looks like NORATAKE is 293250709061 but it is very hard to tell from the photo.
Bill
 

Offline SilverSolder

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Re: HP 3458A VFDs
« Reply #2 on: October 15, 2019, 07:35:35 pm »

[...] apparently H/A/K had redesigned the Display PCB to accommodate the new pin spacing of 1.6 inches.  BUT the part number was the same.  [...]

Version control... gotta love it!

Maybe the board had a different rev letter even if the part number stayed the same?
 


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