[time-nuts] Looking for a HP-58503 display

Bob Bownes bownes at gmail.com
Tue May 9 16:19:08 EDT 2017

On a (slightly) related note, I have a Futaba DRO on my milling machine.
The VFD display, as you mention, had grown very dark from being left on
constantly. As it was a simple display with 6 7 segment digits, conversion
to LED was actually pretty easy. It took about 4 hours one Sunday
afternoon. There are a couple of indicators on the display as well, but
they are not used on my model, however, I could have replaced them with a
single LED and silhouette easily enough.

The process was pull the display, pull the display drivers, replace the
drivers with some header plugs that pass input to output, send the output
to a display board where they go to a pair of 74AHCxxx buffers (inverting
iirc), which then directly drive a pair of three digit common cathode LED


On Tue, May 9, 2017 at 3:42 PM, Gregory Beat <w9gb at icloud.com> wrote:

> Mark -
> Option 001 for the HP-5803B GPSDO
> featured a 12-character (alphanumeric) Vacuum Fluorescent Display (VFD).
> It appears to have been a custom VFD for HP / Agilent (Colons used in time
> display).
> http://www.leapsecond.com/museum/hp58503a/097-58503-13-iss-1.pdf
> Noritake Itron Corp. (Ise Electronics Corp.) of Japan invented the VFD
> technology in 1967.  Noritake, Newhaven, Futaba, Samsung, and a Chinese
> mfg. are the 5 major mfg.
> Three of these companies have their North American HQ offices here in
> Chicago area.
> Futaba in Schaumburg
> http://www.futaba.co.jp/en/display/vfd/lineup.html
> Noritake Itron Company in Arlington Heights
> https://www.noritake-elec.com/
> Newhaven Display in Elgin
> Company is more of an East Asian importer, but handles custom runs.
> http://www.newhavendisplay.com/vfd-c-586.html
> VFD do have a finite life, and darken as they age.  Samsung states 30,000
> hours to reach it 80% level (brightness).  You stated your unit has 83,000
> hours.
> DOUBLE CHECK DC Power and electrolytic capacitors associated with circuit,
> this has been known issue with commercial consumer appliances with VFD.
> The mfg. date on your unit may have been during "bad caps" decade.
> greg
> w9gb
> ==
> > I recently got in an HP-58503B GPSDO from a local equipment liquidation
> auction.
> > The unit has 83,000 hours of run time.  I think it was last powered up
> in 2013.
> >
> > The display (VFD) is a bit dim and blotchy.
> > Does anybody have a replacement display that would look better?
> > - Mark
> --
> Sent from iPad Air
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