Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Tom Knox
A Josephson Junction is not a Cesium Standard. It is not quite to the Plug and Play level. And takes a few racks worth of space. Operation and Maintenance is more difficult then most calibrations. But big advances are being made. At some point in the not to distant future I foresee JJ arrays bei

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Chuck Harris
Of course you would need to calibrate a JJ standard. If you recall, the JJ works by being cooled to some LN2 like temperature, and then being fed with a microwave frequency that is part of the standard's definition. If the temperature is wrong, or the frequency is wrong, or ..., the voltage will

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Joe Hobart
Bill, Would a Josephson Junction standard need to be calibrated? Adjusted and maybe compared, yes, but you should not need to calibrate a primary standard? Years ago we had HP Cesium Frequency Standards at work. There were primary standards and good to 4E-12 with no additional calibration. Joe

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Tom Miller
Can you imagine what it would cost to get that calibrated? Tom - Original Message - From: "Bill Gold" To: "Discussion of precise voltage measurement" Sent: Saturday, January 18, 2014 5:17 PM Subject: Re: [volt-nuts] What made a HP3458A so expensive In fact if you look at a 1982 HP c

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Dr. David Kirkby
On 18 January 2014 21:15, Bill Gold wrote: > I did have a display that was going dim on one digit so I ordered a new VFD > display from Agilent, not the whole board just the actual display. When I > compared it to the original I found that the top to bottom distance between > the pins was larger

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Bill Gold
In fact if you look at a 1982 HP catalog you will see that the 3456A was selling for around $3,700 and given inflation the 3458A is still a pretty good bargain when it was introduced in 1989. In 1989 the 3456A was selling for $4,600 while the 3458A was selling for $5,900. I wonder if there will e

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Bill Gold
There is one other issue with the stability of the LTZ1000A besides aging. In leaving it unpowered for a long period of time the junctions are not biased and if there is any contamination present from the fabrication of the wafers, the free contamination ions can migrate back to the junctions and c

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Tom Knox
Actually in spite of it's high price I feel the 3458A represents a bargain. When it was introduced in 1989 it was $5900. A price it held for decades. Although designed in then 80's it's accuracy is still unsurpassed. The 8846A is much less expensive because it has only about a quarter the part

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Bill Gold
I did have a display that was going dim on one digit so I ordered a new VFD display from Agilent, not the whole board just the actual display. When I compared it to the original I found that the top to bottom distance between the pins was larger than the original display. So I had to carefully be

Re: [volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Poul-Henning Kamp
In message , Mark Sims writes: >One problem with leaving the 3458A on all the time is the vacuum >fluorescent display. These have a rather limited lifetime and >leaving them on 24/7 puts a lot of hours on the tube. Someday those >displays will become unobtainium... That's a smaller catastrophe

[volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Mark Sims
One problem with leaving the 3458A on all the time is the vacuum fluorescent display. These have a rather limited lifetime and leaving them on 24/7 puts a lot of hours on the tube. Someday those displays will become unobtainium... _

[volt-nuts] What made a HP3458A so expensive

2014-01-18 Thread Frank Stellmach
Well, the 3458A now is in production for about 25 years , and only around 50k units have been sold. (That's an estimation by Joe Gellers series number collection) As the 3458A is a niche product with homeopathic series volume, the development, verification/validation, special reliability engi

Re: [volt-nuts] Extender Card for Guildline 9975

2014-01-18 Thread Dr. David Kirkby
On 18 Jan 2014 14:38, "Joe Hobart" wrote: > Does anyone have or know where I can buy or borrow a 12/24 contact > extender card > for the Guildline 9975? I have a single sided extender, but the signal > demodulator board requires a double sided extender. Of course, it is this > card > that needs

[volt-nuts] Extender Card for Guildline 9975

2014-01-18 Thread Joe Hobart
Does anyone have or know where I can buy or borrow a 12/24 contact extender card for the Guildline 9975? I have a single sided extender, but the signal demodulator board requires a double sided extender. Of course, it is this card that needs additional testing and possible repair. Thank you, Joe