[time-nuts] Re: HP / Agilent 53132A

[Richard (Rick) Karlquist]

On 4/27/2023 4:34 PM, Brett Fanoga via time-nuts wrote:

> equipment leasing company for around $1100 US.  I have only had one 
> problem with mine, the fan failed.  It runs all the time, if the unit is 
> plugged in to power – even if the unit is off on the power switch. 
> Called HP and they do not sell the fan, they want to sell you the whole 
> power supply which they wanted a small fortune for.  But, I found 
> Digi-Key carried the exact fan, and I bought 2 units for just under $50 
> US about 10 years ago.  And now if I am not using the counter,  I unplug 
> it.
> 

I worked for the HP Santa Clara Division during the era of these 
instruments, which were code named "Major League Baseball" (MLB).  I suspect
(based on other HP instruments) that the fan is necessary to keep
the power transformer from overheating due to its own core loss.
And the power transformer is connected to the AC line at all times,
to save the hassle of a line level on/off switch, with all the
safety problems.  Fans running 24/7 are well known not to last for
more than a year or so.

And yes, vacuum fluorescents are famous for wearing out.  My N8LP
digital vector wattmeter puts the VF display to sleep after a
few minutes to extend the life.

Add on prescalers using dynamic flip flops are fairly fussy about
about broadband noise floor, etc.

This reminds me of a humorous anecdote.  I was in a meeting with
the designer of the MLB FPGA and Len Cutler.  The MLB engineer
offered his opinion about some technical issue, after which
he appended it with a self-deprecating remark along the lines
of "of course I've only been here for 30 years".  As if on
cue, Len angrily fired back with "well, I've been here 40 years".
This was classic Len behavior.  I kind of felt bad for the
MLB engineer.

Rick N6RK