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Adjusting HP 59309A's LED Display Timing

RB
Rick Bollar
Fri, Mar 24, 2023 9:31 PM

Time-Nuts:

I added an HP 59309A Digital Clock circa 1975 to my esoteric clock collection. I am using a Spectracom SecureSync's 10 MHz output as an external frequency standard and the 59309A appears not to have gained or lost time over three months now. However, the LED display updates about 0.6 seconds after my other clocks and that messes with my OCD. Reading through the manual, it appears that adjustments via the programming language are limited to whole seconds, so I'm looking at other ways to deal with the problem. I'd like to get the LED display to update with the other displays. My questions:

  1. I want to confirm that this  ~0.6 second display update delay is normal and I'm not the only one that has this lag
  2. If this is normal, has it bothered anyone enough to do something about it? What did you do?

In the absence of an already baked solution, I'm thinking about making a 555 timer IC circuit to delay my 10MHz output by ~ 0.4 seconds and get the display updating in sync that way. Alternatively, TimeHat John Miller introduced me to the Leo Bodnar Precision GPS Reference Clock, which looks like it can do an offset on its second output. A little expensive, but the easiest solution I've found so far.

Thanks for your advice,

Rick

Sent from ProtonMail, Swiss-based encrypted email.

Time-Nuts: I added an HP 59309A Digital Clock circa 1975 to my esoteric clock collection. I am using a Spectracom SecureSync's 10 MHz output as an external frequency standard and the 59309A appears not to have gained or lost time over three months now. However, the LED display updates about 0.6 seconds after my other clocks and that messes with my OCD. Reading through the manual, it appears that adjustments via the programming language are limited to whole seconds, so I'm looking at other ways to deal with the problem. I'd like to get the LED display to update with the other displays. My questions: 1. I want to confirm that this  ~0.6 second display update delay is normal and I'm not the only one that has this lag 2. If this is normal, has it bothered anyone enough to do something about it? What did you do? In the absence of an already baked solution, I'm thinking about making a 555 timer IC circuit to delay my 10MHz output by ~ 0.4 seconds and get the display updating in sync that way. Alternatively, TimeHat John Miller introduced me to the Leo Bodnar Precision GPS Reference Clock, which looks like it can do an offset on its second output. A little expensive, but the easiest solution I've found so far. Thanks for your advice, Rick Sent from ProtonMail, Swiss-based encrypted email.