[time-nuts] Boatanchor docs: HP AC-4 counter module manual

[Magnus Danielson]

David,

David Forbes skrev:
> O Nuts of Time,
> 
> I was recently asked to make a big PDF file of the HP AC-4 counter 
> modules manual that I have had on my website for a few years as a 
> series of jpeg files. So I did...
> 
> http://www.nixiebunny.com/hpac4/hpac4.pdf
> 
> These modules are used in the ancient HP 521 to 524 series of 
> counters. Each module handles one digit. They have four vacuum tubes 
> and either a nixie tube or ten neons in a thermometer arrangement.
> 
> I have a 521C and a 522B counter on hand but they are a bit too slow 
> to handle the 10 MHz of modern times, having a maximum counting 
> frequency of 200 kilocycles per second.

A pair of phantastron setups will divide it into range.
Should use up about 3 tubes.

Cheers,
Magnus