[time-nuts] HP-105B Battery Replacement?

Jeremy Nichols jn6wfo at gmail.com
Thu Sep 15 14:13:35 EDT 2016

Your point is well made. My question is: what happens to the quality of 
the output sine wave if I use anything other than a true sine-wave 
(i.e., expensive) UPS? Most of them these days produce a semi-sine wave 
(aka modified square wave) that may or may not play well with the 105B. 
Anyone have experience?

A external battery and appropriate chargers and cabling does sound like 
another good alternative. Harder to move around but I don't (yet) have 
such a need, only that the 105B stay "on" regardless of power failures.


On 9/15/2016 10:15 AM, Bob Camp wrote:
> Hi
> A bigger question becomes:
> Do batteries inside equipment make much sense anymore?
> These days, a UPS is often a standard part of a rack in an outage prone area. Powering
> the “whatever” instrument off of the same UPS as the rest of the stuff is one obvious
> answer.
> The other answer is an even older approach. Use a battery bank that is external to all
> the gear in the rack and tend it independently of each box in the rack. That way you have
> a few very large cells to worry about rather than a whole bunch scattered about. Things like
> lead acid that are impractical in a piece of gear are more of an option in an independent
> battery box. A single charger / line supply makes it easier to invest in something with real
> smarts in it. The advent of dirt cheap isolated switchers makes the conversion to instrument
> voltages a lot easier than it once was. Pick a common voltage like 12, 24, or 48V and run with it.
> My answer to the frequency standard battery pack question has become “don’t do it”. It makes
> them a *lot* lighter weight !!!
> Bob

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