[time-nuts] 5061A questions

[wa1zms at att.net]

Morris-

NiCad & NiMh cells should be charged with a constant current source
which is what should be in the charging circuit of the 5061A.

For mine, I bought 4-cell packs of NiCad cells from Jameco here in
the US and wired enough packs in series to get the required number
for my 5061A.

Gell Cell and any other lead-acid battery technology requires a 
constant voltage charge so as to not over-charge the cells.  I would
not use them in your 5061A without first modifying the charger
to be a constant voltage type of the correct open circuit terminal voltage.

I have modified my HP105B to use Gell Cells, but I had to play games
with the charging circuit and make a zener diode change, resistor change,
etc....

It can be done, but NiCads are all not that too hard to find at least
here in the US.  But given time, they may go the way of the incandescent
light bulb. You know all about that one! :-)

-Brian, WA1ZMS

-------------- Original message ----------------------
From: "Morris Odell" <vilgotch at bigpond.net.au>
>
> Hi all,
> 
> I recently picked up another 5061A (my second now, I'm becoming a real
> Time-Nut :-). The tube seems to be OK, it started up nicely and has been
> working well for nearly a week. The Patek Phillipe clock ticks beautifully
> in sync with the first one which has a good tube too but runs most of the
> time from a Shera GPS controller built into the empty battery compartment.
> The time difference between the two has settled down to only a few nS up &
> down over the day. Unfortunately the counter I'm using, a 5345A, lacks the
> GPIB option so I can't record it.
> 
> This one has two mods I'm not familiar with - No 03 and No H92. There's a
> red LED labelled "System Alarm" on the front panel between the "Continuous
> operation" lamp and the 5 MHz output jack. There's also a DB25 female
> connector on the back marked "J30 Alarm". It lacks the little door on the
> top cover to allow adjustment of the clock and time offset - very
> frustrating.
> 
> There was a battery in it, disconnected and well past it's use-by date. The
> 20 NiCad cells have gone to the recycler.
> 
> My questions are:
> 
> What are those options?
> Can the battery charger be used with cells other than Nicads? 
> 
> Nicad cells are getting hard to find but there are plenty of NiMh cells
> around and also lead acid batteries. Is it worth setting up a battery? I
> have taken out the charger card temporarily. My first 5061A came without the
> card so I have no experience of this.
> 
> Cheers to all,
> 
> Morris
> 
> 
> 
> 
>  
> 
> 
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