[volt-nuts] Solartron 7061 help request (eeprom?) (Fred Schneider)

[Bill Ezell]

I have several 7061's and 7081's. They're both excellent meters and tend 
to hold calibration for a long time. My 7081 easily stays within a few 
ppm/year. (checked against my Fluke-calibrated Datron 4910's)

In answer to a few of the questions recently asked:

The battery is only for backing up stored readings and settings. The 
calibration values are in the eeprom, twice. So, unless it fails, you 
won't lose the calibration factors. The purpose of the eeprom refresh is 
just to do an read/erase/rewrite cycle. It was apparently a concern that 
eeproms of that vintage wouldn't store values over long times (years) 
reliably. I've not done a refresh on any of my 7061's and haven't had a 
problem.

As for heat, the 7061's do run very hot, but that's how they were 
designed. Not a good idea to put things on top of them without any 
airspace, though. The hottest area in a properly working 7061 is a small 
metal-shield box. It has some rather power-hungry IC's (74s series) in 
it, and it gets too hot to touch. Every 7061 I've ever seen is like 
that, so I assume it's operating as intended.

I wouldn't say the transformer runs hot in particular. If you're really 
seeing that, it's possible you have leaky caps in the power supply, 
although they'd have to leak a lot without exploding to raise the 
current drain enough to overheat the transformer. More likely is that 
it's a ventilation problem. Does your 7061 still have its feet to give 
it some airspace at the bottom?

-- 
Bill Ezell
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They said 'Windows or better'
so I used Linux.