[vcf-midatlantic] Tales from the lab

[Sentrytv]

I believe degaussing will also demagnetize the chassis in case it was near a very strong magnet which still could throw off the deflection of the image.
Even if it’s a monochrome display it couldn’t hurt.

Mike Rosen

Sent from:
My extremely complicated, hand held electronic device.

> On Dec 13, 2020, at 10:55 AM, Douglas Crawford via vcf-midatlantic <vcf-midatlantic at lists.vcfed.org> wrote:
> 
> 
> (oh wait, degauss... I guess that's just a color thing come to think of it. So much for being cute.)
> 
> On 12/8/2020 6:45 PM, Mike Loewen via vcf-midatlantic wrote:
>> 
>>    Dave McGuire and I ran into a mysterious problem while working on the LSSM's HP 3000 Series 39 minicomputer last month. We moved the 2645A console over next to the CPU for convenience and turned it on. The display was too wide, and characters were being cut off on the left side. No problem, says I, we'll just pop the top and make a quick video adjustment. We moved the terminal on top of the CPU to make it easier to work on, and adjusted the horizontal width. Moved the terminal back over where it was. The display was too wide again. WTF? Leaving the terminal where it was, we raised the top again to find that as the top was going up, the width was decreasing. As the top was lowered, it increased. It was only then that Dave and I simultaneously realized that the terminal was sitting on top of a 79XX series disc drives, with a large magnet in it.  Duh!  :-) 
>> 
>> 
>> Mike Loewen                mloewen at cpumagic.scol.pa.us 
>> Old Technology                http://q7.neurotica.com/Oldtech/