[vcf-midatlantic] Any trick to discharging ADM-3A

David Riley fraveydank at gmail.com
Thu Feb 8 12:12:32 EST 2018

On Feb 8, 2018, at 11:08 AM, Neil Cherry via vcf-midatlantic <vcf-midatlantic at lists.vintagecomputerfederation.org> wrote:
> My reference for the cold water pipe was for use with the screw driver
> to ground.

Well, the cold water pipe will connect to EARTH ground, which if your house is wired correctly should be the same as ground on your power outlets.  But since you're doing this with the system unplugged (you're doing this with the system unplugged, right?), it has no connection to the tube/chassis ground, which is what you really want.

In general, you want the shortest path possible to short it anyway; like Ian said, your best bet is to discharge the anode terminal straight to the other end of the capacitor that is the CRT glass by connecting to something metal directly connected to the glass (like the metal ears or the spring leads).

Remember also that glass does have a fair amount of electrical hysteresis; charges migrate slowly through it.  You may want to wait a few minutes and do a second discharge after the first to clear up any remaining charge.

- Dave

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