conrad@tharr.UUCP (Conrad Longmore) (10/16/90)
We've just installed a lab with TeleVideo 9320 terminals. The terminals are great, except that we noticed the screens weren't straight. The lab is smallish, with 14 terminals in one part, and 14 old ATs in another, with metal benching and power & data cables running through trunking. I was about to jump down the throat of our supplier, when the thought occurred to me that there might be some interference, so I took the terminal into another room and tested it. It was OK. I put it back, and then turned off all the terminals, ATs & power in the lab, powering the terminal from another source. The problem remained. It looks like EMI from another source, or a magnetic field from the benching. Anyone had similar problems? Any solutions? -- // Conrad Longmore / Uucp: ..!ukc!axion!tharr!conrad / S*E*R*F says: Unix? // // Bedford College / Janet: tharr!conrad @ uk.ac.ukc / VMS? Plan 9? No way!// // Computer Centre / YelNet: +44 234 45151 x5350 / Long live Multics!! // // ** T H A R R ** / Free access to Usenet in the UK / ** 0234 261804 ** //
brian@Eyring.COM (Brian Cooper) (10/16/90)
In article <1096@tharr.UUCP> conrad@tharr.UUCP (Conrad Longmore) writes: >We've just installed a lab with TeleVideo 9320 terminals. The terminals >are great, except that we noticed the screens weren't straight. ...stuff deleted... >The problem remained. It looks like EMI from another source, or a magnetic >field from the benching. Anyone had similar problems? Any solutions? There is an office here where if you place a terminal against the back wall the display dances like crazy. Elsewhere in the office there is no problem. Turns out the power mains for the building are on the other side of the wall. You might try turning on a small radio and carrying it around to find where the noise is coming from. Our solution was just not to set a terminal there. Seems like some expensive shielding would probably do the job.
dnl@goanna.cs.rmit.oz.au (David "IGOR" Latter) (10/17/90)
We have some old visual 50 terminals here which have user selectable vertical scan rates. Here in Aust. we have 50 Hz mains supply, hence we need a 50 Hz vertical scan to reduce mains interference on the video display. The terminals do work on the other option of 60 Hz, but the display is somewhat unstable..... Check that the scan rates match your line frequency.