DIYAPASON-L Digest #290 - Thursday, March 29, 2001
 
Re:Cable routing - Was Diode location
  by "Tony Newnham" <organist@tsnp.fsnet.co.uk>
Anyone in the Dallas area near Plano?  (X-Posted)
  by "TommyLee Whitlock" <tommylee@whitlock.org>
 

(back) Subject: Re:Cable routing - Was Diode location From: "Tony Newnham" <organist@tsnp.fsnet.co.uk> Date: Wed, 28 Mar 2001 10:09:37 -0800   On Tue, 27 Mar 2001 11:44:19 EST Jon Fick wrote:-   Where might this be important? In my own scenario, I have console cabling that parallels PA system cabling for something like 90 feet. If I were to install diodes in the console expecting to kill the magnet spikes from the chests, then I can fully expect that I will have all sorts of magnetic fields spraying over that 90 feet and coupling into my PA system cabling. (Technical folks will be interested to know that the PA system cabling is = a 22-twisted pair snake and the mixer has differential inputs, but I'd say that 40-50 simultaneous pipe magnets whose reverse EMF currents are suppressed at the console could, intuitively, overcome the best = common-mode rejection at the mixer inputs.) Thus, I installed diodes at the 500+ magnets. I don't expect any PA system problems when we fire it up.     Don't do it! Running any audio cable - no matter ow well shielded and balanced, parallel to organ multiways, mains, or anything else is a = definite "No No". Sooner or later you will run into problems of interference. I lost a whole recording of a theatre organ concert - using proffessional recording gear - because of induction from the organ cable about 12 inches away from my mic lines, and only running parallel for about 3ft! Re-route one or other multiway if you possibly can!   Tony Newnham      
(back) Subject: Anyone in the Dallas area near Plano? (X-Posted) From: "TommyLee Whitlock" <tommylee@whitlock.org> Date: Thu, 29 Mar 2001 22:18:03 -0500   Hi all, I hope you don't mind too terribly the cross-post.   I will be going to the Plano, TX area near Dallas towards the end of April = on business. I may have some time on Saturday, the 21st and was wondering if =   there is anyone in the area who would be interested in meeting and = possibly seeing (and preferably hearing!) some of the instruments in the area. I'm = a beginner, but I wouldn't mind get to play a bit, too, but be warned! - my playing is still not very "house-trained". Also, if there are any performances in the area, on that weekend, perhaps I could arrange to = attend.   Please feel free to reply to me off list.   Cheers, TommyLee Whitlock tommylee@whitlock.org