Demagnetizer (can it be too strong?) - UK Vintage Radio Repair and Restoration Discussion Forum

Bruce · 6th Feb 2009, 4:30 am

I am looking about to purchase a tape head demagnitizer and many of those I have seen were designed for reel to reel tapes -- one I am looking at at the moment has quite large double "probes" rather than some of the smaller single "probe" one's I've seen touted for use with cassette decks.

I am wondering if these large units might be too strong when used on my cassette decks? (so is there a limit to the notion that more flux will do a better job )

bruce

Billy T · 7th Feb 2009, 12:32 am

When degaussing any item the only practical reason for limiting flux levels would be the potential to damage a physically delicate component such as a meter movement.

I work professionally in the field of electro-magnetics and I see no reason to limit flux levels when degaussing tape heads provided that the field is focussed on the head, otherwise nearby VU meters might suffer!

Make sure you move it well away (500mm) before switching off, but it is OK to turn it on when close to the head.

Cheers

Billy

ben · 7th Feb 2009, 12:56 am

I imagine using such a device on cheap midi systems and portables with permanent magnet erase heads might not be wise!

6th Feb 2009, 4:30 am	#1
Bruce Tetrode Join Date: Jan 2006 Location: Bangkok, Thailand. Posts: 85	Demagnetizer (can it be too strong?) I am looking about to purchase a tape head demagnitizer and many of those I have seen were designed for reel to reel tapes -- one I am looking at at the moment has quite large double "probes" rather than some of the smaller single "probe" one's I've seen touted for use with cassette decks. I am wondering if these large units might be too strong when used on my cassette decks? (so is there a limit to the notion that more flux will do a better job ) bruce

7th Feb 2009, 12:32 am	#2
Billy T Retired Dormant Member Join Date: Feb 2008 Location: Auckland, New Zealand Posts: 631	Re: Demagnitizer (can it be too strong?) When degaussing any item the only practical reason for limiting flux levels would be the potential to damage a physically delicate component such as a meter movement. I work professionally in the field of electro-magnetics and I see no reason to limit flux levels when degaussing tape heads provided that the field is focussed on the head, otherwise nearby VU meters might suffer! Make sure you move it well away (500mm) before switching off, but it is OK to turn it on when close to the head. Cheers Billy

7th Feb 2009, 12:56 am	#3
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: Demagnitizer (can it be too strong?) I imagine using such a device on cheap midi systems and portables with permanent magnet erase heads might not be wise! __________________ Regards, Ben.