Keep Your Heads Clean - UK Vintage Radio Repair and Restoration Discussion Forum

ruffrecords · 2nd Oct 2006, 10:27 am

Just been having some fun getting my old high speed A77 up to scratch and changing the replay EQ to IEC from NAB. In doing this I checked the replay response several times with my Sudio Magnetics replay alignment test tape. The 16KHz response was typically more than 6dB down. I was not overly concerned about this as many recorders I have tested have been similar. However, as a check I looked at the response of the lower track as well (I was just testing the upper track before) and to my surprise its 16KHz response was much better. Now I had had a problem on another machine years ago with head tilt which cuased a similar effect so off I go to the manual to look at how to adjust this -DO NOT ADJUST THIS says the manual. So I thought maybe I just live with it but just to be sure I'll check the replay head cleanliness (I had cleaned the heads several times before). On very close inspection with a torch and magnifying glass I noticed a small piece of crud right near the top of the replay head upper track (where you normaly cannot see). It took a real hard rub with head cleaner to get it off so it may well have been there some time. Needless to say, the reproduce alignment test on the upper track was now as good as the lower.

Moral - Don't just clean your heads; check them over with a torch and magnifying glass.

Ian

Bob955i · 2nd Oct 2006, 10:58 am

I've heard of instances on 2" multitracks where a buildup of oxide/crap resulted in the tape being slit lengthways while running.

2nd Oct 2006, 10:27 am	#1
ruffrecords Retired Dormant Member Join Date: Sep 2006 Location: Cromer Posts: 41	Keep Your Heads Clean Just been having some fun getting my old high speed A77 up to scratch and changing the replay EQ to IEC from NAB. In doing this I checked the replay response several times with my Sudio Magnetics replay alignment test tape. The 16KHz response was typically more than 6dB down. I was not overly concerned about this as many recorders I have tested have been similar. However, as a check I looked at the response of the lower track as well (I was just testing the upper track before) and to my surprise its 16KHz response was much better. Now I had had a problem on another machine years ago with head tilt which cuased a similar effect so off I go to the manual to look at how to adjust this -DO NOT ADJUST THIS says the manual. So I thought maybe I just live with it but just to be sure I'll check the replay head cleanliness (I had cleaned the heads several times before). On very close inspection with a torch and magnifying glass I noticed a small piece of crud right near the top of the replay head upper track (where you normaly cannot see). It took a real hard rub with head cleaner to get it off so it may well have been there some time. Needless to say, the reproduce alignment test on the upper track was now as good as the lower. Moral - Don't just clean your heads; check them over with a torch and magnifying glass. Ian

2nd Oct 2006, 10:58 am	#2
Bob955i Retired Dormant Member Join Date: Nov 2005 Location: Leven Posts: 38	Re: Keep Your Heads Clean I've heard of instances on 2" multitracks where a buildup of oxide/crap resulted in the tape being slit lengthways while running.