RK05 head alignment -- how difficult?

Fritz Mueller fritzm at fritzm.org
Mon Jul 24 13:38:26 CDT 2017

Thanks for the advice, per usual, folks!

To answer the question of "where hard to see", I guess it's really an issue of my old-man-eyes at this point.  I find I need to use a jeweler's headset, or even bench microscope, to really see anything small in detail these days.  It's hard to do that with heads in the drive -- I just can't get my head in there that close around all the fan, cartridge carriage, etc.  And seeing what's going on while trying to clean the top head with a mirror is pretty frustrating.  Perhaps it is time to find/train a younger apprentice :-)

I do have an alignment pack.  In looks to be in good shape.  I have not mounted it yet; after restoring the drives I figured if the heads were going to crash I would let that happen on less valuable media.  But to my pleasant surprise the heads flew (more or less) and I've been able to read packs reliably on the drive (including a DEC manufactured RKDP) without attempting a head alignment.  I did do the servo setup, but even all that was already very close to spot on.

If anybody has a decent picture of a clean/fresh RK05 head, I would appreciate seeing it -- there seems to be some material that is really caked on to the heads in my drive, and it would be nice to know for sure what my target is with cleaning, and/or if the heads are damaged.  in particular, what should the "wings" near the record/erase gap look like when clean and intact?

I'm finding it takes quite a bit of work to get gunk off the heads.  I'm using kimwipes and one other low-fiber lap wipe that is a little softer, and alcohol, and pushing/scrubbing these against the heads with swabs.  It has not been the case for me that they "clean right up".

Somebody asked about the "pox": these look to be corrosion of some sort.  Only one of my packs has had a bad case.  After scrubbing down with a wipe and alcohol, what is left behind is a little spider-like crack in the oxide layer.  In some places there seems to be corrosion between the aluminum and the oxide lifting and flaking the oxide.  It doesn't look like anything you'd want to try and fly a head over.

The recovered data has been kinda interesting -- the drives and packs were obtained in a surplus auction downstream of Stanford's Hansen Experimental Physics Lab.  They are mostly DOS/BATCH and RT-11 disks with Fortran and MACRO-11 codes relating to experiments at the lab in the mid-70's through early-80's: investigations into early resonant mass gravitation wave detectors and free electron lasers.  The names on the packs are readily found in related scientific literature of the time.  I've been working to track down the researchers where possible for permission to re-distribute the materials, since I think others might find them historically fun/interesting.

I'd be happy to retire these media after recovering the contents.  I don't know where to get fresher media to use afterword, though, that would necessarily be in any better shape?  If there are reputable resources for fresh media that folks know about I'd like to hear about that too!


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