DEC RX02 Maintenance

[J Blaser]

[NOTE: My apologies for raising issue of magnetic media all over again, but I can never seem to get the search function to work on the archives, so the best I can do is depend on Google to have some of the old threads in it's DB.  (Jay, this is not a criticism, I'm sure I'm doing something wrong, but in my two years on this list, I've never gotten anything out of the ht://Dig searcher, even with a simple word like 'diskette'.)]

I've started to image the hundreds of RX0n diskettes I have acquired from various sources for cataloging and preservation.  I'm using my real, live PDP-11/23PLUS with a dual-drive RX02 unit, and I've run into something I've never seen before.  Recent discussion has gone over the reliability of magentic media pretty well of late, but frankly, I was very, very surprised to see several of these 8" floppies shedding the oxide layer and leaving a transparent ring (okay, I flipped the diskette over hoping spinning it the other way briefly would help) in the substrate I can see through!  I was holding the diskette to the light to get a better look and discovered the oxide completely scrubbed off.

Track 0 was clearly (pun intended) a goner, so I tried my fingernail (lightly) and could just flake the oxide off of the substrate.  The brand is one I've never heard of, ANSCO, and gladly there are only a handful of this brand in my pile.  I've heard about this problem, here and elsewhere, but I was not prepared to experience it myself!

Anyway, the heads in the drives are now in serious need of cleaning, and I'll probably just dip a little isopropyl on a swap and see if I can get them clean.  But I've now found a new problem.  It looks like the little presser pad on my Drive 1 is missing on the top arm.  That may explain why that particular drive is sometimes less reliable at reading and writing.

Q: What's a good replacement material for the presser pad?  Can I simply use a little bit of dime-store felt, or is there something more exotic that I should use?

Also, since acquiring this system, and others, all with RX02 dual-drive units, I've notices some drives read more realiably than others, that is until I write to the diskette, then the landscape changes again, with respect to which drive will read that diskette reliably again.

Q: Is there a source for 8" alignment diskettes?  I recall one or two of the regulars on the list mentioning having them.  Is there a way to make a duplicate? Or at least to format a diskette on a drive that's been through the alignment gig?  It'd be nice to get my hands on one or the other.  I'm happy to spring for postage and refreshment.

Thanks.

- Jared