Jay wrote: Hmm, I said that you could inspect the brushes of the spindle motor. Get an AM radio and listen to the interference (if it is audible). As to why Allison doesn't seem to have this problem, she probably does not have the RFI source you have in the RX02 :-) Perhaps your RX02 is only missing a simple wire to connect "something" to the frame of the RX02 to ground whatever ... - Henk. This message and attachment(s) are intended solely for use by the addressee and may contain information that is privileged, confidential or otherwise exempt from disclosure under applicable law. If you are not the intended recipient or agent thereof responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by telephone and with a 'reply' message. Thank you for your co-operation.

On 5 Apr 2007 at 1:09, Jay West wrote: I wonder if it's more EMI than RFI, because it reminds me of a nasty problem we had when developing the Durango F85. If you look at the machine, there's a 9-inch CRT placed above the dual floppy drive. Before we actually had a production model, we worked from a lash-up with a keyboard connected to a card cage connected to the PSU, monitor and diskette drives--all laid out on a benchtop in traditional develpment fashion. It all worked fine. Then came the first production prototypes. Naturally, the initial ones were given to the marketing people to take pretty pictures of and show around at shows and to prospective customers. The software folk were the last to get a real one. Except for one problem... The diskette drives refused to work on the production model. Grounding braid was added, power supply connections were re-routed and everything else was tried. Nothing worked--but the laid-out-on- the bench lash-up worked perfectly, even when the production cards and drives were substituted. But the pretty production models refused to even boot. The engineers were baffled--until someone took the monitor off of the top of the diskette drive area to attach a scope probe--and the problem went away. It turns out that the FBT was kicking up noise something fierce in the read channels of the diskette drives. An shield made of sheet aluminum didn't get rid of the problem, but one made of steel worked just fine. We also added a shield around the paper feed stepper--it seems that when a line- or form-feed was performed, the CRT image shuddered something awful. Cheers, Chuck

The plot thickens.... 1) I took tony's suggestion and disconnected the AC on both RX02 spindle motors from the back. The problem still occurs so it's not the RX02 spindle motors. 2) I extended the RX02 on the rails and looked underneath. There is a metal plate bolted under each drive. I believe it's steel, it's that burnished "gold" colored metal. There is a separate flat plate under each drive, and the plate L's up the side about 3/4 of an inch. I believe this is properly closed. 3) I put that steel plate between the RL02 and RX02 again and sure enough the problem disappears. This time I tried moving the plate around to localize exactly what on the RL02 must be covered to keep the problem from occuring. This may be telltale. The portion of the drive that needs to be covered by the metal plate to keep the problem from occuring is the top back cover of the RL02. This is the plastic section that is about 8 inches deep front to back, and is exactly over the drive logic board. Interesting that this would mean the plate isn't covering the heads. Also interesting - based on the depth difference between the RX02 and RL02, no part of the RX02 extends over that part of the RL02 EXCEPT the black "wedge" fan housing and fan on the back. 4) I believe that there is supposed to be some type of cover over the top of the RX02. I do not have this cover. I have what I was TOLD is the top cover of the RX02, but there's no way it could possibly fit over the top. I know that a rackmounted RX02 doesn't have a nice finished metal cover, but I do think there is some type of metal cover that is supposed to be on top. I wouldn't have thought this to be so germane to the problem, because the problem is definitely "down and to the rear" from the RX02. 5) The problem with the right drive - I forgot to check this closely, but I am fairly sure that drive spins. But if you put a boot disk in it (that works fine in the left drive) the heads will drop and lift over and over with about 2 or 3 seconds between each drop/lift cycle. It'll do this till I halt the processor. Maybe all the above will trigger a course of action in the brain of someone smarter than me :) Jay

I have RX02's rack-mounted with a top cover. However, the top cover is *not* attached to the RX02 drive. It is separately mounted just above the drive in the rack by 2 standard screws at each side to the vertical post. Sort of "dust cover". - Henk. This message and attachment(s) are intended solely for use by the addressee and may contain information that is privileged, confidential or otherwise exempt from disclosure under applicable law. If you are not the intended recipient or agent thereof responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by telephone and with a 'reply' message. Thank you for your co-operation.

The metal on top of the RX02 assembly is screwed to the rack. I think it's basically to keep things out of the power supply and off the contacts to the caps. It could also be an RF/EMI Shield. One guy in DEC Field Service neglected to screw it in one day and when I worked on the VAX I came in contact with it and the RX02 power supply on the 11/750. I'll never forget that. Bill On 4/6/07, Gooijen, Henk <henk.gooijen at oce.com> wrote: -- -- d|i|g|i|t|a|l had it THEN. Don't you wish you could still buy it now! pechter-at-gmail.com

On 06/04/2007 14:30, Jay West wrote: I stand corrected. I'd not paid that much attention to the user manual, and none of the RX02s I've come across were associated with a cover, so I assumed it didn't exist. But given the number of people here who have one, or seen one, they're not *that* rare. Drat, that's something else I need to look for now ;-) -- Pete Peter Turnbull Network Manager University of York

Hi All it has to do is reduce the magnetic field. I doubt there is much issue with an electrical field. Most recording machines are quite sensitive to stray magnetic fields while recording. I'm not sure how much aluminum would reduce magnetic fields unless it was high frequency. I'd suspect that most 60 cycle would go right through it with little loss. Dwight _________________________________________________________________ Need a break? Find your escape route with Live Search Maps. http://maps.live.com/?icid=hmtag3

Thgat suprises me, but you can't argue with the results. Yes. That's the correct underside covers for an RX02. I assume you've tried disconencting the fan temporarily (the RS02 will not overheat that quickly). THere were several types of fan used, most RX's have a normal 'muffin fan', but I've seen one with a strange thing with a small shanded-pole motor on brackets. There's a U-shapped metal cover that mounts _separately_ in the rack (it screws to the front uprights of the rack. When you pull the RX02 out, the cover stays behind (ovviosuly) so you can easilly work on the RX02. -tony