[Info-vax] OT: the Daily WTF for today is a VAX/VMS story

[William Pechter]

In article <n9r2j6$s1r$1 at Iltempo.Update.UU.SE>,
Johnny Billquist  <bqt at softjar.se> wrote:
>On 2016-02-14 23:57, William Pechter wrote:
>> In article <n9quvs$l1l$1 at Iltempo.Update.UU.SE>,
>> Johnny Billquist  <bqt at softjar.se> wrote:
>>>
>>> So we are down to a separate starter motor? Fair enough, if you have
>>> that then yes, you can definitely do different tricks. But then you no
>>> longer have that simple AC motor.
>>>
>>> And I can tell you that the RP06 have no such thing. There is just one
>>> electric motor, and it's a DC one.
>>>
>>> 	Johnny
>>>
>>> --
>>> Johnny Billquist                  || "I'm on a bus
>>>                                    ||  on a psychedelic trip
>>> email: bqt at softjar.se             ||  Reading murder books
>>> pdp is alive!                     ||  tryin' to stay hip" - B. Idol
>>
>>
>> What the.  IIRC, RP06's have the same 220 AC motor that I remember changing.
>> IIRC the same motor's in either my washing machine (20 years old or so)
>> or my electric clothes drier... Big heavy and 220 volt.
>>
>> No way that's a DC motor.  Two phase -- yes.
>
>Just read through the service manual.
>Check 
>http://www.mirrorservice.org/sites/www.bitsavers.org/pdf/dec/disc/rp04_rp05_rp06/RP05_06_DriveMaintMan_Dec75.pdf, 
>page 3-102 (or page 90). There you have +50V to the motor control.
>I can't find any other motor feed. However, you got me wondering some 
>more, since you are supposed to have a different motor for 50Hz and 60Hz 
>operation, which would suggest that it should be AC. But power is wired 
>either wye or delta, depending on what your power source is.
>
>It's getting too late, and I really should stop reading old manuals. 
>I'll accept that I remember wrong, and that it's an AC motor after all. 
>But not a synchronous one...
>
>	Johnny
>
>
>
>-- 
>Johnny Billquist                  || "I'm on a bus
>                                   ||  on a psychedelic trip
>email: bqt at softjar.se             ||  Reading murder books
>pdp is alive!                     ||  tryin' to stay hip" - B. Idol

No problem... Lifted enough of them into place to bolt them up.
Not synchronous -- ok... never checked the specs on that but probably
you're right.  

Looks like Memorex made these supporting 60 and 50hz in both Delta and 
Wye configs (pg 7).

http://mrxhist.org/docs/MRX%2019790532%20Brochure%20677.pdf

Large heavy and IIRC three big pain bolts to hold the weight.  Never
saw a DC motor that big... remember replacing starter cap once.

They talk about a Dolphin tester on page 5 -- DEC used a Perch tester.
(Probably modified due to DEC's change on some logic...)

While researching I found this interesting RP04 photo... this one was
three phase.

http://www.columbia.edu/cu/computinghistory/rp04.html

There once was a guy who worked on the Memorex assembly line who supposedly
got fired for putting Tide Laundry detergent sample boxes in the RP06's
at ship time.  According to my RP06 maintenance instructor -- most of these 
were removed at DEC when they checked the drives out before shipping. 

I assume DEC added the DCL's in house on the modified 677-1 drives.

However, someone received one and called DEC which brought the wrath of
the front office down on Memorex and the tech got canned.

This from my old RP06 maint teacher (mumble) Arsenault... might have been
Bob or Jim... Can't remember that far back.  We had one of the rare
RP04-2 drives (which officially became an RP05) in the class for 
demonstrations.

The memorex versions of the drives used to display active cylinder in lights
on the RP06 front panel.  Not supported in the DEC version.

Bill
-- 
-- 
Digital had it then.  Don't you wish you could buy it now!
pechter-at-gmail.com  http://xkcd.com/705/