19 Sep
2004
19 Sep
'04
2 a.m.
On Sep 19 2004, 5:24, Ed Kelleher wrote:
At 01:04 PM 9/18/2004, you wrote:
>In view of the recent discussion about which backplane(s) go with
which
>CPU(s) and some similar discussion on
alt.sys.pdp11, I've collected
>together some of my data on backplanes and chassis.
Bravo! What an excellent piece of work.
Thank you.
Thanks! It's not complete, though. For example, I don't know what's
in a BA212/BA213 (I believe it's a 12-slot straight Q/CD, but I don't
know the number), BA215 (6 slot?) or BA440 (same as BA213?), or in a
PDP-11/93 (I assume it's the same as an 11/83). And wasn't there a
very small backplane in one of the PDTs or Pros, or am I
misremembering?
--
Pete Peter Turnbull
Network Manager
University of York
19 Sep
19 Sep
2:19 a.m.
New subject: PDP8A chassis 50Hz
A PDP8A chassis is listed on eBay, in the USA
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=1247&item=51…
Wonder what someone will think when they find out it's 50Hz only.
It's in the pictures, but not in the writeup.
Ed K.
4:09 a.m.
New subject: PDP8A chassis 50Hz
A PDP8A chassis is listed on eBay, in the USA
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=1247&item=51…
Wonder what someone will think when they find out it's 50Hz only.
It's in the pictures, but not in the writeup.
Ed K.
That should not really matter that much, it is still 115 volts.
The block of iron in the transformer is a little overspec-ed for 60Hz.
Ed G.
7:18 a.m.
New subject: PDP8A chassis 50Hz
look at the capacitor connected to the transformer. That is a constant
voltage transformer and will need 50 hz to work correctly.
best regards, Steve Thatcher
At 09:09 AM 09/19/2004, you wrote:
A PDP8A
chassis is listed on eBay, in the USA
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=1247&item=51…
Wonder what someone will think when they find out it's 50Hz only.
It's in the pictures, but not in the writeup.
Ed K.
That should not really matter that much, it is still 115 volts.
The block of iron in the transformer is a little overspec-ed for 60Hz.
Ed G. 
7:48 a.m.
New subject: PDP8A chassis 50Hz
look at the capacitor connected to the transformer.
That is a constant
voltage transformer and will need 50 hz to work correctly.
Hey, I have one of these on a shelf as a "spare" 8/a chassis (with almost
enough spare boards to make a spare 8a :-)). I'd like to know if the 50Hz
turns out to be a strict requirement or not. If so, is there is any easy
way to convert the thing for 60Hz?
Thanks!
Vince
9:30 a.m.
New subject: PDP8A chassis 50Hz
On Sun, 19 Sep 2004, vrs wrote:
Probably replacing the capacitor (Oil or PCB) with one about 70% the
capacitance of the current one would be the easiest thing. This is to shift
the resonance up to 60 Hz. Be very careful of the resonant capacitor circuit,
it has quite high voltages...
Peter Wallace
look at the
capacitor connected to the transformer. That is a constant
voltage transformer and will need 50 hz to work correctly.
Hey, I have one of these on a shelf as a "spare" 8/a chassis (with almost
enough spare boards to make a spare 8a :-)). I'd like to know if the 50Hz
turns out to be a strict requirement or not. If so, is there is any easy
way to convert the thing for 60Hz?
Thanks!
Vince
11:34 a.m.
New subject: PDP8A chassis 50Hz
lowering the capacitance would work. The transformer may have a tap on it
where the cap connects to use 60 hz also. The chassis was "wired" for 50 hz
so the tag would have that rating on it. I would expect DEC would have kept
one transformer in stock and customized at mfg (maybe).
best regards, Steve
At 02:30 PM 09/19/2004, you wrote:
On Sun, 19 Sep 2004, vrs wrote:
Probably replacing the capacitor (Oil or PCB) with one about 70% the
capacitance of the current one would be the easiest thing. This is to shift
the resonance up to 60 Hz. Be very careful of the resonant capacitor circuit,
it has quite high voltages...
Peter Wallace
look at
the capacitor connected to the transformer. That is a constant
voltage transformer and will need 50 hz to work correctly.
Hey, I have one of these on a shelf as a "spare" 8/a chassis (with almost
enough spare boards to make a spare 8a :-)). I'd like to know if the 50Hz
turns out to be a strict requirement or not. If so, is there is any easy
way to convert the thing for 60Hz?
Thanks!
Vince
7223
days inactive
7223
days old
6 comments
6 participants
participants (6)
-
melamy＠earthlink.net -
pcw＠mesanet.com -
pete＠dunnington.u-net.com -
Pres＠macro-inc.com -
quapla＠xs4all.nl -
vrs＠msn.com