11 Sep
2008
11 Sep
'08
3:24 p.m.
This is probably an old question but, well, I'm new to the list...
Is there a known substitute CRT (both mfr and p/n) for the tube that is
in a DEC VR201 monitor such as used with a DEC Rainbow?
I have a VR201 that has the infamous mold on the inside of the tube's
face. I am not up to peeling the face off and trying to fix it so am
interested in just swapping out the tube.
After going through all the docs I can find, I never did come up
with a mfr or p/n for the tube itself so don't have a way to do a
cross-reference.
Of course if anyone has a non-moldy, b/w or amber VR201 that they want
to get rid of... say the word.
Chris
--
Chris Elmquist
mailto:chrise at pobox.com
12 Sep
12 Sep
11:18 a.m.
This is probably an old question but, well, I'm new to the list...
Is there a known substitute CRT (both mfr and p/n) for the tube that is
in a DEC VR201 monitor such as used with a DEC Rainbow?
I've never had t oreplace the CRT in a VR201, but my experience is that
small monochrome CRTs are pretty generic (there are 2 main families), and
from what I can find about the intenrals of the VR201
it's a very
standard monitor with normal-looking voltages on the CRT.
The 2 families are basically :
Narrow nexk with a 7 pin base (modified B7G -- modified in that the
sealing tube is in the middle of the pins)) and a 12V filament
Wider neck with an 8 pin base (B8H) and a 6.3V filament.
You need one of the former type. Oh, and it's a 90 degree deflection
angle. I've never seen a wider deflection angle in a computer terminal or
monitor, but some UK portable TVs had 105 degree CRTs that are not
suitable here.
The other issue is the mouting. I can't rememebr if the VR201 CRT has
fixing lugs on the tension band or not. Obviously you need one with the
same mounting arrangements. Do not, whatever you do, try to mofify or
remove that tension band!
But my guess is that putting any CRT that will physically fit in will
work. You may have to tweak the focus and G2 presets, that's all
I would not ne at all suprised if the CRT from a DEC terminal worked...
-tony
12:44 p.m.
Chris Elmquist wrote:
Of course if anyone has a non-moldy, b/w or amber
VR201 that they want
to get rid of... say the word.
Not that terribly many years ago, one couldn't walk down the aisles of
electronic surplus stores without tripping over piles of VR201s. I
guess those days are gone.
1:50 p.m.
On Friday (09/12/2008 at 12:44PM -0700), Eric Smith wrote:
Chris Elmquist wrote:
Not that terribly many years ago, we actually used to have electronic surplus
stores around here :-)
Those days are definitely gone.
Chris
--
Chris Elmquist
mailto:chrise at pobox.com
Of course if anyone has a non-moldy, b/w or amber
VR201 that they want
to get rid of... say the word.
Not that terribly many years ago, one couldn't walk down the aisles of
electronic surplus stores without tripping over piles of VR201s. I guess
those days are gone. 
2:46 p.m.
In article <48CAC683.4010201 at brouhaha.com>,
Eric Smith <eric at brouhaha.com> writes:
Chris Elmquist wrote:
Depending on where you live, those days were never here in the first
place.
I would expect that only in Silicon Valley or on the 128 beltway would
those days have ever been "here".
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://www.xmission.com/~legalize/book/download/index.html>
Legalize Adulthood! <http://blogs.xmission.com/legalize/>
Of course if anyone has a non-moldy, b/w or amber
VR201 that they want
to get rid of... say the word.
Not that terribly many years ago, one couldn't walk down the aisles of
electronic surplus stores without tripping over piles of VR201s. I
guess those days are gone.
2:52 p.m.
I wrote:
Not that terribly many years ago, one couldn't
walk down the aisles of
electronic surplus stores without tripping over piles of VR201s. I
guess those days are gone.
Richard wrote:
Depending on where you live, those days were never
here in the first
place.
I would expect that only in Silicon Valley or on the 128 beltway would
those days have ever been "here".
No, I used to routinely see piles of them in surplus outfits in
Colorado, Kansas, Missouri, and Nebraska. They weren't huge piles, so I
was exaggerating a bit, but they definitely weren't at all difficult to
find.
Eric
3:42 p.m.
On Fri, Sep 12, 2008 at 02:52:34PM -0700, Eric Smith wrote:
I wrote:
At the right point in time, somewhere around 10 years ago, I think,
I remember seeing medium-sized piles of DEC Professionals in various
places in Ohio - hamfests, flea markets, university surplus, etc.
IIRC, it was easy to pick up a Pro CPU, LK201 and VR201 for around $20
for months. I haven't seen any around the same sorts of places in over
five years.
Some time ago, I myself was looking for a replacement VR201 tube. I
had been using one on an Amiga 2000 (after fitting a DA15 to the Amiga,
wired for mono video and +12V to power the monitor). The Amiga was
in a Bomac Tower case, and the VR201 was on top, until one day when I
knocked it off and let the vacuum out of the tube. :-( After years
of not finding a tube, I may have thrown out the enclosure, but I know
I saved the board in case one of my other VR201s dies electronically.
As for tripping over piles of anything, over the years I've seen,
especially at the Dayton Hamfest, alternating piles of outgoing
technology that hit the spot where tons of it were dumped on the
market. One year, everyone seemed to be selling EGA monitors when
VGA first took hold. Another year, several vendors were all selling
Informer brand portable SNA terminals. Yet another year, you couldn't
turn down an aisle at Dayton without tripping over piles of 386
motherboards. If you have the space, it's best to take advantage of
these cycles when they happen, along a classic bathtub curve, eventually,
due to scarcity, prices will inch back up.
Witness PDP-8 prices over the last couple of decades... in 1981, I
picked up a PDP-8/L for $35. Shortly before that, I know some list
members who got PDP-8/Ss for about that. They went from $10K to under
$100 in 10-15 years, then vanished from the easy-to-find places, and
now are very difficult to find, even for many times their lowest
historical prices. Being peripherals, VR201s probably won't undergo
the same intensity of price-swing, but to a lesser magnitude, the
effect is the same.
-ethan
--
Ethan Dicks, A-333-S Current South Pole Weather at 12-Sep-2008 at 22:10 Z
South Pole Station
PSC 468 Box 400 Temp -47.6 F (-44.2 C) Windchill -70.4 F (-56.9 C)
APO AP 96598 Wind 6.1 kts Grid 54 Barometer 678.9 mb (10670 ft)
Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html
Not that terribly many years ago, one
couldn't walk down the aisles of
electronic surplus stores without tripping over piles of VR201s. I
guess those days are gone.
Richard wrote:
Depending on where you live, those days were never
here in the first
place.
I would expect that only in Silicon Valley or on the 128 beltway would
those days have ever been "here".
No, I used to routinely see piles of them in surplus outfits in
Colorado, Kansas, Missouri, and Nebraska. They weren't huge piles, so I
was exaggerating a bit, but they definitely weren't at all difficult to
find.
5:04 p.m.
In article <20080912224236.GA3524 at usap.gov>,
Ethan Dicks <ethan.dicks at usap.gov> writes:
As for tripping over piles of anything, over the years
I've seen,
especially at the Dayton Hamfest, [...]
As I've pointed out on the list before: it all depends on where you
live.
I've never seen or heard about a hamfest in Utah for the 20 years I've
been living here and the 5+ years I've been collecting vintage
computing gear.
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://www.xmission.com/~legalize/book/download/index.html>
Legalize Adulthood! <http://blogs.xmission.com/legalize/>
6:15 p.m.
Richard wrote:
I've never seen or heard about a hamfest in Utah
for the 20 years I've
been living here and the 5+ years I've been collecting vintage
computing gear.
There certainly were some when I lived in Utah from 1984-1986.
A quick search confirms that they've had some in more recent years:
http://www.utahhamfest.org/
5:41 p.m.
On Friday (09/12/2008 at 02:52PM -0700), Eric Smith wrote:
No, I used to routinely see piles of them in surplus outfits in Colorado,
Kansas, Missouri, and Nebraska. They weren't huge piles, so I was
exaggerating a bit, but they definitely weren't at all difficult to find.
I'd venture that many of the surplus houses dumped them and many other
kinds of CRTs while they could still do it for free. Now, it can cost
as much as the CRT did new to dispose of them.
Thanks to all who responded on the tube substitution question. I'll
do some more research and see if I can identify a tube that will fit.
I'm also toying with the idea of fitting an LCD into a VR201 cabinet
and although it wouldn't be authentic, it would sure make the system
more useable.
I also have the option of using an RGBHV to SVGA converter along with the
Rainbow color graphics card to get output on an LCD but that doesn't seem
as attractive as the little VR201 with the "digital" logo at the bottom.
Chris
--
Chris Elmquist
mailto:chrise at pobox.com
13 Sep
13 Sep
12:52 p.m.
I'm also toying with the idea of fitting an LCD
into a VR201 cabinet
and although it wouldn't be authentic, it would sure make the system
more useable.
I am curious as to why an LCD in the VR201 cabinet is more useable than
the CRT. I can't see much difference in useability (but would much rather
have to repair a CRT_based monitor than an LCD-based one).
-tony
1:59 p.m.
On Saturday (09/13/2008 at 08:52PM +0100), Tony Duell wrote:
Well, if I can't find a tube to replace it... then I'd consider an LCD.
I also have a serious heatload problem in the "museum" here and the
more things I add that make heat, the more uncomfortable it gets sitting
around using the stuff.
Repair of the unit after the LCD was swapped in would be by replacing
the entire LCD subsystem. But-- I'm betting that if the LCD survives
the first few hours of life, it will then probably outlive me and it
becomes the next guy's problem to repair it :-)
I think what I really need to do is just come to terms with looking
through the fog. The monitor works fine otherwise-- nice and bright
and no burn-in so the whole issue is strictly cosmetic.
Chris
--
Chris Elmquist
mailto:chrise at pobox.com
I'm also
toying with the idea of fitting an LCD into a VR201 cabinet
and although it wouldn't be authentic, it would sure make the system
more useable.
I am curious as to why an LCD in the VR201 cabinet is more useable than
the CRT. I can't see much difference in useability (but would much rather
have to repair a CRT_based monitor than an LCD-based one).
15 Sep
15 Sep
2:03 p.m.
On Saturday (09/13/2008 at 08:52PM +0100), Tony Duell wrote:
Well, if I can't find a tube to replace it... then I'd consider an LCD.
Do you really have no old 12" monchrome portable TVs/monitors around? I
am sure you could find a CRT that would work.
I'm
also toying with the idea of fitting an LCD into a VR201 cabinet
and although it wouldn't be authentic, it would sure make the system
more useable.
I am curious as to why an LCD in the VR201 cabinet is more useable than
the CRT. I can't see much difference in useability (but would much rather
have to repair a CRT_based monitor than an LCD-based one). Repair of the unit after the LCD was swapped in would
be by replacing
the entire LCD subsystem. But-- I'm betting that if the LCD survives
Assuming you could get one.... I can see you having the same problem as
finding a replacement CRT now...
the first few hours of life, it will then probably
outlive me and it
becomes the next guy's problem to repair it :-)
Well, in all my classic computers I've had one CRT fail. That was in a
Volker-Craig terminal and amazinging the weld between the cathode and its
base pin factured, so there was no cathode current (no, I don't mean
heater/filament here). I remember raiding a CRT from another old monitor,
popping it in and having no problems.
I've had 2 or 3 LCD panels fail, due to the ceals between the 2 class
plates failing and the liquid crystal itself leaking out. The panel turns
black from one corner/edge since without the LC material, the plane of
polarization of the light is no longer twisted, so the 2 external crossed
polarisers son't transmit much.
In terms of the driver circuitry, I don't think I've had an LCD driver
chip fail. Of course I've had CRT drivers fail, but normallly an
easy-to-get component, like a transistor, dies.
I think what I really need to do is just come to terms
with looking
through the fog. The monitor works fine otherwise-- nice and bright
and no burn-in so the whole issue is strictly cosmetic.
I've never tried to remove and re-bond a faceplate, but I've heard others
have mamanged it.
-tony
16 Sep
16 Sep
5:53 a.m.
On Monday (09/15/2008 at 10:03PM +0100), Tony Duell wrote:
Actually, there are a number of LCD "modules" that are good candidates.
These are basically LCD TVs and end up in planes, trains and automobiles
so people can watch DVDs instead of staring at the back of a seat.
I've seen those efforts discussed. I think I'll pass on that operation
because it could truely be a destructive procedure. At least now, the
monitor works and just looks crappy. After blowing apart the CRT while
trying to peel the front off, I'd really be behind the curve :-)
Chris
--
Chris Elmquist
mailto:chrise at pobox.com
Do you really have no old 12" monchrome portable TVs/monitors around? I
am sure you could find a CRT that would work.
No... there was a dark period in my life when I decided to get rid of all
that stuff... even had a Zenith ZVM-1240 monitor (and of course the Z100
to go with it!) which I gave away.
http://www.recycledgoods.com/images/s_p_17993_1.jpg
Wouldn't that have been a good replacement?
Repair of the
unit after the LCD was swapped in would be by replacing
the entire LCD subsystem. But-- I'm betting that if the LCD survives
Assuming you could get one.... I can see you having the same problem as
finding a replacement CRT now... I think what I
really need to do is just come to terms with looking
through the fog. The monitor works fine otherwise-- nice and bright
and no burn-in so the whole issue is strictly cosmetic.
I've never tried to remove and re-bond a faceplate, but I've heard others
have mamanged it.
17 Sep
17 Sep
1:26 p.m.
Repair of the unit after the LCD was swapped in would
be by replacing
the entire LCD subsystem. But-- I'm betting that if the LCD survives
Assuming you could get one.... I can see you having the same problem as
finding a replacement CRT now... I think what I really need to do is just come to terms
with looking
through the fog. The monitor works fine otherwise-- nice and bright
and no burn-in so the whole issue is strictly cosmetic.
I've never tried to remove and re-bond a faceplate, but I've heard others
have mamanged it. 
14 Sep
14 Sep
12:20 p.m.
Tony Duell wrote:
Well if the CRT is gubbed, it's not going to be terribly usable, is it?
Gordon
I'm also
toying with the idea of fitting an LCD into a VR201 cabinet
and although it wouldn't be authentic, it would sure make the system
more useable.
I am curious as to why an LCD in the VR201 cabinet is more useable than
the CRT. I can't see much difference in useability (but would much rather
have to repair a CRT_based monitor than an LCD-based one). 
12 Sep
12 Sep
6:19 p.m.
On Sep 12, 2008, at 5:52 PM, Eric Smith wrote:
I wrote:
I think those days are LONG gone. I don't even see them on eBay
very often. I sure wish I had picked up a few spares before they
dried up. But of course I can say that about a great many things.
-Dave
--
Dave McGuire
Port Charlotte, FL
Not that terribly many years ago, one
couldn't walk down the
aisles of
electronic surplus stores without tripping over
piles of VR201s. I
guess those days are gone.
Richard wrote:
Depending on where you live, those days were
never here in the first
place.
I would expect that only in Silicon Valley or on the 128 beltway
would
those days have ever been "here".
No, I used to routinely see piles of them in surplus outfits in
Colorado, Kansas, Missouri, and Nebraska. They weren't huge piles,
so I was exaggerating a bit, but they definitely weren't at all
difficult to find.
5941
days inactive
5947
days old
16 comments
7 participants
participants (7)
-
ard＠p850ug1.demon.co.uk -
chrise＠pobox.com -
eric＠brouhaha.com -
ethan.dicks＠usap.gov -
gordonjcp＠gjcp.net -
legalize＠xmission.com -
mcguire＠neurotica.com