Gemstar VCRPLUS clock accuracy

[UCLAN]

root wrote:

Again I didn't make myself clear: The unit allows you to set
the hour without setting any other value. That is the only
change I ever did. Twice a year I would set the hour to adjust
for daylight/standard time. The unit held all values when the
batteries (4) were changed.

But lost the amount of time it took you to replace the batteries.
So over 20 years you've spent less than a minute replacing batteries?

 

[isw]

In article
<bf44c9db-be40-46d4-9290-023da27e6029@v25g2000yqk.googlegroups.com>,
"William R. Walsh" <wm_walsh@hotmail.com> wrote:

Hi!

Sure, the first unit I picked up was a Gemstar VIP-18. I
think there a previous unit VIP-08. It is 7"x2.5"x.75"
and runs on 4 AA cells. The unit was (c) 1990.

I see there's one on eBay at present that would cost a princely $3 and
shipping to buy. I'm half tempted, just to crack it open and answer
your question.

There are good battery operated quartz clocks, and some of them will
keep very good time. But if those things have stayed accurate to
within a minute over twenty years, they *have* to be getting a time
reference from somewhere. Battery operated clocks just aren't that
stable over long periods of time because of a lot of factors, not the
least of which is battery drain over time.

And temperature drift, and age-related drift, and shock, and ...

(Power line clocks, on the other hand, can be startlingly stable.)

Dead nuts over the long term (absent power failures, of course); usually
not so good hour-by-hour. The guys at the powerhouse use their own power
line output to run a synchronous wall clock, which they compare with an
external reference (this can be done by, say, listening to WWV while
watching the clock). If the second hand leads or lags, they slow down or
speed up their alternators.

That's how they used to do it; things are probably automated now, but
still, the alternators inevitably run a bit slower under heavy load and
faster when unloaded, so the long term-short term issue still applies.

Isaac

 

[root]

Mark Zenier <mzenier@eskimo.com> wrote:

In article <hi1qve$1q3$1@news.albasani.net>, root <NoEMail@home.org> wrote:

I said in my original post, after twenty years or so, the clocks
are correct to within a minute. The only setting I ever did
was to change the hour +/- to effect the season change.

Do the units display a time? Or are you going by the fact that
the VCR that it's controlling works properly?

If it's the latter, that's because VCRplus is just a compression scheme
for time and channel and the unit translates that with a fixed algorithm
and sends the programming setup to the VCR. It's the clock in the VCR
that matters.

Mark Zenier mzenier@eskimo.com
Googleproofaddress(account:mzenier provider:eskimo domain:com)

The unit shows the time/date, but the display on
mine has lost so many segments you have to know
what it is to read it.

When you first get the unit you program it for
the VCR and cable box. At the designated time
the unit sends an IR signal to turn on the
VCR, then it sends a signal to the cable
box to set the channel, then it sends a
REC signal to the recorder. At the end
of REC the units sends a STOP then PWR
signal to the VCR. At the time it was a
slick idea and the company did very well.

The company nosedived: first after it bought
TV Guide, then after the CEO and other officers
pulled some swindle for which they went to jail.

None of the time functions come from the VCR
or the cable box.

 

[Bruce Esquibel]

root <NoEMail@home.org> wrote:

The unit shows the time/date, but the display on
mine has lost so many segments you have to know
what it is to read it.

I'd guess from your original post it has to have one of those "atomic
clocks" built in, the ones that listen to one of the WWV signals.

I have a bedroom clock that basically runs on a couple AA cells (there is an
adapter if you want to use the project time on ceiling feature) so making
one that fits in a remote isn't any stretch of the imagination.

You said you only needed to set the hour, not minutes or seconds. It's the
same for my clock, you sort of set the TZ and nothing else.

Being it "wakes up" at some interval (no clue, every 10 minutes, once an
hour, no idea) to get the current time, I can see battery life as pretty
long.

It probably would have to be that, no other choice. I used to have that
GEMSTAR crap in a few vcr's and I sort of remember the stand alone remotes,
if the feature wasn't built into the vcr.

That whole system would fail if it couldn't keep time accurately, so
resorting to a more expensive WWV type only makes sense.

I remember the big deal was with people trying to crack the algorithm they
used to create the codes. Last time I looked it seemed a couple people came
up with a 90% answer but still didn't work on the longer codes (7 or 8
digits?).

-bruce
bje@ripco.com

 

[root]

Bruce Esquibel <bje@ripco.com> wrote:

I remember the big deal was with people trying to crack the algorithm they
used to create the codes. Last time I looked it seemed a couple people came
up with a 90% answer but still didn't work on the longer codes (7 or 8
digits?).

-bruce
bje@ripco.com

The encryption algorithm was implemented by a guy
from Caltech (Gemstar's CEO) so that only Gemstar
could create the schedules published in seleted
newspapers. You and a previous poster may be
correct in the wwv option, but I have an
"atomic watch" which is sensitive to orientation
when it is receiving the update. The watch might
be too small to have an omnidirectional antenna.

 

[Bruce Esquibel]

root <NoEMail@home.org> wrote:

The encryption algorithm was implemented by a guy
from Caltech (Gemstar's CEO) so that only Gemstar
could create the schedules published in seleted
newspapers. You and a previous poster may be
correct in the wwv option, but I have an
"atomic watch" which is sensitive to orientation
when it is receiving the update. The watch might
be too small to have an omnidirectional antenna.

I dunno at this point what to think. Guess the answer depends on when that
remote you have was made. I had a couple of them in the past, but don't
remember anything about setting the time on them. The point to making that
statement is, I'm pretty sure I had them in early/mid 90's.

After using my google finger for a bit, I can't find any reference to them
having one of those wwv/wwvb clocks built into them. That feature (radio
clocks as they are called) seem to have gained ground starting in 1999 and
becoming common in home use by 2003 or so.

So I'm going to venture to guess, if it was made before 2000, it's not
likely the "atomic clock" is built into it.

It's pretty obvious the vcrplus+ remote was introduced in november of 1990,
looking at the various product reviews for the next few years, no mention of
it/them having a radio type clock is made, which seems to me would of been a
major selling point.

The problem is, by the late 90's, there is basically no mention of "the
remote" anymore, being the function was already incorporated in most brands
of vcr's.

I'm sure they probably had a stand alone remote until they cratered, so if
that thing is in the "within 10 years" age, the radio clock is likely but
can't be proven by me.

The thing that bothers me is, from the pictures of the VIP-18 I could find,
it seems to be the same one I had in the early/mid 90's. Then again, I could
be wrong about that too. One of them (from the dozens of remotes I've own in
the past) had a "large head" on it, and might of even had some kind of plate
or base it velcro'ed into.

Point was, it wouldn't go any good if you left it on the couch or in a
different room, the base was intended so it was aimed at the vcr when it was
needed.

-bruce
bje@ripco.com