Gemstar VCRPLUS clock accuracy

[root]

Does anybody have an idea of what kind of clock
mechanism was used in the old VCRplus recording
devices? I have several that are still in use
after something like 20 years and the clock
was never set for time except to reset the hour
setting at seasonal time changes. The minutes
setting was never set and the damned things are
as accurate as the day they were bought. I have
never had a watch that was anywhere near as
accurate.

 

[Sjouke Burry]

root wrote:

Does anybody have an idea of what kind of clock
mechanism was used in the old VCRplus recording
devices? I have several that are still in use
after something like 20 years and the clock
was never set for time except to reset the hour
setting at seasonal time changes. The minutes
setting was never set and the damned things are
as accurate as the day they were bought. I have
never had a watch that was anywhere near as
accurate.
My recorders got the correct time/date from the

tv teletext.

 

[William R. Walsh]

Hi!

Time information is sometimes broadcast alongside whatever programming a
station is normally running. A public television station in your area will
typically be the source, although some commercial stations broadcast the
time as well. The devices might be able to get their time from that signal.

However, the cessation of analog broadcasting may mean that at some point
the automatic clock setting function that these devices may use will no
longer work. I have yet to see a digital converter box that passes or
converts the time signal so that older analog-only reception equipment can
still set its clock automatically. All stations broadcasting digital TV
(ATSC) appear to be sending time signals, but the ones I've seen are not all
correct. Most of them are off by quite a ways.

William

 

[Michael Kennedy]

"root" <NoEMail@home.org> wrote in message
news:hhsheu$vqe$2@news.albasani.net...

William R. Walsh <newsgroups1@idontwantjunqueemail.walshcomptech.com
wrote:
Hi!

Time information is sometimes broadcast alongside whatever programming a
station is normally running. A public television station in your area
will
typically be the source, although some commercial stations broadcast the
time as well. The devices might be able to get their time from that
signal.

However, the cessation of analog broadcasting may mean that at some point
the automatic clock setting function that these devices may use will no
longer work. I have yet to see a digital converter box that passes or
converts the time signal so that older analog-only reception equipment
can
still set its clock automatically. All stations broadcasting digital TV
(ATSC) appear to be sending time signals, but the ones I've seen are not
all
correct. Most of them are off by quite a ways.

William



Thanks for responding, but the Gemstar unit is not a recorder,
it is a smart remote control which runs on batteries.

Oh so its kinda like a remote that you just set the record time on and it
does the rest without having to use the OSD menu to set everything on the
VCR. There was a similar product sold "AS Seen on TV".

 

[root]

Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote:

root wrote:
Does anybody have an idea of what kind of clock
mechanism was used in the old VCRplus recording
devices? I have several that are still in use
after something like 20 years and the clock
was never set for time except to reset the hour
setting at seasonal time changes. The minutes
setting was never set and the damned things are
as accurate as the day they were bought. I have
never had a watch that was anywhere near as
accurate.
My recorders got the correct time/date from the
tv teletext.

No, this is a stand-alone unit much like a remote
control for a TV. You enter a VCRPlus code into
the unit and it turned on your vcr and changed
the cable box to the correct channel for recording.

 

[root]

William R. Walsh <newsgroups1@idontwantjunqueemail.walshcomptech.com> wrote:

Hi!

Time information is sometimes broadcast alongside whatever programming a
station is normally running. A public television station in your area will
typically be the source, although some commercial stations broadcast the
time as well. The devices might be able to get their time from that signal.

However, the cessation of analog broadcasting may mean that at some point
the automatic clock setting function that these devices may use will no
longer work. I have yet to see a digital converter box that passes or
converts the time signal so that older analog-only reception equipment can
still set its clock automatically. All stations broadcasting digital TV
(ATSC) appear to be sending time signals, but the ones I've seen are not all
correct. Most of them are off by quite a ways.

William

Thanks for responding, but the Gemstar unit is not a recorder,
it is a smart remote control which runs on batteries.

 

[William R. Walsh]

Hi!

Thanks for responding, but the Gemstar unit is not a recorder,
it is a smart remote control which runs on batteries.

If memory serves, some of that technology was used in VCRs, but thanks
for clarifying. I'm pretty sure that I've seen a few of those remotes,
although I've never been close enough to examine one. (Nor did I
really have any reason to do so.)

I wouldn't think that the clocks inside these devices could be that
accurate all by themselves. The use of a separate battery or packaged
circuit for timekeeping purposes seems unlikely, although I suppose
something like a capacitor could be used to keep the clock running
while the batteries are changed.

I suppose it could always get the correct time by way of the radio
signals that come from a centrally located time standard, such as an
atomic clock. That would actually be a pretty good way of obtaining
correct time and date information.

William

 

[root]

William R. Walsh <wm_walsh@hotmail.com> wrote:

I suppose it could always get the correct time by way of the radio
signals that come from a centrally located time standard, such as an
atomic clock. That would actually be a pretty good way of obtaining
correct time and date information.

William

The things are too old to pick up such signals. The clock
is amazing, and all by itself.

 

[William R. Walsh]

Hi!

The things are too old to pick up such signals.

Actually, they're not. Both the technology and broadcast have existed for
quite some time now, possibly as far back as the 60s. Radio controlled
clocks are both popular and cheap today, but the time broadcast predates the
sudden proliferation of these devices.

Quartz battery operated clocks can be very good timekeepers, but they're not
perfect no matter how much care is put into making one.

William

 

[hr(bob) hofmann@att.net]

On Jan 3, 11:43 pm, root <NoEM...@home.org> wrote:

Does anybody have an idea of what kind of clock
mechanism was used in the old VCRplus recording
devices? I have several that are still in use
after something like 20 years and the clock
was never set for time except to reset the hour
setting at seasonal time changes. The minutes
setting was never set and the damned things are
as accurate as the day they were bought. I have
never had a watch that was anywhere near as
accurate.

They used the power line for frequency source.

 

On Mon, 4 Jan 2010 19:27:50 -0600, "William R. Walsh"
<newsgroups1@idontwantjunqueemail.walshcomptech.com> wrote:

Hi!

The things are too old to pick up such signals.

Actually, they're not. Both the technology and broadcast have existed for
quite some time now, possibly as far back as the 60s. Radio controlled
clocks are both popular and cheap today, but the time broadcast predates the
sudden proliferation of these devices.

Quartz battery operated clocks can be very good timekeepers, but they're not
perfect no matter how much care is put into making one.

William

Let's say his device had a horrible clock design that was only

guaranteed accurate to +/- 10%. He could still happen to get the
*one* unit that was right on at his normal room temperature.

 

[root]

greenpjs@neo.rr.com <greenpjs@neo.rr.com> wrote:

Let's say his device had a horrible clock design that was only
guaranteed accurate to +/- 10%. He could still happen to get the
*one* unit that was right on at his normal room temperature.

No, I have several of these and they all keep perfect time.
I don't expect we'll get an answer here, but the devices
are something special.

 

[isw]

In article <hi136j$uh0$1@news.albasani.net>, root <NoEMail@home.org>
wrote:

greenpjs@neo.rr.com <greenpjs@neo.rr.com> wrote:

Let's say his device had a horrible clock design that was only
guaranteed accurate to +/- 10%. He could still happen to get the
*one* unit that was right on at his normal room temperature.

No, I have several of these and they all keep perfect time.
I don't expect we'll get an answer here, but the devices
are something special.

What is "perfect"? How do they compare to "network time" (NTP)?

Basically, if they are not regularly synchronized to an external time
standard, there's pretty much zero chance that they're going to show
zero long-term rate error.

Isaac

 

[UCLAN]

root wrote:

Let's say his device had a horrible clock design that was only
guaranteed accurate to +/- 10%. He could still happen to get the
*one* unit that was right on at his normal room temperature.

No, I have several of these and they all keep perfect time.
I don't expect we'll get an answer here, but the devices
are something special.

They're so special that you can't provide us with a model number?

 

[root]

isw <isw@witzend.com> wrote:

In article <hi136j$uh0$1@news.albasani.net>, root <NoEMail@home.org
wrote:

greenpjs@neo.rr.com <greenpjs@neo.rr.com> wrote:

Let's say his device had a horrible clock design that was only
guaranteed accurate to +/- 10%. He could still happen to get the
*one* unit that was right on at his normal room temperature.

No, I have several of these and they all keep perfect time.
I don't expect we'll get an answer here, but the devices
are something special.

What is "perfect"? How do they compare to "network time" (NTP)?

Basically, if they are not regularly synchronized to an external time
standard, there's pretty much zero chance that they're going to show
zero long-term rate error.

Isaac

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.

 

[root]

UCLAN <nomail@thanks.org> wrote:

root wrote:

Let's say his device had a horrible clock design that was only
guaranteed accurate to +/- 10%. He could still happen to get the
*one* unit that was right on at his normal room temperature.

No, I have several of these and they all keep perfect time.
I don't expect we'll get an answer here, but the devices
are something special.

They're so special that you can't provide us with a model number?

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.

 

[William R. Walsh]

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.

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

The technology would most certainly have been available for those
remotes to listen to the WWV time data broadcast. And it would be a
good feature to put there, since many broadcasters and networks
synchronize their clocks to that standard as well. That way there
could not be any real drift between what time it is and what time the
clocks around your house say it is, and no problem with programs being
"clipped" by differing time settings.

The way I see it, it makes perfect sense to have done it that way.

William

 

[UCLAN]

root 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.

Correct to within a minute? Hmmm...figuring that the time would be
fiddled with each time the batteries were replaced (and perhaps at
each time change), that seems reasonable.

 

[Mark Zenier]

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)

 

[root]

UCLAN <nomail@thanks.org> wrote:

root 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.

Correct to within a minute? Hmmm...figuring that the time would be
fiddled with each time the batteries were replaced (and perhaps at
each time change), that seems reasonable.

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.