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MEMORY LAPSE
STANDFIRST
Following on from the successful launch of
the TL 720 time-lapse VCR, Philips have developed an attractively priced
24-hour machine. The TL 24R shares most of the features of its stablemate
including the ultra fast Turbo-Drive deck mechanism and comprehensive on-screen
display, as well as one or two of its less desirable quirks...
COPY
Philips are relative newcomers to the low-end
of time-lapse video recorder market, which is a little surprising considering
their impressive credentials. Not only did they virtually invent the concept of
video cassette recording back in the early 1970s, they have a long history in
video surveillance and a impeccable record of technical innovation in this area.
With that kind of background the TL-24 R
appears to be off to a very good start. It’s the second of two time-lapse VCRs
launched by Philips in the past year or so, the first one being the TL720,
which had a maximum recording time of 720 hours on a standard 3-hour VHS
cassette. The TL-24R looks almost identical to its stablemate, internally as
well as externally, but the key difference is a simpler 3-mode recording
system, that records for up to 24 hours. The other two options are 12 hours,
and standard VHS 3-hour real-time recording mode; audio is recorded at all
speeds.
Philips are particularly proud of the
machine’s centre-mounted Turbo-Drive deck mechanism. In addition to very quick
operation, it has high-speed, fast forward and rewind, which allows for rapid
access to any part of the recording. Winding an E-180 tape from end to end
takes a little over 90 seconds.
Front panel controls have been kept to a
minimum; tape transport is handled by a cluster of keys and the prominent jog/shuttle
dial on the right hand side. The tape hatch and an alphanumeric green fluorescent
display are in the middle of the white fascia.
A numeric keypad on the left side of the panel is used to operate and
enter data into the machine’s menu-driven on-screen display system. Menu options
include setting the built-in time/date generator, event timer, various
operating modes, a security lock and the alarm facilities. More about that in a moment.
Installation couldn’t be much simpler, rear
panel connections comprise a pair of BNC sockets for the composite video input
and output. Two phono/RCA sockets carry line-level audio input and output. All
of the AV inputs and outputs are duplicated on a 21-pin SCART socket. It is the
same type and configuration as those used on domestic televisions and video
recorders, and a small but growing number of video monitors. A 9-way spring terminal is used for the alarm
I/O, serial input and output connections (for communication with a second
machine, for continuous recording), there are also connections for camera
switcher sequencing and a tape-end alarm.
The main on-screen display screen has
sub-menus for the clock, basic operation, alarm configuration, alarm report and
timer programming, at the bottom of the display there is an hour meter. Philips
recommend cleaning and inspection at 1000 hour intervals; various parts --
including the upper and lower head drum and pressure roller -- should also be
serviced or replaced every 2000 hours.
The basic settings menu includes such items
as selecting the recording mode, input selection (BNC or SCART), the position
of the on-screen display, camera
synchronisation and PIN-code operated control lock. The alarm settings menu
is confined to enabling or disabling the alarm function and selecting the reset
time. This determines how long the VCR records in 3-hour mode, following an
alarm input. It also includes a repeat record function, so that when the tape
reaches the end, it is automatically rewound, before recording begins again.
Logging the time and date of alarm events is
the job of the Alarm Chart menu display. It shows the time and date of the eight
most recent alarm-triggered recordings. The start of each sequence can be
quickly accessed by moving a highlight to the relevant entry on the list and
pressing the ‘play’ button. The machine then fast winds to the indicated time
and commences replay. Unfortunately the Alarm Chart is wiped clean if the tape
is removed, or there’s a sustained interruption to the power supply.
A built-in event timer -- similar to the one’s
fitted to older domestic VCRS -- can be programmed to switch the machine on and
off at specified times over a 31-day period. The memory can store a total of
seven ‘blocks’, or it can be set to make one-off recordings at regular daily or
weekly times.
The on-screen display is reasonably intuitive
but the operating software and control layout could have been better thought
out. The menu call button is on the left side of the display panel whilst the
up/down cursor controls are on the right; the ‘OK’, and data entry keys are bunched together on the left side of the
panel. Basically this means most users will end up making a lot of mistakes, until
they get used to the system. We suspect the designers would have benefited from
a quick chat with their colleagues over at the consumer division, who mastered
the finer points of OSD operation some years ago.
Ironically they seem to have learned some
valuable lessons on the subject of tape transport control. A jog/shuttle dial
is probably the most efficient and easy to use means of tape navigation during
replay. The outer shuttle dial provides coarse speed and directional control,
whilst the inner jog wheel steps the recording a frame at a time forwards or
reverse, so that recordings can be reviewed in very close detail.
Whilst the simple, solitary alarm function
appears perfectly straightforward, it does suffer from what appears to be a
major flaw, a problem that it shares with its stablemate, the TL 720R. Assuming
the alarm function is enabled, as soon as an alarm input is received the
machine automatically switches to the 3-hour recording mode for the preset
period (1, 2, 5, 10, 15 minutes or to tape end).Whilst that is happening the letter ‘A’ appears next to the time and
date display on the recording and monitor output, plus the word ‘Alarm’ is
shown on the front-panel. However, as soon as the machine reverts back to
time-lapse mode, both alarm indications disappear!
There are no other signs that the alarm
function has been activated, apart from the entry logged by the Alarm Chart.
That means that unless the operator makes a habit of interrogating the Alarm
Chart, following unattended operation, or before the tape is exchanged, all
records of the event could be lost. It could be easily remedied. A simple
on-screen or front-panel indicator could be left on, or set to flash, to alert
the operator. It would also be a good idea to inhibit the repeat recording
mode, to prevent potentially important recordings from being over-written.
Either of these measures would add little or nothing to the cost.
PERFORMANCE
Philips have a great deal of experience in
the design and construction of video recorders, and it shows. Video recording
quality is excellent at all speeds. Following a 100-hour soak period, resolution
on our sample still managed to top 240 lines on standard grade tape; this
remained more or less constant at all recording speeds. Picture noise levels
were very low indeed, and they could be reduced still further by the use of
high-grade tape. Dot crawl or ‘fizz’ in the picture especially in areas of fine
detail were at a very low level. Colour fidelity is generally very good too, reds
were perhaps a little exaggerated though there was little or no bleeding, even
in areas of high saturation.
A time-lapse VCR is only as good as it’s
ability to replay the tapes it has recorded and in that respect the TL24 does
very well. The tape deck is unusually agile, able to change speed and direction
quickly, with minimal on-screen disturbance or noise. Picture stability is
outstanding in still and slomo replay modes, jitter is at a very low level, any
juddering in the picture can normally be eliminated completely by using the manual
tracking controls. The jog/shuttle control is exceptionally easy to use, and an
absolute godsend when it comes to repeatedly reviewing a short section of a
recording.
Needless to say -- from a hi-fi standpoint -- sound quality in the 12 and 24 hour
modes is pretty dire, with severely attenuated treble response. However, bearing in mind that the TL 24 is
unlikely to be called upon to record anything more complicated than speech and
incidental sounds, it is adequate for the purpose. Audio in the 3-hour is
comparable with the standard VHS mono linear soundtrack.
CONCLUSION
In spite of the lack of a alarm indication
and the slightly illogical OSD controls
the TL 24R comes across as a highly-refined
and attractively priced piece of kit. Recording quality across all speed modes
is at or close to the limits of the VHS format performance envelope.
Installation, as part of a simple single or multi-camera system should pose no
problems whatsoever. Normal operation
is very easy, requiring a minimum of operator training and all the indications
are that with regular service, it should have a long and useful life. In
situations where basic time-lapse functions are more important than
comprehensive alarm facilities, or the machine’s operation can be effectively
monitored, the TL 24 is well worth considering as an alternative to other similarly-specified
models.
PRODUCT SPECIFICATION
Recording System multi-speed VHS, PAL CCIR
Recording speeds 3, 12 or 24 hours (E-180 cassette)
Video input/output composite, 1 volt p-p (BNC)
Audio input/output line-level 50k ohm, unbalanced (RCA/phono)
Alarm input/output N/O, real time record mode enable
Timer 7-event/31-days
Additional Facilities
high-speed tape wind, quick-start deck
mechanism, auto head cleaning, auto repeat, multi-speed replay via jog/shuttle
dial, on-screen display, security lock, hours meter, time/date generator
Power supply 230 VAC 50Hz
Weight 5kg
Dimensions 380 x 338 x 86mm
PSI RATINGS
Product ****
Product design ***
Build quality ****
Ruggedness ****
Operation ***
General functions ***
CCTV functions ***
Ease of use ****
Instructions ****
Manuf. support ***
Performance ****
Video quality ****
Audio ***
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Ó R. Maybury 1997 0409
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