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JVC SR-L910EK 24-HOUR TIME-LAPSE VCR

 

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WHAT OUR EXPERTS SAY...

Modern electronic devices and manufacturer's quality control procedures are generally pretty reliable nowadays and it is quite unusual for a product not to work the first time it's powered up. It's so rare in fact that when a piece of equipment appears not to be functioning properly, sometimes the last thing you suspect is a fault. Quite often it's a hidden or overlooked control function, an external cause, or the user trying to be clever and not remembering to RTFM*…

 

Unfortunately that's not always the case; we'll come to the fun and games we had trying to get the JVC SR-L910EK 24-hour time VHS lapse VCR to work in just a moment, but first a swift run down of the headline features. It is a compact design, around two thirds the width of a domestic VCR but with the same basic layout, namely a centrally mounted deck mechanism with a display and control panel underneath, flanked on both sides by more control buttons. On the rear panel there are two BNC connectors for composite video input and output. There's a pair of RCA/phono sockets for line-level audio in/out, two minijack sockets for a microphone input and corded remote control (optional), plus a 10-way spring terminal for the alarm input/output connections plus various housekeeping and control functions. It has three video recording and playback modes: 3-hour real-time and 12 and 24-hour time-lapse modes; sound is recorded at all three tape speeds.

 

The L910 has a fairly routine assortment of alarm functions. When it receives an external trigger the VCR switches from time-lapse to 3-hour real-time recording mode for a pre-set period of 5, 15, 30, 60, 120 or 180 seconds, alternatively it will record to the end of the tape or it can be reset manually. At the same time an index code is recorded on the tape, a buzzer sounds (this can be disabled), a flashing indicator appears on the front panel, the alarm output on the rear panel is enabled and the time and date of the first and last eight events are logged. Alarm recordings can also be initiated from standby/stop and timer recording mode; the latter can be programmed to make from one to eight timed recordings up to 365 days in advance, or at the same time on a specified day (or days) every week.

 

Additional facilities include a deck mechanism based on a rigid die cast aluminium chassis, repeat recording (i.e. automatic rewind and record at tape end), series recording (tape end on one L910 triggers start record on another machine), camera switching (when used with an external switcher) and auto Recording Check. This replays a short section of a recording at the beginning of a tape, measures the off-tape FM signal and if it falls below a pre-set threshold, the tape heads are automatically cleaned. The test is repeated and if it fails again an error message appears on the display. Recording continues however, ensuring continuity of coverage. Recording check can also be engaged manually at any time by pressing a button on the front panel.

 

OPERATION

And so we come to our little spot of bother. Everything looked fine when the L910 was connected to a monitor and plugged in for the first time; the front panel lit up with the correct time and status displays, so it was off to a good start. After loading a protected resolution test tape the deck laced up and started playback but nothing appeared on the screen. No picture, no time or menu display, just a blank raster. Peculiar, VCRs always work straight out of the box, so it must be a duff tape? Wrong, another tape was tried and the screen remained blank. Could it be a security function, a control lockout or anti tamper feature perhaps? Time at last to read the instruction book… It turns out the L910 does indeed have a control lock, but it couldn't be responsible for this problem otherwise the tape transport functions wouldn't have worked.

 

So, it must be a lead or connector? They were all checked and swapped around, still nothing. Then we noticed a flashing indicator on the display panel showing 'E-11' (we did spot it earlier but thought it was something to do with tape length at first). A quick check of the troubleshooting appendix revealed this to be an error message indicating no video input. Aha, so it needs a video input to work, we were already mentally knocking off points for what seemed to be an obvious design flaw (in fact it's a helpful video loss indicator, so the L910 score sheet wasn't affected). A colour camera was duly connected and a picture appeared on the screen. Problem solved, or so we thought, there was still no playback function or displays. Having eliminated all of the apparently obvious causes the only thing left was a fault on the VCR. 

 

Before calling JVC for some technical help we whipped the lid off. Everything seemed to be in order. In common with most other VCRs the largest component in the box is the deck mechanism and this continued to behave quite normally. The deck sits on a sparsely populated motherboard in the bottom of the case; three daughter-board PCBs plug into the main board, all of the cables and connectors were in place and nothing appeared to be loose or adrift. Finally, before switching off to replace the lid and we gave each of the daughter-boards a gentle prod. There was no change until we came to the last one -- on the left hand side of the case -- when tapped a numerical display flickered briefly on the screen. Pressing down on the board there was a reassuring click as it seated in its sockets and normal operation was restored.

 

It was a simple enough fault and rare enough not to be a concern so there are no great truths or insights to be drawn from this episode. Nevertheless it was a timely reminder that it's easy to overlook the obvious, and that even companies with a normally excellent track record in quality control can occasionally slip up. 

 

With normal service resumed it was back to the matter in hand. The control layout is function though not particularly ergonomic or especially easy to use. The main transport keys are grouped together on the left side of the front panel, all secondary functions and the on-screen display (OSD) buttons are below the tape hatch. The buttons are small, they are all exactly the same size and the light grey on slightly darker grey labelling isn't especially easy to read. The main menu opens with six choices, (Program Timer, Function, Alarm In, Power Loss, Hour Meter and Clock Set); in most cases selecting an option takes you to a set of sub-menus covering the VCR's various set-up and control functions. 

 

Getting the machine up and running takes no more than a few minutes; adjusting the clock is the first job. The clock set menu brings up a simple time and date display that's altered using the bank of set/shift buttons on the front panel. As a matter of interest the clock is fully Y2K compliant and is programmed to operate until the year 2096 -- JVC are clearly very confident of this machines durability... Incidentally the SR-L910 also recognises that the year 2000 is a leap year; apparently some date-sensitive devices do not and it may well be worth checking any equipment in your care! The remaining installation options are accessed from the Function menu. They include OSD position (one of the four-corners of the screen or off), sharpness (normal or sharp), video mode (auto/colour/black & white) and tape end mode (rewind, repeat, eject or stop). The alarm settings are also included on the function menu, along with switches for the internal buzzer and presets for Summer time adjustment, external camera switching and record time-remain indicator. An hour meter records the time the head drum is moving in hours, the instruction manual gives some brief guidance about service intervals and the replacement of lifed components. We discovered entirely by accident that the hour meter can be easily reset, fortunately 'clocking' time-lapse VCRs has yet become a problem.   

 

Once the basic settings have been entered it only remains to load a tape and select the recording speed. This can be changed at any time, without having to stop the tape. The normal on-screen display shows time date and recording speed. Playback options include normal speed replay, at the speed the recording was made (or one of the other recording modes), reverse play, still frame/field and 9x normal speed picture search. Alarm events can be found quickly using Index Search; the tape fast-winds to the start of the recording and automatically goes into replay mode as it detects an index marker. An RS-232C interface board is available as an optional extra, this enables the VCR to be controlled and its status monitored from a PC.

 

Installation and connection to an alarm system or sensor should be very straightforward in the vast majority of cases. The rear-mounted spring terminal is quick, easy to use and reasonably secure. 

 

PERFORMANCE

After an initial 24-hour soak -- to make sure that the loose board hadn't caused any other problems -- the L910 was subjected to our usual range of VCR tests. Using a high-grade tape our sample managed to resolve a little under 250-lines, which is close to the limits of the VHS performance envelope. This was unaffected by recording or playback speed, though for obvious reasons picture stability did tend to suffer in the time-lapse modes. Replaying a recording at a non-standard speed -- i.e., a 3-hour recording in 12-hour mode replay -- did result in a further loss of stability and a big increase in noise interference. Picture noise levels were very low indeed and the machine did seem to benefit from the use of HG tapes. Colour fidelity was also very good with dot crawl only becoming apparent in areas of high saturation. Still frame stability was excellent and it is possible to step forwards through a recording -- one frame at a time -- without any significant jitter. For some reason there's no reverse frame advance facility, which makes finding a particular frame quite difficult. In fact the relative coarseness of the picture replay controls is a disadvantage when analysing a recording and the machine would greatly benefit from some kind co-ordinated multi-speed replay system.

 

One rather unusual and potentially troublesome quirk of this machine was the way it recorded on-screen menus and displays. This doesn't normally happen. Displays are normally superimposed on the video signal during the latter stages of processing, after it comes off the tape. There is no obvious advantage in being able to record the OSD; in fact the opposite is the case. It is possible that the menu could be inadvertently left on the screen, or put there accidentally, and not seen (the monitor may be switched off or the machine set up for unattended or timer-programmed recording; the OSD will be burnt into the recording and possibly obscure important detail. 

 

Audio is recorded on the standard VHS mono linear edge track and in the 3-hour mode it's as good as anything you'll hear on a decent quality domestic mono VHS video recorder. The upper frequency limit is quite modest -- in hi-fi terms -- but it's more than adequate for speech and incidental sounds. There is a significant increase in noise and a big reduction in treble response on 12-hour mode recordings but it is still adequate for speech -- providing a sufficiently sensitive microphone is used. The 24-hour soundtrack carries predominantly loud bassy sounds, it is just possible to make out speech, though don't bank on it.

 

OVERALL ASSESSMENT

We're inclined to overlook the loose daughter-board. It's not a design flaw -- the board stays put once latched into place -- it might indicate sloppy QC procedures but JVC are normally very reliable in this area so this is probably just an uncharacteristic one-off. Nevertheless the machine does fall down on a couple of points. The first is the rather poor assortment of replay options. A lot can happen in a just a couple of frames of a time-lapse recording so it is important to be able to analyse a recording in close detail, and the only way to do that is with quick and responsive forward and reverse frame advance and slow motion replay. The L910 has forward frame step, normal speed play and reverse play, consequently reviewing a short sequence of tape can be very frustrating. It's not helped by the layout of the tape transport keys and more often than not you find yourself whizzing past the bit your want to look at. The second problem concerns the recordable on-screen display; this has the potential to go unnoticed and could easily result in the loss of valuable information.

 

There's still a lot to commend this machine. Video recording quality is very good indeed and it compares well with rival 24-hour and longer-duration time-lapse VCRs. It is compact, simple to install and reasonably easy to set up and use. Build quality -- apart from our little hiccup-- is good and the solidity of the deck mechanism bodes well for long term reliability. Putting our misgivings to one side for a moment this VCR, like it's rival from Philips, is a cost-effective surveillance solution for a lot of retail premises and small businesses, where 24-hour coverage is appropriate and the facility to record sound could prove useful. It's difficult not to like the L910, but you can't help feeling that if the few rough edges could be ironed out, it would have been so much better.

 

PRODUCT ASSESSMENT

Design and design features                      ***

Circuitry and components                ****

Ease of installation and wiring            ****  

Range and variety of functions            ***    

Accompanying instructions              ****                          

Technical advice and backup            ****     

Value for money                         ***                           

 

* read the f***ing manual

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Ó R.Maybury 1998 2809

 


 

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