What our experts say …
There is a widely held belief within the CCTV and surveillance community that video monitors are much of a muchness. While it is true they all look pretty much alike, and basically do the same job, there is often a world of difference between the best and worst examples, both in terms of performance and reliability; and that is without bringing cost into the equation.
The trouble is, from the outside and without specialist equipment, it is quite difficult to judge things such as picture quality. But the real problem is that a poorly designed monitor can actually reduce the amount of detail contained in video image, without the end user or operator even realising it!
It mainly comes down to resolution, measured in horizontal lines (not to be confused with vertical scng lines), which determines a video monitor’s ability to display fine detail.
Most general-purpose models can resolve between 400 and 500 lines, the same ballpark as the majority of mid-range and general-purpose CCTV cameras, which is all well and good. But clearly loss of detail will occur when a low-end monitor is used with a system that includes any high performance cameras.
This is the market that JVC is addressing with the TM-H140PN and its recently launched stablemates. This particular model has a 14-inch (36cm) colour display with the kind of resolving power that relatively few cameras can match or exceed.
The stated resolution is in the order of 750 lines, and that is well above the industry norm and approaching the kind of performance of specialist monitors. The display tube is a 90-degree deflection type, which has rounded corners and a slightly curved faceplate (compared with the current crop of flat-screen TVs and PC monitors). More about the consequences of that in a moment.
The rest of the specification is uncontroversial. The chassis is dual system and can handle PAL and NTSC signals. It has two switchable video and audio input channels. Channel A is composite video only, Channel B is composite and Y/C (S-Video), with the Y/C input taking precedence.
Most picture parameters can be adjusted using a set of on-screen displays and it has two simple remote control options, for switching input channels and aspect ratio (normal 4:3 or 16:9 widescreen). The mono sound system comprises a one-watt amplifier driving an 8cm speaker mounted on the right side of the case.
Inside the case there are two main printed circuit boards, quite large by current standards. The one in the base contains the power supply, scanning and EHT circuitry, while the one on the right side is responsible for video and audio processing. Both appear to be made to a very high standard and the general quality of construction is very good.
From the outside it all looks relatively normal.
It is housed on a two-tone metal-clad cabinet with ABS plastic front screen surround. On the back panel there is an impressive-looking bank of input and output sockets, and a socket for the mains cable.
The AV sockets are clearly labelled, from the top to bottom they are: Channel A composite input and loop-through (BNC), Channel B composite and S-Video input and loop through (BNC and mini DIN), Channel A and Channel B audio in/out (phono), remote channel and aspect ratio switching (phono).
Set-up & operation
Moving around to the front there is a row of buttons beneath the screen, from right to left they are Phase (hue adjustment on NTSC signals), Chroma, Brightness, Contrast, Menu, Volume/ Select up/down, Under Scan, A & B input select and Power on/off.
Pressing the Chroma, Brightness or Contrast buttons brings up a simple bargraph display on the screen and the level is adjusted using the volume up/down buttons. Under Scan reduces the size of the image by around 10 per cent, allowing the edges of the picture to be seen.
They may otherwise be obscured by the screen surround.
There are two menu displays. The first one appears after pressing the Menu button and this has four selectable items: sharpness, colour temperature, colour system and aspect ratio.
The function is chosen using the phase and chroma buttons and changes made with the volume up/down buttons.
The second menu is called up by pressing Phase and Menu together and this displays a Service menu. This covers horizontal and vertical position, white balance (individual RGB settings), control lock, status display, and remote control on/off.
Holding down the Phase and Menu buttons when switching on displays the option to return the monitor to its factory defaults.
Performance
The monitor’s ability to resolve up to 750-lines is not in doubt, images look clean and sharp, colours are natural looking and accurate on the default settings.
Both contrast and brightness required adjustment though, the latter having a surprisingly narrow range with comparatively little headroom to spare at high brightness levels.
In general, performance is very good. However, the tube faceplate tends to pick up a fair number of reflections from overhead and desk lighting and sunlit windows. This is partially to do with the curvature of the faceplate and any anti-reflective coatings – if it has any – not doing an especially good job.
In the scheme of things it is a relatively minor nuisance, but it is worth installers giving a little more thought than usual to location and lighting.
Monitor manufacturers appear to treat sound almost as an after-thought and the TM-H140 does not set any new benchmarks. There is sufficient volume – provided the side-mounted speaker grille isn’t obstructed – and it is fine for speech and incidental sounds.
<b>What the manufacturer says …</b>
In our opinion, monitors never get enough attention paid to them. The reason is simple – they just look like a TV set with most of the buttons removed. But those in the know appreciate there is a great deal more to a CCTV monitor than meets the eye.
At JVC we have always set great stead by our monitor stable. New models – varying in size and resolution – are always coming through research and development. Our range is second to none, from the tiny 10-inch models right up to the grandstand view 21-inch ‘monsters’.
One of the premier matters for consideration, of course, is resolution. Security staff have to sit in front of banks of monitors all day and fuzzy pictures are going to cause them eye strain irrespective of the size of the screen.
Another issue is durability. Although we know that equipment is usually carefully handled, there are times when ruggedisation is the only answer. The JVC monitors can take tough knocks and still function perfectly.
All JVC monitors are high resolution. Our latest model has the highest number of TV lines in its group – bar none.
It is the new high-tech colour monitor ideal for all security CCTV applications. We maintain it is the highest specification monitor in its class.
The compact 14 inch TM-H140PN delivers exceptionally crisp life-like colour pictures via its more than 750 TV lines of horizontal resolution and is switchable between widescreen (16:9) and regular (4:3) aspect ratios.
Its rugged yet stylish metal cabinet contains all the JVC features which set it apart from competitors in its class. The simple on-screen menu lets users fine-tune the display for individual applications of preferences with added manual controls for volume, colour, brightness and contrast.
The durable TM-H140PN comes with a wired remote control option for A/B channel selection and aspect ratio changeover.
The proof of the pudding is always in the eating. That is why we readily agree to professional scrutiny of our equipment. You don’t have to take the brochure’s word for it!
