Silicon Chip4K Monitor Shoot-Out - September 2015 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: SMDs present challenges and opportunities
  4. Feature: Autonomous Underwater Vehicles by Dr David Maddison
  5. Review: 4K Monitor Shoot-Out by Leo Simpson & Nicholas Vinen
  6. Project: Senator: 10-Inch Bass Reflex Loudspeakers by Design by Allan Linton-Smith, words by Leo Simpson
  7. Feature: Electronex: The Electronics Design & Assembly Expo by Silicon Chip
  8. Product Showcase
  9. Project: USB Charger Regulator With Low-Battery Cut-Out by Nicholas Vinen
  10. Project: Build A 9-Channel Infrared Remote Control by John Clarke
  11. Project: Ultra-LD Mk.4 200W RMS Power Amplifier, Pt.2 by Nicholas Vinen
  12. PartShop
  13. Vintage Radio: The unique GE 675 5-transistor radio by Ian Batty
  14. Subscriptions
  15. Market Centre
  16. Advertising Index
  17. Notes & Errata
  18. Outer Back Cover

This is only a preview of the September 2015 issue of Silicon Chip.

You can view 44 of the 112 pages in the full issue, including the advertisments.

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Items relevant to "Senator: 10-Inch Bass Reflex Loudspeakers":
  • 2-Way Passive Crossover PCB [01205141] (AUD $20.00)
  • Acrylic pieces to make two inductor bobbins (Component, AUD $7.50)
  • 2-Way Passive Loudspeaker Crossover PCB pattern (PDF download) [01205141] (Free)
Articles in this series:
  • Senator: 10-Inch Bass Reflex Loudspeakers (September 2015)
  • 2-Way Crossover For Senator 10-Inch Loudspeakers (October 2015)
Items relevant to "USB Charger Regulator With Low-Battery Cut-Out":
  • Mini 12V USB Power Supply with Low-Battery Cut-out PCB [18107151/18107152] (AUD $2.50)
  • SMD parts for the Mini 12V USB Regulator with Low-Battery Cut-out (Component, AUD $20.00)
  • Mini 12V USB Power Supply with Low-Battery Cut-out PCB pattern (PDF download) [18107152] (Free)
Articles in this series:
  • Install USB Charging Points In Your Car (July 2015)
  • USB Charger Regulator With Low-Battery Cut-Out (September 2015)
Items relevant to "Build A 9-Channel Infrared Remote Control":
  • 9-Channel Infrared Remote Control PCB [15108151] (AUD $15.00)
  • PIC16F88-I/P programmed for the 9-Channel Infrared Remote Control [1510815B.HEX] (Programmed Microcontroller, AUD $15.00)
  • Firmware (HEX) files and source code for the 9-Channel Infrared Remote Control [1510815B.HEX] (Software, Free)
  • 9-Channel Infrared Remote Control PCB pattern (PDF download) [15108151] (Free)
  • 9-Channel Infrared Remote Control Receiver panel artwork (PDF download) (Free)
Items relevant to "Ultra-LD Mk.4 200W RMS Power Amplifier, Pt.2":
  • Ultra-LD Mk.4 Amplifier PCB [01107151 RevC] (AUD $15.00)
  • Ultra-LD Mk3/Mk4 Amplifier Power Supply PCB [01109111] (AUD $15.00)
  • Ultra-LD Mk.4 Amplifier prototype PCB [01107151 RevB] (AUD $2.50)
  • 2 x HN3A51F + 1 x IMX8-7-F + 2 x BC846C transistors for the Ultra-LD Mk.4 Power Amplifier module (Component, AUD $5.00)
  • SA156 plastic bobbin (Component, AUD $1.00)
  • Ultra-LD Mk.3 Power Supply PCB pattern (PDF download) [01109111] (Free)
  • Ultra-LD Mk.4 Amplifier PCB pattern (PDF download) [01107151 RevC] (Free)
Articles in this series:
  • Ultra-LD Mk.4 200W RMS Power Amplifier: Preview (July 2015)
  • Ultra-LD Mk.4 200W RMS Power Amplifier, Pt.1 (August 2015)
  • Ultra-LD Mk.4 200W RMS Power Amplifier, Pt.2 (September 2015)
  • Ultra-LD Mk.4 Power Amplifier, Pt.3: 110W Version (October 2015)

Purchase a printed copy of this issue for $10.00.

By Leo Simpson & Nicholas Vinen 4K monitor shoot-out Fancy a big ultra-high definition (4K) monitor for your PC? The good news is that 4K TVs are becoming cheaper and they are now an interesting proposition for anyone who is frustrated with using two or more monitors with a PC. B ACK IN June 2013, we compared the performance of an LG 32-inch smart HD TV with a Dell 30-inch monitor. The LG TV was cheaper and used less power than the Dell monitor but the latter has considerably higher resolution. But technology has marched on considerably in two years and now 4K TVs are on the market and getting cheaper. My PC set-up in the SILICON CHIP office has two monitors, a Benq 24inch HD 16:10 model and an Acer 16:9 24  Silicon Chip (1920 x 1080 pixels). The Benq is used in Landscape mode while the latter is used in Portrait mode which is good when looking at emails, many websites where you tend to scroll down interminably and long documents. It is great to have the extra screen area which two monitors allow and you can have three or four windows open at any time and rapidly drag and drop stuff from one window to another. So that is good but there is a problem with multiple screens and that is ap- parent when you are moving the mouse from one screen to another – the mouse tends to get lost somewhere off-screen and then there is a lot of frantic jiggling of the mouse until it reappears again, accompanied at times by “unseemly” language. While this is a minor gripe, the recent release of a cheap 42-inch 4K monitor under the Bauhn brand by Aldi stores made me think again. Now I cannot see why anyone would bother buying a 4K TV for watching TV or Blu-ray DVDs. siliconchip.com.au Sure, they do a good job of up-scaling normal HD signals from Blu-ray etc but most people simply would not be able to pick the difference at normal viewing distances; even 20:20 vision or better will not resolve it (and yes, there are 4K Blu-ray players but very few discs are available at present). But if you are going to use a 4K TV set as a PC monitor, that is an entirely different proposition. Your viewing distance is typically less than one metre and if you are looking at a large screen, normal HD leaves a lot to be desired. In fact, that was the main difference with our previous monitor shoot-out. There is no avoiding the fact that the picture detail in a 30-inch 2560 x 1600 monitor is clearly superior to that of 1920 x 1080 pixels on a 32-inch screen. Clearly, if you were considering a 42-inch screen, standard HD at 1920 x 1080 pixels would be woeful and even 2560 x 1600 would be less than ideal. 4K, at 3840 x 2160 pixels (ie, twice that of normal HD), is what you want. When Aldi stores recently had a oneday special on their Bauhn ATVU42515 42-inch 4K TV for $499, I initially didn’t give it a second glance, because I was echoing the above thought: why would you want one for watching TV? Then I thought about the potential advantages of using it as a large PC siliconchip.com.au The above view shows the two units side-by-side, with the Bauhn 42-inch 4K TV set at left and the Philips BDM4065UC 40-inch monitor at right. There’s not much difference between them in terms of picture quality. monitor and decided to hot-foot it down to the nearest Aldi store – I got the last set. At that price, they were certainly popular. But hooking a 4K monitor to a PC is pointless unless the PC’s video card can deliver a 4K signal. For that you will need an HDMI output; preferably HDMI 2.0 but HDMI 1.4 will suffice (we’ll get to the details later). And while my computer did have HDMI outputs, its maximum output resolution was normal HD at 1920 x 1080 pixels. So a better video card was required. After some research, a Gigabyte GeForce 750 GTX video card was purchased and installed in the computer. The Gigabyte card comes with two HDMI outputs and one DisplayPort. The Bauhn set does not have a DisplayPort input so you have use one of its HDMI inputs. Setting up the Bauhn TV was quite straightforward and in the result, the new set takes up only slightly more desk space than my previous 2-monitor set-up with one set in Landscape and one in Portrait mode. However, the total screen area is increased by a factor of about 1.5 and the pixel size is a lot smaller. As with the 32-inch smart TV referred to in the June 2013 article, one the first things to be done with the Bauhn 42-inch TV is for it be set so that it shows no over-scan of the picture. You need to set the aspect ratio to “Just Scan” which means that you get exactly the full picture on the screen. You will find that this is necessary because otherwise part of the task bar at the bottom of the screen is liable to disappear. I should mention the Bauhn set’s menus and the remote control. First, the remote control is poor. You must aim it precisely at the right-hand bottom corner of the screen otherwise it simply won’t respond. The buttons sometimes jam and then are you left wondering why the (expletive deleted) set won’t respond to any other buttons being pressed. The menus are clunky; yep, just clunky and the options for adjusting the picture are quite limited. There is no adjustment for gamma and while you can adjust for brightness, contrast and RGB saturation, you cannot select a particular colour temperature. Having said that, the resulting picture is really quite good and of course, you can go into the settings for the video card itself. And while the viewing angle for a PC monitor is less important than for a TV, viewing the picture off-axis is pretty good; we assume that the LCD panel is an IPS (in-plane switching) type. Overall illumination from the LED back-lighting looks reasonably uniform on normal video program but when you have a uniform white screen, you can see the brighter vertical stripes where the backlighting LEDs are present. In most applications, this should not be a problem. The pixel pitch is very impressive at 104 PPI (pixels per inch) horizontally and vertically, ie, the pixels are square. Unless you peer at the screen very closely or use a magnifying glass, you are simply unaware of the pixels. Compare that pixel count with the 91 PPI count of the above-mentioned Acer 24-inch monitor! And if you compare the Acer 24inch 16 x 9 monitor with the Bauhn 42-incher, the latter is three times larger. In practice though, it seems even larger because you can easily have September 2015  25 Think a 24-inch monitor is big? Not any more – the 24-inch Acer FHD (1920 x 1080) monitor at left is no match for the Bauhn 42-inch UHD (3840 x 2160) TV (right) when it comes to screen real-estate. As well as its much larger screen size, the Bauhn set also has much better resolution, making text easier to read. four, five or six windows open on the screen and while there may be some overlap, you can very easily jump from window to window while they still all remain visible. Admittedly, setting up a “tiled” display in Windows can be a bit unwieldy but it works and the fact that you don’t ever lose the mouse as you move around that large screen is a boon; no more frustration when moving across a two-screen set-up. Latency and mouse response There was bound to be a drawback, of course, and it didn’t take long for that to become apparent – latency and mouse response. In our June 2013 article, we remarked that when we had Windows so that both monitors showed the same picture (duplicate mode) the mouse responded normally on the computer monitor but was “floaty” and vague on the smart TV and this has to do with the internal video processing. The solution to the floaty mouse problem is to set the smart TV into games mode. When that is done, the mouse responds precisely when it is 26  Silicon Chip moved, as it should. Sadly, the Bauhn ATVU42-515 42-inch 4K TV is not a “smart” TV and it does not have anywhere in its on-screen menus where you can set it into games mode. That is most unfortunate, since it means that mouse control is inevitably less precise than it should be. You can play around with mouse settings in the Windows control panel but the result is still less than optimum. We have been in contact with the distributor for Bauhn TVs (www.tempo. org) but they were not able to help. Still, we are hopeful that a software update (performed via the rear USB socket) will fix the problem in future. In the meantime, while the mouse response is adequate (barely), the lack of a games mode really means that the Bauhn TV is not suitable for games applications. That is a pity because in most other respects, it is a fine performer. Of course, games addicts will probably turn up their noses at the Bauhn TV in any case. Even though it displays a fine 4K picture, its refresh rate appears to be a maximum of 30fps (frames per second). This is really not fast enough for a lot of games with fast video action. I should also note that the latency of the screen is also evident in response to a keyboard. If you type at a fast rate, you will notice it. Finally, I should mention the aspect of power consumption. This is stated quite vaguely in the Bauhn specifications as less than 100 watts. In practice, it is typically around 80 watts with a mains input voltage of around 235-240VAC. On standby, it drops to around 285 milliwatts. However, there is one setting you will want to make, if you are going to take advantage of its low standby consumption when your computer goes to sleep. Unless you set the Bauhn to a sleep mode with 10 minutes (the minimum setting) it will continue to draw 80W, even though it may be displaying “no signal”. Overall conclusion: the picture is generally good but a software upgrade and an improvement to the picture menus could make a major difference to this Bauhn set. An alternative way Nicholas writes: when Leo plonked the 4K TV on his desk, it was a great affront to my status as the large-screen guru of the office. My 30-inch Dell monitors suddenly seemed inadequate siliconchip.com.au And that’s the minimum you need for fluid motion. It’s vital for games but any other interactive software (eg, PCB layout ECAD packages) will also benefit from it. Even office-type software is easier to use with a mouse cursor that responds more-or-less instantly. With a 60Hz refresh rate, the response time is going to be somewhere around 1s ÷ 60 = 16.6ms but inevitably, there is some extra delay between the data arriving at the monitor and it appearing on the screen. With a purpose-built monitor, this delay will be minimised whereas with a TV, it could be substantial. As a result, when switching between using Leo’s computer and mine, the experience is like jumping from an old Holden into a 2015 Falcon XR8! Image quality by comparison and clearly I had to do something about this. So in the spirit of one-upmanship I decided that I too needed a 4K monitor; only mine had to be better than his. While I appreciate that TVs are cheaper than monitors, they generally are not the best choice for various reasons. Not being a total cheapskate, once I discovered that similarly-sized 4K monitors are available for just over $1000, I decided that was the way to go. After a little research, it seemed that a Philips BDM4065UC 40-inch monitor would restore my status and I placed an order right away (at company expense, of course!). A courier dropped it off later that week. At 100.5cm diagonal (around 40 inches), it’s a bit smaller than the 42-inch Bauhn TV but you would be hard-pressed to tell the difference unless they were side-by-side. They are both the same resolution, ie, 3840 x 2160 pixels which is often referred to as 4K but is more accurately described as “UHD-1” (cinema 4K is 4096 x 2160 and does not have a 16:9 aspect ratio). Unlike the Bauhn TV, the Philips monitor has a DisplayPort input (as well as two HDMI inputs, one miniDisplayPort and one VGA). Currently, DisplayPort is really the only way to get a 4K picture with a 60Hz refresh rate. siliconchip.com.au The Philips monitor also appears to have more even display brightness; on a blank white screen, you can clearly see vertical white stripes on the Bauhn TV. While the Philips monitor doesn’t have perfectly even illumination (few screens of this size are likely to), it isn’t bad. It even comes with a calibration certificate which shows an ~5% variation in brightness across the display. You don’t normally notice it. While colour rendition on both displays is adequate, I think it’s slightly better on the Philips monitor and you certainly have a lot more scope for adjustment through the on-screen menus. Its calibration certificate also indicates colour uniformity across the display with a specified maximum deltaE of 4. That’s good but not great. One really noticeable difference between the two is that the Philips monitor uses a VA (vertically aligned) LCD panel rather than the IPS (in-plane switching) of the Bauhn. VA screens have a much higher contrast ratio than IPS; in this case an amazing 5000:1. But they don’t have anywhere near as good viewing angles. In other words, once you’re looking at the display slightly off-axis, there is a reduction in brightness and a slight colour shift. You can really notice the high contrast as black areas of the screen appear to be part of some great abyss* which sucks in all visible light, forming an inky dark pool. But if you sit as close to the screen as I do, you will notice a drop-off in brightness in areas near the edges and especially the corners of the screen, as a result of the less-than-ideal These two greatly-magnified views show the pixel structure of the Bauhn ATVU42-515 42-inch 4K TV (top) and the Philips BDM4065UC 40-inch 4K monitor. There’s nothing between them when it comes to resolution. viewing angle. Having said that, with a screen this size, you will probably find yourself moving your head around a bit to see what’s in the corners anyway, which reduces this effect (*note: while looking into the abyss, the abyss may also look into you but only if you have a webcam with poor security). So on balance, the comparison between VA and IPS is fairly even. They both have their advantages. I do like the very small bezel on the Philips monitor compared to my Dell 30-inch model. It looks more modern and you notice it less. One thing to note is that both panels (ie, this one and the Bauhn) suffer from the lack of a proper anti-glare coating. September 2015  27 standby as soon as the computer does. This is my first large LED-backlit monitor and it uses a surprisingly small amount of power at just 56W (measured). That’s with a moderate brightness, more than adequate for indoor work with an open window nearby. It’s quite a bit less than Leo’s TV and substantially less than even one Dell 30-inch monitor, let alone the two I was using before (at more than 100W each!). It barely gets warm. Driving it The big advantage of a large screen (42-inch) monitor is that you can have lots of windows open a and displayed on-screen at the same time, making it easier to jump from one to the other. Eyesight not as good as it used to be? Using the Bauhn UHD TV as a large-screen monitor makes it much easier to manage email, especially if you have lots of folders for archives, etc. Note the slightly uneven lighting across the display. I understand that touch-screens need to be somewhat glossy but all that will happen if you touch this screen is that it will leave smudged fingerprints and I just can’t understand why anybody would prefer a reflective screen in this case. It simply reflects too much of what’s in front of it, especially if the room is well-lit. It doesn’t ruin the experience but it is clearly sub-optimal. User interface & power consumption This Philips monitor has a much better control system than any other I’ve used. That’s because rather than 28  Silicon Chip an inscrutable array of poorly-labelled buttons, it has a 4-way pushbutton joystick at the back. It’s in a position that you can easily reach when sitting in front and because you don’t have to guess which way is up/down/left/right, the menu system is easy to navigate. Pressing and holding the joystick for a few seconds switches the screen on and off. When off, it only uses about one quarter of a watt. If you don’t turn it off and just let it go into standby by itself, power consumption is still under half a watt, which is also very low. Unlike the Bauhn TV, which has a sleep delay, the Philips monitor goes into I’m using the same GeForce GTX 750 video card as Leo. We bought these because they have a relatively recent HDMI implementation and we hoped that it would allow 4K <at> 60Hz. Unfortunately, information on which cards support which version of HDMI is extremely scarce and we subsequently discovered that few if any video cards and monitors support this mode over HDMI, even though the HDMI 2.0 standard which supports it is around 18 months old now. As a result, DisplayPort is really the only option for driving a monitor like this and that’s likely to be the case for some time. The monitor comes with a range of cables, including HDMI, DisplayPort and mini DisplayPort, so once you have the right video card installed, setting it up involves little more than connecting them together. There’s just one trick: by default the Philips BDM4065UC uses DisplayPort version 1.1 and so will only run at 4K/30Hz. You have to go into the onscreen menu and enable DisplayPort version 1.2a and then the 60Hz option will appear on your computer. I was a bit nervous until I discovered this! Other features The Philips monitor has a number of other features which I’m not using but that may be of interest to others. For a start, you may notice that the 3840 x 2160 resolution is exactly twice as many pixels wide and tall as full HD (1920 x 1080). The monitor actually allows you to use multiple signal sources (up to four) to drive different sections of the screen. So, for example, if you had it hooked up to a desktop computer but occasionally brought a laptop home from the office, you could plug the laptop into the same screen and use both computers on it simultaneously. As well as “tiling” the displays, you siliconchip.com.au can also view them as picture-in-picture. Oh, and I should mention that like Leo’s TV monitor, this monitor also has down-ward firing speakers which are normally driven from the audio signal supplied from the computer over the HDMI or DisplayPort cable, although you can simply feed in an analog signal if you prefer. Sound quality is . . . um . . . poor. But it’s good enough to alert you to the arrival of new emails or annoy you when you visit a web page with auto-play video ads. The monitor stand is a very basic affair and is not adjustable but you really don’t need it on a display this big. It takes up most of your field of vision and with a regular desk, it will be at about the right height anyway. Smaller 4K monitors For me, the pixel density of a 40inch 4K monitor is about ideal. It’s similar to the pixel density of the 30inch Dell monitors (at 2160 x 1600) or a 22-inch monitor at 1920 x 1080. You can see the pixels if you look hard enough but they aren’t really obvious. However, if you do a lot of photo editing, desktop layout or other similar jobs, you may prefer a higher pixel density which approaches that of a high-resolution printer. The Philips BDM4065UC has a pixel density of 4.4 pixels per millimetre which equates to 111 PPI. By comparison, the 4K Dell UP2414Q at 23.8 inches has 7.3 pixels per mm or 185 PPI. And this Dell monitor has a high degree of colour accuracy; it’s an IPS panel with an anti-glare coating. The price is similar to the Philips display, so if you have a small desk or simply want a very high pixel density, this might be a good choice. Other options include the Dell P2715Q at 27 inches (6.4 PPmm/163 PPI) and the 31.5-inch Dell UP3214Q (5.5 PPmm/140 PPI). It just depends on what size suits you and how important number of pixels is compared to the display area. As stated earlier, for most software, overall screen area matters more than pixels (although more pixels are usually better). Other manufacturers, including LG Asus and Samsung offer similar products. However Philips and Dell appear to offer the best value at the moment. Conclusion Unless you absolutely need the best colour rendition or can’t fit a large dissiliconchip.com.au The back of the Bauhn TVU42-515 42-inch UHD TV set carries the usual array of inputs and outputs, including three HDMI inputs, composite & component video inputs, two USB inputs, an antenna input and analog and digital audio outputs. There’s also a VGA socket and an audio input socket. This view shows the rear of the Philips BDM4065UC 4K 40-inch monitor. Unlike the Bauhn TV set, it includes a DisplayPort input (as well as the usual HDMI, USB and VGA inputs). In addition, the Philips monitor allows you to use multiple signal sources (up to four) to drive different sections of the screen. play on your desk, the BDM4065UC is one of the best value-for-money large 4K displays available. And unless you simply can’t afford the Philips, I wouldn’t bother messing around with 4K TVs. It’s just so much less hassle to get a proper monitor and the extra few hundred dollars are, in my opinion, well spent. If you must use a TV instead, make sure it has a games mode before you buy it. Even so, you’ll probably be relegated to the same type of purgatory as Leo, constantly chasing your mouse cursor as it jumps around the screen. Finally, please don’t anyone tell Leo that 5K monitors are now available. If he ends up getting one, outdoing him again might be very expensive! Pricing & availability The Philips BDM4065UC is available for $1000-1100 including GST plus P&P from online suppliers such as Scorptec (www.scorptec.com.au – Monitor Cat. BDM4065UC; GeForce 750 GTX Cat. GV-N750OC-2GL), Mwave (www.mwave.com.au – Monitor Cat. AB58995; GeForce 750 GTX SC Cat. AB58983). September 2015  29