Infomania.co.uk » HD

PCTV nanoStick T2 290e Freeview HD DVB-T2 tuner stick

admin — Sat, 19 Feb 2011 00:08:15 +0000

Regular DVB-T tuner cards and tuner sticks will allow your PC to receive and record regular Freeview TV and radio programmes. Things are a bit more complicated if you want to receive Freeview HD, as it uses a new broadcast standard, DVB-T2. This is an improved version of DVB-T which can deliver 40 Mbps in a single channel, compared to a maximum of 24 Mbps from the original version. Another benefit is that it is far less susceptible to electrical interference, such as from tumble driers, heating thermostats or even Christmas tree lights.

The good news is that there are now a couple of DVB-T2 tuner products for PCs. Here at Infomania Towers we’ve been testing the PCTV nanoStick T2 290e. This is a single-tuner USB tuner stick which can tune in both regular DVB-T transmissions as well as DVB-T2. It comes with a software disk, remote control, a short USB extension cable and a puny stick aerial which will be of little use unless you happen to live right next to a TV transmitter.

Rather than install the software we decided to see how far we could get with Windows Media Center on a Windows 7 PC. Tuners for Media Center need to work with BDA drivers, which the PCTV stick does. Happily there was no need to do anything other than connect a TV aerial to the stick and plug it into a USB port. Windows got to work finding the stick and sorting drivers out. All we had to do was to start Windows Media Center, tell it our postcode so it knew which region to get TV listings for and set it up to tune the channels in. Although everything worked fine, tuning was a very slow process – far slower than any TVs we have come across. In fact we thought the software might have crashed except that occasionally the progress indicator did actually increment.

The HD signals in this part of the world are a little weak, as the region has not switched to digital yet. Fortunately the stick seems to be quite sensitive and we receive all the HD channels without a problem. Programme guide listing are another issue however. Microsoft haven’t yet added listings for the HD channels to the EPG. It is possible to get listings to show up for BBC 1 HD, ITV 1 HD and Channel 4 HD by editing the guide setup for those channels and telling the EPG to use the listings for the regular versions of the channels. No solution for BBC HD as yet but we are investigating.

So our experience to date is quite positive except for the missing BBC HD listings. We have been able to successfully view, record and replay HD programmes, although sadly Microsoft seem blind to the benefits of Blu-ray DVD drives so it doesn’t appear possible to transfer HD recordings to Blu-ray disc.

How to check lip sync on your HD satellite receiver

admin — Tue, 28 Apr 2009 21:29:33 +0000

There still seem to be audio synchronisation problems with some HD satellite receivers. If you have doubts about yours you can access a lip sync test signal on the BBC HD channel. A test card is available too, which has surround sound audio channel identifications.

When the channel is off-air the BBC transmits a continuous stream of programme clips, in what is known as the Barker. The test card appears after an hour, with the audio sync test 50 minutes after that.

So one hour after the BBC HD channel programmes come to an end you can see the test card. One hour and fifty minutes after closedown the audio sync test appears.

In brief the audio sync test shows two moving white bars, one vertical and one horizontal. The vertical one is a clapperboard while the horizontal bar shows the video timing relative to the audio. Simply listen to the audio and see where the horizontal bar has reached at the point that the clapperboard sound is heard. The numerical scale will show you how far in advance or behind the pictures are compared to the sound.

Both test signals can conveniently be recorded on a Freesat or Sk+ HD recorder by using the manual recording option BUT you may well find that the audio sync on replay is slightly different to that on live viewing!

For fuller details on the audio sync test signal see the BBC Blog here.

Why Blu-Ray players need better HDMI cables

bill — Sun, 12 Apr 2009 20:49:48 +0000

HDMI cables do the same job for High Definition digital TV signals as SCART cables do for analogue TV. Not only do they convey the picture and sound signals but also some control signals. The original HDMI cable spec, Category 1, allowed for data rates of up to 75 MHZ, which is adequate for a 1080i HDTV signal.

The latest TVs and Blu-Ray DVD players both support 1080p video, which has twice as many lines a second and therefore a higher data rate. Consequently a category 1 cable just doesn’t cut the mustard. Although it might appear to work, it is quite likely to create intermittent problems.

The specification of Category 2 cables requires that they support signals of up to 340 MHz – over four times higher than Category 1. This allows them to support 1080p signals, even allowing for future increases in sample resolution to over 8 bits per colour and frame (refresh) rates of up to 120 frames per second.

So in other words when you hook your £700 TV to your £200 Blu-Ray player, don’t use a £5 cable!

Sky to recall 90,000 Pace HD boxes

bill — Mon, 16 Feb 2009 16:38:24 +0000

Having problems with your Sky HD box? That may be the reason Sky are going to swap out 90,000 boxes made by Pace and which have some sort of non-safety related internal wiring fault, according to reports on Broadband TV News, Digital Spy and other technology websites. Affected customers will reportedly receive a voucher for 3 months free HD viewing in compensation.

The original HD boxes were all made by Thomson but the current generation of Sky HD boxes are made by Pace, Samsing and Amstrad. Some customers with the new generation of boxes had initial problems with lip sync which appeared to have been solved with over-the-air updates last year.

Autopsy of a hard drive

admin — Sun, 15 Feb 2009 20:40:20 +0000

Oops, I dropped my hard drive!

Well to be truthful it had packed up so it wasn’t much of a loss. And it was only a 1Gb drive in the first place. As you can see below once the lid is off all the major mechanical components are exposed. You may have seen elsewhere that a hair or even a particle of smoke is enough to make a hard drive head crash fatally into the disc – so don’t try this at home. Unless your drive has taken a dive too of course.

The disc platter is very rigid. It’s made of aluminium with a magnetic coating and it is spun round at 7200 or 5400 RPM by a motor underneath. The head is a tiny ferromagnetic device that is aerodynamically designed so that it flies above the disk in the air-flow generated by the disk’s rotation. The head generates a magnetic field when current is passed through it so data can be recorded onto the disk. The clever bit is that it also generates a current when a changing magnetic field is passed across it which means that the same head can also be used to read data from the disk.

The drive is controlled by electronic circuitry on a PCB (printed circuit board). The PCB is on the bottom of the drive.

The control circuit moves the actuator arm to position the head over the correct part of the disk. The electronics can tell by reading the formatting information where the invisible magnetic tracks start and stop.