V5 gets BSkyB recognition
BSkyB announced at the end of November 2003 that Vision V5 line powered IRS equipment meets the criteria laid down for multiswitch equipment in IRS installations and can be used on all Sky Homes registered installations. This exciting announcement now makes it possible for installers to make considerable savings in material and labour costs as V5 systems make system planning less complex with more economical use of the system components.

V5 goes several steps further in the development of integrated reception systems than other makes. Passive switches by their nature have huge insertion losses, and in the past active line powered switches were not only power hungry but also usually only had a nominal amount of through gain or even a loss.

Simple Colour Coding
All V5 components have colour-coded input and output connections in accordance with the CAI/BSkyB cable colour protocol to ensure ease of installation. This first step allows the least qualified personnel to connect the components thus making a significant labour cost saving possible.

Low power and high gain
V5 is radically different. V5 multiswitches only power the terrestrial circuit unless a satellite receiver is connected to reduce multiswitch current consumption to 70mA. This makes larger systems possible from smaller power supplies. This low consumption also helps the environment and minimises running costs for landlords. While V5 switches may be low consumption, they also give as much as 10dB gain at 860MHz and 12dB of gain at 2150MHz keeping trunk line levels very low and requiring less gain and output at the headend, thus reducing equipment cost.

V5 multiswitch gain is also configured in a different way to other line powered designs. In the 8, 12 and 16 way V5 multiswitches the gain is staggered in banks of four outputs by 2dB. This makes equalising long and short cable runs to the consumer point much easier and maximises the “signal window”. It means that on a 16 way switch there is the ability to have as much as 65m of difference in the length of the drop cable and still ensure excellent terrestrial analogue and digital performance as well as ensuring the satellite signal performance is maintained.

V5 multiswitches also incorporate combined 10dB input level controls on the high-band and low-band satellite inputs and 17dB level control on the terrestrial input. This helps keep the signal levels the same on all matching outlets regardless of which floor they are situated on.

Flexible Powering
V5 systems can be powered in a number of different ways depending on the needs of the installer. This flexibility increases the design options available and reduces cost. Normally V5 systems are powered via the horizontal polarity cables from the headend amplifier. V5-100 can provide up to 2 amps at 18V to power the multiswitches and LNB.

Alternatively, where power is not available at the headend site, 18V can be injected directly into a V5 multiswitch using a V5-2200 PSU, so powering the system from anywhere in the network. It is also possible to inject 18v onto the horizontal polarity cables using a V5-2200 PSU and DC injector. V5-2200 will provide up to 2.2A, which, is enough for up to 30 multiswitches.

Thirdly, a mains powered multiswitch can be used to power a V5 system on smaller installations, removing the need for expensive amplifiers and power supplies. Where remote powering of the headend is employed, V5 offers the line powered headend / repeater amplifier V5-101 which has the same RF performance as the mains powered version. V5-100 and V5-101 amplifiers will pass up to 2 amps of current on their RF lines.

Amplifier Choice
Both V5-100 and V5-101 have 5 separate amplifiers in one box. The normal individual 4 satellite polarities are provided with 15-22dB of sloped satellite gain and 10dB adjustable attenuators. Satellite slope is pre-fixed at 7dB. On the terrestrial input there is 17dB of gain with 20dB adjustment and 0 to 15dB of slope control. These high quality amplifiers use interstage level controls and push-pull amplifiers for linearity in the terrestrial input. This makes the V5-100 and V5-101 ideal for DTT.

These amplifiers provide 110dBµV maximum output at satellite and 114dBµV (DIN45004B) at terrestrial frequencies. Higher output levels are not normally required because the multiswitches have gain not loss and trunk signal levels can be kept low.

Faultfinding Assistant
Even the best installers may occasionally make mistakes but V5 is designed to help with diagnosis. With voltage running along coaxial cables short circuits are often a concern. But V5-100 has L.E.D. indicators on each polarity designed to ease faultfinding. When powered normally the L.E.D indicators glow green. However, should a short or overload be detected then the L.E.D will glow red as a warning on the polarity with the fault. This can speed fault finding dramatically and therefore save on-site costs.

By disconnecting the trunk cables half way down it is possible to quickly identify whether a problem is occurring above or below the break. Speedy diagnostics save time whereas on passive switch systems each connection will have to be inspected individually.

Normally these faults are simple short circuits where a “whisker” of coaxial cable braid touches the inner conductor in an F connector. In the confines of a small riser in a block of flats these mistakes are easily made but V5 speeds the process to put them right.

Distribution Options
Signal splitting in V5 is achieved with the choice of 3 splitter/taps. They are V5-204 equal splitter with 4dB insertion loss, V5-210 and V5-220, 10 and 20dB taps. These splitter/taps are very high quality with low return loss and excellent flatness to ±0.5dB.

By using a combination of the optimum tap value and adjusting the input level controls of the multiswitches, signal balancing can be achieved over the whole system unlike fixed passive switches where the tap losses are static and no level adjustment is provided.

It should be possible to ensure that signal levels at all outlets fall well within a 10dB window before adjustment of the switch input using the appropriate splitter or tap.

Avoiding lengthy cascades
With V5 the installer gains the benefit of active switches with the simple layout of cascaded switch systems. Lengthy cascades of active products are avoided because each switch is “tapped” off the trunk line so each switch is linked directly to the amplifier, not “daisy chained” in a string.

Care has been taken in the design of the splitter/taps to ensure high quality and low return loss through good matching, screening and component use. Even so we would not normally recommend more than 10 taps being cascaded on one long trunk cable.

If you want to know more about Vision V5 or would like a V5 brochure containing product images and specifications, just contact your wholesaler or your dTV representative.