Technical Notes

1. Using baluns versus mounting the Terminator behind TVs and using cat 5 for LAN instead.

Both methods work perfectly however there are differences in serviceability and longevity between the 2 models.

The Terminators are solid state and fanless which makes them incredibly reliable however they were not designed specifically as a remote device, aspects of the design are better suited to desktop or accessible use.

Another equally compelling argument for baluns is that the units (which rely on convection cooling) will last much longer if housed in a cool environment, exactly what the void behind a hot TV that runs for 12 hours a day is not.

It is highly recommended that baluns be used to mount the units in a central AV room or other desirable cool position that allows easy access to service them should they need to be started after a power issue.

In cases of extremely tight budgets, the units will work behind TVs and save considerable cost if retrofitting but if a system is being installed as part of a refurbishment where cabling would be straight forward using baluns is the right way to go.

2. Cat5e Shielded Versus Unshielded.

When cabling a site for VGA baluns over Cat5e cabling you have a choice of either shielded or unshielded cabling. Unshielded is the standard Cat5e patch leads you would use to connect your computer to your LAN.

Strictly speaking you will get the best possible screen output quality using shielded cabling as it will prevent interference from other nearby devices and electromagnetic fields. Having said this many sites get perfect clarity using standard unshielded cabling.

Shielded cabling will likely add around 50% to your cable costs.

We would suggest that you raise this with your electrician to see if he beleives that interference is likely.

If opting for shielded cable, please consult the documentation that comes with the VGA Baluns for instructions on grounding the units to the sheilding.

Also see note 2 for an intermediate option between the 2 options.

3. Earthing to eradicate shimmer and other signal instabilities.

Some sites have experienced some level of shimmer when cabling past a surce of electromagnetic interference when not running shielded cabling.

These sites have overcome this simply by running a grounding cable and grounding each problem balun to it using the ground fixing screw on the balun's chassis.

You should consult your electrician to establish if he/she believes there is any issues with ground differential before doing this, but it has achieved perfect clarity in sites in the past.

4. Be careful to adhere to Cat5e cabling standards.

Electricians and cabling contractors should carefully adhere to cabling standards. Failure to follow the TIA/EIA 568B standard when cabling (ie especially straight through without splitting the correct pairs) will result in cross talk when using cable lengths over 5 metres.

The visible effect is the appearance of a lack of focus and/or severe ghosting.

5. Length of cable runs.

The recommended maximum cable run for VGA baluns given the Terminator's native resolution is 105 metres.

This has been stretched to up to 140 metres without significant degradation in some sites.

If using very ong cable runs, perhaps consider an earth run also as this may help reduce adverse effects.

6. Using CRTs and VGA-TV converters to support old style displays and MATV distribution systems.

CRT TVs and MATV systems can be supported by Flexicast but there are several issues you should be aware of. Scan conversion to CVBS and S-Video required as inputs to MATV systems or CRT televisions does not achieve the same clarity and vibrance achieved by directly driving the screen via a VGA or HDMI port.

Another issue is that as the needs of the venue change and more screens are required to be driven, MATV systems will struggle to provide enough capacity to carry potentially dozens of pages without very significant cost.

Hybrid systems utilising the direct driving of screens in some areas and using existing MATV systems in others may have validity but given the simplicity and extreme low cost of the equipment to drive the individual screens using the Flexicast system, its best to plan to use existing MATV systems for failover teletext distribution and distribution of video signals within your venue such as SKY, Fox Sports or TVN.

7. Retaining SKY TABText and/or legacy display systems for redundancy.

The Flexicast system is built an a very seasoned distribution platform with vast redundancy.

The same Internet distribution servers serving your Flexicast screens supplies the data feeds powering the in-vision racing information in services such as TVN's, Channel 9's and Channel 7's coverage of premium racing as well as many other industry establishments.

Having said this, nothing is totally infallible and while the quality of Internet access provided by national carriers is now extremely good, it is a smart move to be prepared for the worst.

Given that you are likely to already have a complete racing data system in your venue the best idea by far is to retain this system as well as flexicast so if you were to even have a local outage you can quickly switch televisions to the legacy system until service is restored.

8. Pre-cabling for later adoption of Flexicast systems.

If you are refurbishing your venue but will not be taking up a flexicast system at this time it is still highly recommended that you pre-cable for all future possibilities as its getting harder by the month to find teletext capable televisions and all alternatives are likely to need similar cabling.

Some systems may only require a normal LAN cabling layout with a hub at each screen cluster for example to work well, and indeed this will work for flexicast also albeit in a less serviceable state.

It is important to understand however that to get the most from a Flexicast system individual cable runs should be made from each screen to a central point (ie an AV room) where the Terminators would reside.

If you decide later that you do not wish to use the Flexicast system, this cabling will work for any other LAN based system also as it is totally LAN compatible, simply put a network switch at the central point.

Adopting this design will effectively future-proof your venue.

If you cable with single run from your gateway router to each cluster and then break out from there with a switch or hub and patch to each screen your cabling will not offer the same serviceability of systems.

The type of serviceability we refer to here is the difference between getting out a step ladder to access screen drivers instead of simply walking to your AV room.