09-02-2019, 09:44 PM
Robin, something you may find useful, depending on how you display your collection is that it might make things easier by doing the splitting in a different way. For example, if you have half on one wall and the other half on a different wall or shelf, a different arrangement to a single 8-way tap might be better.
Taps and Splitters
All splitters can be used as taps but not all taps can be used as splitters! However, this latter distinction only applies to large networks such as operated by Virgin Media and there is normally no need for them in the preservation world. Even the complex system at the Dulwich Museum is built entirely using splitters. A tap simply 'taps off' the small signal used to feed one receiver and it is not normal to document the wiring at this level, so a simple symbol can be used but the wiring between splitters normally needs to be accurately documented for planning, installation, maintenance, modification and expansion.
So, the pairs of symbols on the left of the drawing below are physically the same unit.
Options
On the right are three ways of achieving the 8-way split and the second one would be better for the scenario I mentioned above. The last one shows how a number of feeds can be connected over a large physical area and is unlikely to appeal to you.
The figures in the symbol are the maximum loss of each unit, rounded up to the next dB and these figures should be added together. Typical specified maximum losses are 3.7dB, 7.5dB and 10.5dB. In the examples, the second and third have losses totalling 12dB whilst the first is 1db better at 11dB but, essentially, all three arrangements achieve the same result.
![[Image: Taps-and-splitters.png]](https://i.postimg.cc/fTVKkzch/Taps-and-splitters.png)
Taps and Splitters
All splitters can be used as taps but not all taps can be used as splitters! However, this latter distinction only applies to large networks such as operated by Virgin Media and there is normally no need for them in the preservation world. Even the complex system at the Dulwich Museum is built entirely using splitters. A tap simply 'taps off' the small signal used to feed one receiver and it is not normal to document the wiring at this level, so a simple symbol can be used but the wiring between splitters normally needs to be accurately documented for planning, installation, maintenance, modification and expansion.
So, the pairs of symbols on the left of the drawing below are physically the same unit.
Options
On the right are three ways of achieving the 8-way split and the second one would be better for the scenario I mentioned above. The last one shows how a number of feeds can be connected over a large physical area and is unlikely to appeal to you.
The figures in the symbol are the maximum loss of each unit, rounded up to the next dB and these figures should be added together. Typical specified maximum losses are 3.7dB, 7.5dB and 10.5dB. In the examples, the second and third have losses totalling 12dB whilst the first is 1db better at 11dB but, essentially, all three arrangements achieve the same result.
