Terminated and Unterminated Receivers

[Anonymous]

Hi,

The diagram on KAT5.TV states for multidrop that we need terminated and unterminated receivers, however, it only shows transmitters and receivers, not terminated or unterminated specifics ????????

[katman]

Hi Rossbale

I assume this is the diagram you are referring to.



This was written before the Mk2 KAT5 units were available and the receivers had to be ordered as Terminated or Unterminated.

With the Mk2 units, there is only one type of receiver AVRX which has a switchable termination. As supplied it is a terminated unit. Flick a few switches and it becomes an unterminated unit.

AVRX User guide http://www.kat5.tv/docs/avrx.pdf

AVTX User guide http://www.kat5.tv/docs/avtx.pdf

Hope that helps

Keith

[Quinten]

Sorry to resurrect an old thread, but I've just bought two Mk1 Rx and one Mk1 Tx, with the idea of creating a multidrop system (as pictured above) for two rooms (living and bedroom). Which leaves me to the following questions:

1) How can I identify if the Rx units I have are terminated or unterminated?
2) How can I make one unit terminated (if they are both unterminated)?
3) How can I make one unit unterminated (if they are both terminated)?

What is also not clear to me yet is the cat5 cabling at the wall plates, so any more details would be very much appreciated.

[katman]

Sorry to resurrect an old thread, but I've just bought two Mk1 Rx and one Mk1 Tx, with the idea of creating a multidrop system (as pictured above) for two rooms (living and bedroom). Which leaves me to the following questions:

1) How can I identify if the Rx units I have are terminated or unterminated?

Hi Quinten

According to my records the serial number of the receivers you have should be from the following. 01410026, 01410027, 01410028

All of these were supplied as terminated receivers

2) How can I make one unit terminated (if they are both unterminated)?
3) How can I make one unit unterminated (if they are both terminated)?

Conversion between terminated and unterminated is a matter of inserting or removing the termination resistors.

For the Audio channels it is R501 and R507 both 600 ohm shown in red
For the Video channels it is R601 and R607 both 100 ohm shown in yellow



http://www.kat5.tv/images/term_resistors.gif

for converting the Terminated Receiver to an unterminated one you can either unsolder the resistor or just snip one leg with a pair of cutters.

What is also not clear to me yet is the cat5 cabling at the wall plates, so any more details would be very much appreciated.

The cable must run as follows....

TX----RXU-----RX

This can either be done with a dedicated cable having two cables punched down on the rear of the intermediate CAT5 socket or by doing the following...

TX----PatchPanel----RXU----PatchPanel----RX and using a CAT5 doubler at the intermediate location.

Your Mk1 units can also have IR upgrades fitted if you need IR control and SCART switching.

Hope that helps

Keith

[Quinten]

Thanks for the quick reply Keith. I'll confirm those serial numbers tonight (as Graham had a few more than just these), but assuming you are correct, then I should be able to do the 'unterminating' myself (how hard can it be ) by snipping all four resistors, right?

I also finally get the double cat5 termation issue, and why it is preferred to have a patch panel. I may have to buy a small one just for this purpose, although I fortunately only have one cat5 socket to do. Do two cat5 cables fit into the punchdown blocks normally? Although I suspect that puching them down is a small nightmare...

[Quinten]

I've got 01410025, 01410026 and 01410027, Keith

[Quinten]

Last question (I hope)

Can I use one of these to split the cat5?



It would then look something like this:



I believe that the splitter has been wired in parallel

[katman]

Hi Quinten

That splitter will do the job but it MUST BE LOCATED AT THE RXU.

The cable from the splitter to the RXU must be as short as possible. At video frequencies, a long unterminated stub of cable will cause signal reflections in the cable leading to ghosting and instability.

If it was possible to split the signal at source I would have included that as a wiring option.



Regards

Keith

[Quinten]

Ah, cheers for that. How short are we talking about? 1m? 50cm? 5cm?

[katman]

Ah, cheers for that. How short are we talking about? 1m? 50cm? 5cm?

1m will be fine. I hve used one of those with a 0.5m lead because that was the shortest I had.