Calculating signal loss?

[Mathias]

Hi Experienced Techs, :confused:

I made notes on a recent training course regarding measurements of Loss thru passive devices in a multi-split array.
It was something along the lines of adding ALL the losses together, then subtracting something from something else or other.
I've got the memory capacity of a collander lately (age), so i could do with any helpful tips heading my way in the shape of a formula of some easily understandable kind!

Cheers!

[Bad Cable]

when you say passives do you just mean splitters? if so it's normally written on them, for others like f's or barrels are normally considered to be approx -0.5Db and isolators in the region of -1.5Db, or do you need the signal loss over a distance of cable?

[Mathias]

when you say passives do you just mean splitters? if so it's normally written on them, for others like f's or barrels are normally considered to be approx -0.5Db and isolators in the region of -1.5Db, or do you need the signal loss over a distance of cable?

Yes, yes!... that's the one! Loss in dBmV over distance thru varied cable types (RG59,6,7&11) and passive devices (Isolator & 2,3 and 4Way splitters)
I have a table of MAXIMUM LOSS at particular freq per 10 meter lengths of cable, but can't seem to make use of 'em.... If u know what i mean!!!!!... Any clarity on the matter would be mucho obligato! ;)

[Bad Cable]

okay... for cable types & Db loss over distance try the following:

http://www.timesfiber.com/index.cfm/fuseaction/tech.specSheets/index.cfm


http://bb.commscope.com/eng/support_document/spec_sheets/index.html

both have the Db loss over distance at various Mhz (tfc are the current provider for VM, whereas Commscope were for ex ntl sites pre Nov 2006)

So rough idea of your cable run length, and what Mhz your looking at should give you the answer... for each connection (f connector) minus 0.5Db, and remember a plus signal on digital services is not good, there is a full list somewhere, if I find it I'll send it to you

;)

[Mathias]

okay... for cable types & Db loss over distance try the following:

http://www.timesfiber.com/index.cfm/fuseaction/tech.specSheets/index.cfm


http://bb.commscope.com/eng/support_document/spec_sheets/index.html

both have the Db loss over distance at various Mhz (tfc are the current provider for VM, whereas Commscope were for ex ntl sites pre Nov 2006)

So rough idea of your cable run length, and what Mhz your looking at should give you the answer... for each connection (f connector) minus 0.5Db, and remember a plus signal on digital services is not good, there is a full list somewhere, if I find it I'll send it to you

;)

Nice 1 BC!... I'll Check it out 2night!... Cheers! :)

[imemine]

I'm not sure where to put this question, but when I searched this was the only forum that popped up with splitters.

I hope someone can help me. I have high speed internet and phone coming through one modem. I want to put a splitter in so I can hook up a tv by my computers. Time warner said there would be no speed loss in my internet.

my question is: which splitter? I have a few ranging from 300 MHz to 1000 MHz. they have numbers on the connectors too. Can someone direct me to a site or give me information on what all these mean and which one is best to use?

thank you

M

[The Installer]

The signal loss for splitters will depend on the make of splitter but will be roughly, 2 way- 3.5-4.0dB loss, 3 way- 5.5-6.5dB loss and 4ways in the region of 7dB or so. Isolators used by VM have a loss of 0.5dB.

[thamesvalley]

I have high speed internet and phone coming through one modem. I want to put a splitter in so I can hook up a tv by my computers. Time warner said there would be no speed loss in my internet.


M

This doesn't sound like any virgin media service in the UK?