extending firewire

[marksk918]

the firewire specification put the maximum distance for a signal at about 4.5 meters. i've seen cables with repeaters built in, but 4.5m will put me behind a wall. has anyone seen a schematic for a repeater or amplifier? i'd like to run a line from my cable box, through the attic to my computer (about 30-40 feet)

thanks!

[JohnnyMalaria]

For the cost, you'd be better off buying a repeater. I doubt you could DIY and, if you could, the component costs would far exceed that of a commercial repeater. These are typically $40 to $50.

e.g.,

http://catalog.belkin.com/IWCatProductPage.process?Product_Id=193393

http://www.networktechinc.com/hub-1394.html

[rhegedus]

Can't you just get a longer cable? I have a 10m one with no repeater.

[Jim44]

I've run 30ft with a repeater cable connected to a regular cable no problem.

I got the repeater cable here:
http://www.cablewholesale.com/specs/40e3-50200.htm

[marksk918]

one cable with a repeater and one without wouldn't be too bad (cost wise). i'm going to run some cat5 from my dvd player to my router in the next few days, so that will give me a better idea of the distance.

thanks!

[marksk918]

is the maximum distance of 5m dictated by the strength of the signal or by the wire itself?

i found the following:

According to the standard, the IEEE 1394 "wire" is good for 400 Megabits per second over 4.5 meters. The standard cable uses 28 AWG signal pairs with 40 twist/meter. The power pair in the standard cable is 22 AWG.

Longer cable runs can be achieved by using thicker cable or by lowering the bit rate. DV users, keep in mind that the signaling rate of the Sony DV camcorders is only 100 Megabit per second. Can it use longer cables? The answer is: Yes. Although way outside of the spec, several people have reported successful 100 Mbit/sec transmissions over more than 20 meters using standard cable. There are also reports of thicker cables being used to span lengths of 30 meters or more at 100 Megabit per second.

i figure an hdtv signal is at most 18Mbit/sec.

[Jim44]

Depending on how easy the access is, try it with out the repeater first? Sounds like it might work, but to know for sure, with your devices, I'd try it first.

(In my case, the $30 for the repeatered cable was a small price to pay to ensure success and avoid frustration and irritation if a non-repeatered solution was unsuccessful Your tolerance may vary.)