Ferrite Core and Ipod question

[Shane Ross]

[doka15] “Can I connect a firewire drive right to the camera and transfer the footage from P2 to Hard Drive?”

Yes. You don’t need a computer to dump the footage onto a hard drive. There are menu settings in the camera that allow you to direct the camera to offload the footage.

[doka15] “I know you can record to a FireStore drive but can you use an off the shelf portable hard drive to dump to like my iPod? Not record to just transfer?”

Any drive will work, as long as it has a firewire connection and enough room.

Shane

Alokut Productions
http://www.lfhd.net

[Lars Wikstrom]

So I guess I could use an iPod then since it has it’s own internal battery. But the connection I have for it is 6 pin firewire and the camera is a 4 pin FW connection. has anyone used an ipod before to off load footage?

-Lars

[Uli Plank]

Hi Lars,

while I haven’t tried it with an iPod, the only difference between 4-pin and 6-pin FW connectors is the lack of power supply via the cable, the data will be there.

A ferrite core is just an additional measure to make high-speed connnections more realiable, quite a few of the FW cables lying around in my studio had ferrite cores on them from the manufacturer. In many cases a cable without one will work as well.

Regards,

Uli

Author of “DVDs gestalten und produzieren”, a book on professional DVD-authoring in German.

[Lars Wikstrom]

Thanks for the answer. Looking at it it seems to be a magnet of some kind. I wonder what it really does to the signal.

Thanks.

-Lars

[Kerry Brown]

It’s not a magnet. Ferrite cores are used on cables to stop RF from interfering with the signals carried by the cable.
The core and cable combination act as a filter.

KB

[Uli Plank]

For very high frequencies a simple cable is a very complex arrangement of capacitors and coils. This can cause reflections and subsequent enhancement or weakening of some parts of the signal. Think of the ferrite core as something like a sponge that cleans up undesirable ‘dirt’ signals.

Hope this helps,

Uli

Author of “DVDs gestalten und produzieren”, a book on professional DVD-authoring in German.

[Jan Crittenden livingston]

Nice explanation Uli, couldn’t have done better myself.

Best,

Jan

Jan Crittenden Livingston
Product Manager, DVCPRO, DVCPRO50, AG-DVX100
Panasonic Broadcast & TV Systems

[Lars Wikstrom]

That explains it. I have cable that have them already attached but this is the first time I have to attach my own. So I wasn;t sure what it did. Thanks for the detailed explination.

-Lars

[Kerry Brown]

Uli, I disagree with part of your explanation: “For very high frequencies a simple cable is a very complex arrangement of capacitors and coils.” What you say about the charateristics of a cable is right on. The second part I have trouble with. “This can cause reflections and subsequent enhancement or weakening of some parts of the signal. Think of the ferrite core as something like a sponge that cleans up undesirable ‘dirt’ signals.” That is not the purpose of the ferrite core. They stop Radio Frequency (RF) noise and Electromagnetic Interference (EMI) from degrading the signal in cables. Long cables can act as an antenna (in effect). By changing the impedence (with a ferrite core) of the cable you suppress this interference. RF and EMI interference is not limited to tv/radio stations, but also household appliances, computers, cars, etc.
Respectfully, Kerry

[Uli Plank]

Hi Kerry,

of course you are giving the right explanation. I was trying to keep it simple. Technically speaking, the ferrite core is dampening the cable when it might act as a tuned circuit for certain frequencies, so it’s weakening it’s resonance for incoming signals and cable reflections alike.

BTW, one of the worst sources of electromagnetic pollution these days are cell phones. I suppose everybody has already heard the typical sound of a nearby phone on their stereo or iPod headphone by now.

Respectfully,

Uli

Author of “DVDs gestalten und produzieren”, a book on professional DVD-authoring in German.