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Graham Slee View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2020 at 4:01pm
Originally posted by Ash Ash wrote:

Why a 200MHz calculation?

It worked.

As for the rest of your questions, I'll let Jon answer them LOL
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ash Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2020 at 4:10pm
So by the logic of "it worked", each ferrite point must act like the start of a new cable?

I kind of understand yet am very confused at the same time.

We are so used to visualising currents as direct current rather than alternating current. The energy propagates through the conductor very differently.


Edited by Ash - 14 Jul 2020 at 4:22pm
Lautus USB or S/PDIF>Majestic>Lautus-R3 TRS-XLR>2xProprius>MySphere 3.1
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jupiterboy Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2020 at 4:40pm
Honestly, my room imposes such dreadful nodes and antinodes on the bass that I'd have a hard time telling if I had the ferrite core right. lol
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2020 at 6:03pm
Originally posted by Ash Ash wrote:

So by the logic of "it worked", each ferrite point must act like the start of a new cable?


That was one way I looked at it.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2020 at 6:09pm
Originally posted by Graham Slee Graham Slee wrote:

Originally posted by Ash Ash wrote:

Why a 200MHz calculation?

It worked.

As for the rest of your questions, I'll let Jon answer them LOL


Thanks Graham. I used your formula to position ferrites on some mains cables. It was not always discernible but seemed to sharpen the picture on the TV.
Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2020 at 6:10pm
Originally posted by jupiterboy jupiterboy wrote:

Honestly, my room imposes such dreadful nodes and antinodes on the bass that I'd have a hard time telling if I had the ferrite core right. lol


That's why we go through the pain for you Wink

Room ratios, BBC acoustical engineering guide, rebuilds, laser cut absorbers, lots of wasted effort and materials (an abandoned new building!), and eventually we arrived at the equivalent of a control room regarding how it sounds... or we can use headphones!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2020 at 6:16pm
Originally posted by Ash Ash wrote:

Finally getting my head around Jon's mental arithmetic there. Calculating the distances for ferrite placement is one thing; what about the qualities of the ferrite itself? Does it have to be a certain size or have a particular inductance or "crystal" resonance?

> I bought some ferrite blocks from Maplin that werea about 30mm long and centred them on the cable at the calculated distance.

Why a 200MHz calculation? For the second harmonic of the fundamental wave?? If you had a 10m cable and the signal amplitude were not significantly attenuated by that length, you could have a series of ferrites along the cable that gradually get closer together by a factor of VF%, as long as they fit on the cable?

> Yes, in theory a longer cable needs more ferrites as you create a node and the wave starts there. In practice one or two was enough but I didn't have an oscilloscope to look at the waveforms so very subjective on my part.

The physical contact that the sheath/insulation makes with the EM shield is also important. I assume that is why users were encouraged to gently and carefully bend the cable slightly along different parts of its length to ensure that the sheath is as separated from the shield as possible. If not, could the filter be bypassed to some extent? I understand that I may be asking too many questions...

> Not sure whether if it would make a difference. Your chance to explore...

One more thing, is velocity factor a similar principle to refractive index? A constant between 0 and 1 that considers the speed of light in the medium compared to the speed of light in free space
(vacuum).

> Yes but different frequency range.

Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
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