> This doesn't make any sense. There is nothing magnetic about coax
unfortunately nearly everything is magnetic. Most cables have steel conductors that are strongly magnetic. Even if they have no steel, many cables and connectors (everything that is gold-plated) have nickel adhesion layers below the gold. I am doing ferromagnetic resonance experiments, in these I can see the absorption from the cables. Our samples are very thin films (around hundred nm), so even a very thin metal film left from machining will cause a signal as big as the sample. Many people have problems with ferromagnetic resonance caused probably by the dielectric of microwave connectors, even though nobody really knows the reason.
> > has anybody a source of non-magnetic RG174, RG178 or similar coaxial > > cable?
> > Daniel > Perhaps Belden types 7805 or 7805R? They apparently have a solid > copper center conductor instead of stranded copper-clad steel.
I just checked out an example of semi-rigid coax, and the one I looked at used copper for the outer conductor and silver-plated copper (SPC) for the inner.
Unfortunately, when I checked out RG402 and RG405 - the semi-rigid coax that you can buy from most broadline distributors - all the manufacturer's data sheets that I could find used silver-plated copper-clad steel wire for the inner conductor (also known as silver-plated copper weld SPCW). Many of Micro-coax's semi-rigid cables use the same centre conductor, but they do seem to use silver-plated copper centre wires in at least some of their cables - I didn't dig deep enough to find out why.
Semi-rigid cable is nice stuff, but expensive, and if you can't get it from a distributor you quite often have to buy quite a lot more than you need.
If you called up a local manufacturer of semi-rigid cable and told them what you needed and why you needed it you might be able to get a big enough free sample out if them to enable you to check out the approach.
On Oct 6, 4:21 pm, Daniel <inva...@invalid.invalid> wrote:
> Hello,
> has anybody a source of non-magnetic RG174, RG178 or similar coaxial cable?
> Daniel
Yup I needed this to run RF to our optical pumping apparatus. Belden 9221 010. Newark part number 05F1809. The core is all copper, The impedance is 75 ohms.
