On Tue, Mar 15, 2005 at 07:52:09PM +0000, David Kirkby wrote:
<snip>
> >
> > I have melted nylon with 7MHz RF, but I never tried it at 2.4GHz.
> > However, D-factor typically increases as freq. increases.
>
>
> I make no claim about the losses of nylon at RF, since I do not know its
> properties. I'm only saying that testing at one frequency does not tell
> you much about losses at another frequency.
>
> In any case, there are different types of nylon. Perhaps with a search
> of the internet, one might find some properly measured data, but unless
> you know the exact source of the nylon, testing it yourself at the
> frequency of interest is probably the best way.
I dug around my bookshelf and found a bit of data in the ITT Reference
Data for Radio Engineers (4th Edition, 1956, aka "the green bible"):
Nylon 610 (polyhexamethylene-adipamide)
Freq. Dielectric Constant Dissipation Factor (~loss tangent)
60 Hz 3.7 .018
1 Khz 3.50 .0186
1 MHz 3.14 .0218
100 MHz 3.0 .0200
3 GHz 2.84 .0117
This is quite a bit lossier than teflon or polystyrene. From the same
table, nylon will start to distort at 65° C.
--
Bob Nielsen, N7XY n7xy (at) n7xy.net
Bainbridge Island, WA http://www.n7xy.net
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