Nice summary Dan.
Sent from my iPhone
> On Mar 16, 2018, at 3:13 PM, Dan Maguire <danac6la@gmail.com> wrote:
>
> Jim Brown wrote:
>>>> Here's measured data for Harbor Industries RG400.
>>>> These curve shapes are predicted by the wave equations and are typical of
>>>> virtually all transmission lines.
>
> As to common curve shapes, here's Figure 3.1 from the Johnson book on
> transmission lines (Howard Johnson and Martin Graham, "High Speed
> Signal Propagation: Advanced Black Magic", 2003):
>
> https://postimg.org/image/tq941yzcl/
>
> The topmost chart trace with the extra annotation is for a
> transmission line etched on a PCB, the lower six traces are for
> various types of coax. Note that the "loss regions" are common to all
> metallic transmission lines but it may be necessary to extend the
> frequency range to lower values to see them all. The regions are also
> most evident when both loss and frequency are plotted on log scales.
>
> Jim Lux wrote:
>>>> So I wonder what truly horrible coax would look like
>
> Here's a comparison for loss between RG-400 as measured by K9YC and
> RG-174/U per mfg specs.
>
> https://postimg.org/image/zefeswdzp/
>
> The RG-174 is Belden 8216. Per the datasheet, "26 AWG stranded (7x34)
> .019" bare copper-covered steel conductor, polyethylene insulation,
> tinned copper braid shield (90% coverage)".
>
> Datasheets:
>
> http://www.wellshow.com/spec/cable/Harbour-RG400.pdf
>
> https://catalog.belden.com/techdata/EN/8216_techdata.pdf
>
> I couldn't find a comprehensive *Belden* datasheet for RG-400.
>
> BTW, the Johnson and Graham book should not be confused with Walter
> Johnson, "Transmission Lines And Networks", 1950. That's also a very
> good book, but the transmission line model used by Zplots, TLDetails,
> AutoEZ, SimSmith, and several other programs is based on the 2003
> Johnson book.
>
> Dan, AC6LA
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